Maven多模块，Dubbo分布式服务框架，SpringMVC，前后端分离项目，基础搭建，搭建过程出现的问题

　　现互联网公司后端架构常用到Spring+SpringMVC+MyBatis，通过Maven来构建。通过学习，我已经掌握了基本的搭建过程，写下基础文章为而后的深入学习奠定基础。

　　首先说一下这篇文章的主要内容分为：

　　1、Maven多模块项目的创建；

　　2、Maven与SpringMVC的整合；

　　3、Dubbo的环境配置及与整合；

　　4、新手在整合过程易犯的错误。

　　通过一个简单的demo来说明，大家多多指教，分享经验！

　　一、Maven多模块项目的创建

　　　　我们需要建立一个多模块的maven项目，其目录结构为

　　　　

 　　　其中student-api用于暴露接口；student-service用语处理业务逻辑及调用数据访问对象，返回相应数据；student-web主要用于提供dubbo服务，及其他db、spring、springMVC、mybatis等配置。这样设计能够将业务逻辑与数据访问隔离开，同时贴合了spring目标之一，就是允许我们在开发应用的程序时，能够遵循面向对象（OO）原则中的“针对接口编程”，很大程度上达到松耦合。这里将接口API隔离出来作为dubbo生产者的服务接口，供消费应用调用（在后续详细讲解）。

　　　　1.新建Maven项目

　　　　

　　　   2.选择项目存放路径后，选择创建一个简单的maven项目

　　　　

　　　　3.填写GroupId和ArtifactId,注意选择或者填写版本号

　　　　　

　　　　点击完成后，建立好了student-demo项目。之后删除项目src目录，打开pom.xml将<packaging>jar</packaging>修改为<packaging>pom</packaging>，pom表示它是一个被继承的模块。修改后的pom.xml如下

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.student.demo</groupId>
  <artifactId>student-demo</artifactId>
  <version>1.0.0-SNAPSHOT</version>
  <packaging>pom</packaging>

  <name>student-demo</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>
  <!--模块建立好以后自动生成的-->
   <modules>
      <module>student-service</module>
      <module>student-api</module>
      <module>student-web</module>
  </modules>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>

　　　　在建成的项目student-demo上右键选择Maven Module后创建子项目student-api。

　　　　

　　　　填写子模块名字：

　　　　

　　　　项目类型选择：

　　　　

　　　　点击完成，建立好第一个模块后，同样的过程建立好student-service模块和student-web模块，需要注意的是student-web选择的maven类型是：

　　　　

　　　　修改子模块项目目录中的pom.xml文件，把<groupId>XXX</groupId>和<version>1.0.0-SNAPSHOT</version>去掉，加上<packaging>jar</packaging>，因为groupId和version会继承student-demo中的groupId和version，packaging设置打包方式为jar。例如修改后的student-service模块的pom.xml如下：

<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>com.student.demo</groupId>
    <artifactId>student-demo</artifactId>
    <version>1.0.0-SNAPSHOT</version>
  </parent>
  
  <artifactId>student-service</artifactId>
  <packaging>jar</packaging>
</project>

　　　　至此，maven多模块项目已经创建完成，现在我们需要在student-demo项目的pom中增加<dependencyManagement>标签定义可被子项目继承的第三方依赖包，打包配置，资源插件等，同时注意统一定义依赖的版本，避免冲突。这里还利用Maven配置了profiles，可根据情况增加不同的运行环境，并方便快捷地切换项目运行环境，目前我们只设置了dev开发环境。

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.student.demo</groupId>
  <artifactId>student-demo</artifactId>
  <version>1.0.0-SNAPSHOT</version>
  <packaging>pom</packaging>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <dep.ver.lombok>1.16.10</dep.ver.lombok>
        <dep.ver.druid>1.0.1</dep.ver.druid>
        <dep.ver.mysql>5.1.21</dep.ver.mysql>
        <dep.ver.springframework>4.2.5.RELEASE</dep.ver.springframework>
        <dep.ver.mybatis>3.3.0</dep.ver.mybatis>
        <dep.ver.mybatis-spring>1.3.0</dep.ver.mybatis-spring>
        <dep.ver.pagehelper>4.1.6</dep.ver.pagehelper>
        <dep.ver.aspectjrt>1.5.4</dep.ver.aspectjrt>
        <dep.ver.aspectjweaver>1.8.0</dep.ver.aspectjweaver>
        <dep.ver.servlet>3.1.0</dep.ver.servlet>
        <dep.ver.orika-core>1.4.6</dep.ver.orika-core>
        <dep.ver.javassist>3.20.0-GA</dep.ver.javassist>
        <dep.ver.paranamer>2.7</dep.ver.paranamer>
        <dep.ver.concurrentlinkedhashmap-lru>1.4.2</dep.ver.concurrentlinkedhashmap-lru>
        <dep.ver.gson>2.2.4</dep.ver.gson>
        <dep.ver.guava>15.0</dep.ver.guava>
        <dep.ver.slf4j>1.7.21</dep.ver.slf4j>
        <dep.ver.logback>1.1.7</dep.ver.logback>
        <dep.ver.log4j>1.2.12</dep.ver.log4j>
        <dep.ver.slf4j-log4j12>1.7.5</dep.ver.slf4j-log4j12>
        <dep.ver.logback-ext-spring>0.1.2</dep.ver.logback-ext-spring>
        <dep.ver.dubbo>2.5.3</dep.ver.dubbo>
        <dep.ver.zookeeper>3.4.8</dep.ver.zookeeper>
        <dep.ver.zkclient>0.8</dep.ver.zkclient>
        <dep.ver.commons-lang3>3.1</dep.ver.commons-lang3>
        <dep.ver.jackson>1.9.12</dep.ver.jackson>
        <dep.ver.shiro>1.2.3</dep.ver.shiro>
        <dep.ver.freemarker>2.3.22</dep.ver.freemarker>
        <dep.ver.commons-beanutils>1.9.2</dep.ver.commons-beanutils>
        <dep.ver.junit>4.11</dep.ver.junit>
        <dep.ver.mockito>1.10.19</dep.ver.mockito>
        <dep.ver.joda-time>2.9.3</dep.ver.joda-time>
        <dep.ver.commons-collections4>4.1</dep.ver.commons-collections4>
        <dep.ver.httpclient>4.5.2</dep.ver.httpclient>

        <dep.ver.fastjson>1.2.11</dep.ver.fastjson>

        <plg.ver.maven-resources-plugin>2.7</plg.ver.maven-resources-plugin>
        <plg.ver.maven-compiler-plugin>2.5.1</plg.ver.maven-compiler-plugin>
        <plg.ver.maven-source-plugin>3.0.0</plg.ver.maven-source-plugin>
        <plg.ver.lombok-maven-plugin>1.14.8.0</plg.ver.lombok-maven-plugin>

        <jdk.ver>1.8</jdk.ver>
        <encoding>UTF-8</encoding>
        <center.project.name>${project.artifactId}</center.project.name>
        <profiles.dir>src/profiles</profiles.dir>
        <jackson.version>2.6.0</jackson.version>
  </properties>
  <modules>
      <module>student-service</module>
      <module>student-api</module>
      <module>student-web</module>
  </modules>
  
  <dependencies>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>5.2.4.Final</version>
        </dependency>
    </dependencies>
  
  <dependencyManagement>
        <dependencies>
            <!-- spring -->
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-core</artifactId>
                <version>${dep.ver.springframework}</version>
                <exclusions>
                    <exclusion>
                        <groupId>commons-logging</groupId>
                        <artifactId>commons-logging</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context</artifactId>
                <version>${dep.ver.springframework}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context-support</artifactId>
                <version>${dep.ver.springframework}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-web</artifactId>
                <version>${dep.ver.springframework}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-webmvc</artifactId>
                <version>${dep.ver.springframework}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-jdbc</artifactId>
                <version>${dep.ver.springframework}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-tx</artifactId>
                <version>${dep.ver.springframework}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-aspects</artifactId>
                <version>${dep.ver.springframework}</version>
            </dependency>
            <!-- spring -->
            <!-- db -->
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid</artifactId>
                <version>${dep.ver.druid}</version>
            </dependency>
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>${dep.ver.mysql}</version>
            </dependency>
            <!-- db -->
            <!-- mybatis -->
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis</artifactId>
                <version>${dep.ver.mybatis}</version>
            </dependency>
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis-spring</artifactId>
                <version>${dep.ver.mybatis-spring}</version>
            </dependency>
            <dependency>
                <groupId>com.github.pagehelper</groupId>
                <artifactId>pagehelper</artifactId>
                <version>${dep.ver.pagehelper}</version>
            </dependency>
            <!-- mybatis -->
            <!-- apache -->
            <dependency>
                <groupId>org.apache.commons</groupId>
                <artifactId>commons-lang3</artifactId>
                <version>${dep.ver.commons-lang3}</version>
            </dependency>
            <!-- apache -->
            <!-- commons-beanutils -->
            <dependency>
                <groupId>commons-beanutils</groupId>
                <artifactId>commons-beanutils</artifactId>
                <version>${dep.ver.commons-beanutils}</version>
                <exclusions>
                    <exclusion>
                        <groupId>commons-logging</groupId>
                        <artifactId>commons-logging</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
            <!-- commons-beanutils -->
            <!-- log -->
            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-api</artifactId>
                <version>${dep.ver.slf4j}</version>
            </dependency>
            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>log4j-over-slf4j</artifactId>
                <version>${dep.ver.slf4j}</version>
            </dependency>
            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>jcl-over-slf4j</artifactId>
                <version>${dep.ver.slf4j}</version>
            </dependency>
            <dependency>
                <groupId>ch.qos.logback</groupId>
                <artifactId>logback-classic</artifactId>
                <version>${dep.ver.logback}</version>
            </dependency>
            <!-- log -->
            <!-- dubbo -->
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>dubbo</artifactId>
                <version>${dep.ver.dubbo}</version>
                <exclusions>
                    <exclusion>
                        <artifactId>spring</artifactId>
                        <groupId>org.springframework</groupId>
                    </exclusion>
                    <exclusion>
                        <artifactId>netty</artifactId>
                        <groupId>org.jboss.netty</groupId>
                    </exclusion>
                </exclusions>
            </dependency>
            <!-- dubbo -->
            <!-- zookeeper -->
            <dependency>
                <groupId>org.apache.zookeeper</groupId>
                <artifactId>zookeeper</artifactId>
                <version>${dep.ver.zookeeper}</version>
                <exclusions>
                    <exclusion>
                        <groupId>log4j</groupId>
                        <artifactId>log4j</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
            <dependency>
                <groupId>com.101tec</groupId>
                <artifactId>zkclient</artifactId>
                <version>${dep.ver.zkclient}</version>
                <exclusions>
                    <exclusion>
                        <groupId>log4j</groupId>
                        <artifactId>log4j</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
            <!-- zookeeper -->
            <!-- jackson -->
            <dependency>
                <groupId>org.codehaus.jackson</groupId>
                <artifactId>jackson-core-asl</artifactId>
                <version>${dep.ver.jackson}</version>
            </dependency>
            <dependency>
                <groupId>org.codehaus.jackson</groupId>
                <artifactId>jackson-mapper-asl</artifactId>
                <version>${dep.ver.jackson}</version>
            </dependency>
            <!-- jackson -->
            <!-- aspectj -->
            <dependency>
                <groupId>aspectj</groupId>
                <artifactId>aspectjrt</artifactId>
                <version>${dep.ver.aspectjrt}</version>
            </dependency>
            <dependency>
                <groupId>org.aspectj</groupId>
                <artifactId>aspectjweaver</artifactId>
                <version>${dep.ver.aspectjweaver}</version>
            </dependency>
            <!-- aspectj -->
            <!-- servlet -->
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>javax.servlet-api</artifactId>
                <version>${dep.ver.servlet}</version>
                <scope>provided</scope>
            </dependency>
            <!-- servlet -->
            <!-- javassist -->
            <dependency>
                <groupId>org.javassist</groupId>
                <artifactId>javassist</artifactId>
                <version>${dep.ver.javassist}</version>
            </dependency>
            <!-- javassist -->
            <!-- test start -->
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>${dep.ver.junit}</version>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-test</artifactId>
                <version>${dep.ver.springframework}</version>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.mockito</groupId>
                <artifactId>mockito-core</artifactId>
                <version>${dep.ver.mockito}</version>
                <scope>test</scope>
            </dependency>
            <!-- test end -->
            <!-- google -->
            <dependency>
                <groupId>com.google.code.gson</groupId>
                <artifactId>gson</artifactId>
                <version>${dep.ver.gson}</version>
            </dependency>
            <dependency>
                <groupId>com.google.guava</groupId>
                <artifactId>guava</artifactId>
                <version>${dep.ver.guava}</version>
            </dependency>
            <!-- google -->
            <!-- lombok -->
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>${dep.ver.lombok}</version>
            </dependency>
            <!-- lombok -->
            <dependency>
                <groupId>org.apache.commons</groupId>
                <artifactId>commons-collections4</artifactId>
                <version>${dep.ver.commons-collections4}</version>
            </dependency>
            <dependency>
                <groupId>org.apache.httpcomponents</groupId>
                <artifactId>httpclient</artifactId>
                <version>${dep.ver.httpclient}</version>
                <exclusions>
                    <exclusion>
                        <groupId>commons-logging</groupId>
                        <artifactId>commons-logging</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
        </dependencies>
    </dependencyManagement>
  
  <profiles>
        <profile>
            <id>local</id>
            <build>
                <resources>
                    <resource>
                        <directory>${profiles.dir}/local</directory>
                    </resource>
                </resources>
            </build>
        </profile>

        <profile>
            <id>dev</id>
            <build>
                <resources>
                    <resource>
                        <directory>${profiles.dir}/dev</directory>
                    </resource>
                </resources>
            </build>
        </profile>
    </profiles>

    <build>
        <finalName>${center.project.name}</finalName>

        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
                <version>${plg.ver.maven-resources-plugin}</version>
                <configuration>
                    <encoding>${encoding}</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>${plg.ver.maven-compiler-plugin}</version>
                <configuration>
                    <source>${jdk.ver}</source>
                    <target>${jdk.ver}</target>
                    <encoding>${encoding}</encoding>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-source-plugin</artifactId>
                <version>${plg.ver.maven-source-plugin}</version>
                <configuration>
                    <attach>true</attach>
                </configuration> 
                <executions>
                    <execution>
                        <phase>compile</phase>
                        <goals>
                            <goal>jar</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>
</project>

　　　　在student-api中继承父pom的依赖，并且直接引入。

<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>com.student.demo</groupId>
    <artifactId>student-demo</artifactId>
    <version>1.0.0-SNAPSHOT</version>
  </parent>
  <artifactId>student-api</artifactId>
 
 <dependencies>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>${dep.ver.fastjson}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
        </dependency>
        <!-- google -->
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
        </dependency>
        <!-- google -->

    </dependencies>
</project>

　　　　在student-service中添加继承依赖，添加对student-api的依赖。

<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>com.student.demo</groupId>
    <artifactId>student-demo</artifactId>
    <version>1.0.0-SNAPSHOT</version>
  </parent>
  <artifactId>student-service</artifactId>

  <dependencies>
        <dependency>
            <groupId>com.student.demo</groupId>
            <artifactId>student-api</artifactId>
            <version>1.0.0-SNAPSHOT</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>${dep.ver.fastjson}</version>
        </dependency>

        <!-- oss相关依赖 -->
        <dependency>
            <groupId>com.aliyun.oss</groupId>
            <artifactId>aliyun-sdk-oss</artifactId>
            <version>2.0.7</version>
            <exclusions>
                <exclusion>
                    <groupId>commons-logging</groupId>
                    <artifactId>commons-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- oss相关依赖 结束 -->

        <!-- db -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!-- db -->

        <!-- mybatis -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
        </dependency>
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
        </dependency>
        <!-- mybatis -->

        <!-- spring配置 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
        </dependency>
        <!-- spring配置 -->

        <!-- jackson -->
        <!-- <dependency> -->
        <!-- <groupId>org.codehaus.jackson</groupId> -->
        <!-- <artifactId>jackson-core-asl</artifactId> -->
        <!-- </dependency> -->
        <!-- <dependency> -->
        <!-- <groupId>org.codehaus.jackson</groupId> -->
        <!-- <artifactId>jackson-mapper-asl</artifactId> -->
        <!-- </dependency> -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>${jackson.version}</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>${jackson.version}</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>${jackson.version}</version>
        </dependency>
        <!-- jackson -->

        <!-- log -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>log4j-over-slf4j</artifactId>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jcl-over-slf4j</artifactId>
        </dependency>
        <!-- log -->

        <!-- google -->
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
        </dependency>
        <!-- <dependency> -->
        <!-- <groupId>com.google.code.gson</groupId> -->
        <!-- <artifactId>gson</artifactId> -->
        <!-- </dependency> -->
        <!-- google -->

        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
        </dependency>

        <dependency>
            <groupId>commons-beanutils</groupId>
            <artifactId>commons-beanutils</artifactId>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
        </dependency>

        <dependency>
            <groupId>org.javassist</groupId>
            <artifactId>javassist</artifactId>
        </dependency>

        <!-- aspectj -->
        <dependency>
            <groupId>aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
        </dependency>
        <!-- aspectj -->

        <!-- dubbo -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>dubbo</artifactId>
            <exclusions>
                <exclusion>
                    <artifactId>spring</artifactId>
                    <groupId>org.springframework</groupId>
                </exclusion>
                <exclusion>
                    <artifactId>netty</artifactId>
                    <groupId>org.jboss.netty</groupId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>com.101tec</groupId>
            <artifactId>zkclient</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- dubbo -->

        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
        </dependency>

        <dependency>
            <groupId>cglib</groupId>
            <artifactId>cglib</artifactId>
            <version>3.1</version>
        </dependency>
    </dependencies>
</project>

　　　　在student-web中继承依赖，添加对student-api，student-service的依赖。注意子项目依赖版本都为<version>1.0.0-SNAPSHOT</version>

<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>com.student.demo</groupId>
    <artifactId>student-demo</artifactId>
    <version>1.0.0-SNAPSHOT</version>
  </parent>
  <artifactId>student-web</artifactId>
  <packaging>war</packaging>
  <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>
    
        <dependency>
            <groupId>com.student.demo</groupId>
            <artifactId>student-api</artifactId>
            <version>1.0.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>com.student.demo</groupId>
            <artifactId>student-service</artifactId>
            <version>1.0.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
  <build>
    <finalName>student-web</finalName>
  </build>
</project>

　　　二、Maven与SpringMVC的整合

　　　　1.第一部分已经在项目pom文件中配置了spring的相关依赖

　　　　2.在student-web项目根路径上添加profiles源目录及配置文件

　　　　　注意是建立源文件不是普通文件夹。

　　　　　

　　　　　然后在此源文件夹下建立普通文件夹props，用于存放配置文件。在props下新建db-config.properties资源文件，用于配置mysql，其配置内容为：

database.database=mysql
database.driverClassName=com.mysql.jdbc.Driver
database.url=jdbc:mysql://172.0.0.1:3306/student_data?characterEncoding=utf8
database.user=root
database.password=root
database.show_sql=true

　　　　　在mysql数据库中建立一张简单的student数据表，其结构为：

　　　　　

　　　　　3.在student-web的src/main/resources目录中新建spring文件夹，新建spring-base.xml和spring-dispatcher.xml。其中值得说明一下的是，spring监听器ContextLoaderListener和控制器DispatcherServlet会加载应用上下文。其中上下文参数contextConfigLocation的value值是根应用上下文路径classpath:spring/spring-base.xml，它会被ContextLoaderListener加载bean定义。spring-base.xml中的内容为：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-4.0.xsd">

    <!-- 开启aspectj自动注解 -->
    <aop:aspectj-autoproxy proxy-target-class="true" />

    <context:component-scan base-package="org.student" />
    <context:annotation-config />

    <!-- 配置文件加载 -->
    <bean id="propertyConfigurer"
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="order" value="1" />
        <property name="ignoreUnresolvablePlaceholders" value="true" />
        <property name="locations">
            <list>
                <value>classpath:props/db-config.properties</value>
            </list>
        </property>
    </bean>
    <import resource="classpath:spring/spring-db.xml" />
</beans>

　　　　   同样DispatcherServlet会从classpath:spring/spring-dispatcher.xml加载它的bean。

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
                        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
                        http://www.springframework.org/schema/context
                        http://www.springframework.org/schema/context/spring-context-3.0.xsd 
                        http://www.springframework.org/schema/mvc 
                        http://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <mvc:annotation-driven>
        <mvc:message-converters>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter " />
        </mvc:message-converters>
    </mvc:annotation-driven>

    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" />
    <!-- 相当于注册了DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter两个bean，配置一些messageconverter。即解决了@Controller注解的使用前提配置 -->
</beans>

　　　　　4.在Web.xml中声明DispatcherServlet

　　　　　SpringMVC所有请求都会通过一个前端控制器DispatcherServlet，通过这个控制器将请求委托给应用程序的其它执行单元来处理，所以需要通过web.xml来注册。打开student-web项目目录下src/main/webapp/WEB-INF/web.xml，修改web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    id="schedule-console" version="3.0">
    <display-name>student-web</display-name>

    <!-- web.xml中加载顺序是 context-param -> listener -> filter -> servlet -->
    <!-- spring基础配置文件位置 -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring/spring-base.xml</param-value>
    </context-param>

    <!-- Spring监听 -->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <!-- 设置servlet编码开始 -->
    <filter>
        <filter-name>characterEncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
        <init-param>
            <param-name>forceEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>characterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <!-- 设置servlet编码结束 -->
    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring/spring-dispatcher.xml</param-value>
        </init-param>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

　　　　　5.spring与Mybatis的整合

　　　　　在student-web的src/main/resources目录中新建mybatis文件夹，再在此目录新建mybatis.xml和mapper文件夹。在spring文件夹下新建spring-db.xml用于spring加载mybatis配置。spring-db.xml内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
        http://www.springframework.org/schema/context   
        http://www.springframework.org/schema/context/spring-context-4.0.xsd
        http://www.springframework.org/schema/tx 
        http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">

    <!-- 采用druid作为连接池 -->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
        init-method="init" destroy-method="close">
        <!-- 基本属性 url、user、password -->
        <property name="driverClassName" value="${database.driverClassName}" />
        <property name="url" value="${database.url}" />
        <property name="username" value="${database.user}" />
        <property name="password" value="${database.password}" />

        <!-- 配置初始化大小、最小、最大 -->
        <property name="initialSize" value="1" />
        <property name="minIdle" value="1" />
        <property name="maxActive" value="20" />

        <!-- 配置获取连接等待超时的时间 -->
        <property name="maxWait" value="60000" />

        <!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 -->
        <property name="timeBetweenEvictionRunsMillis" value="60000" />

        <!-- 配置一个连接在池中最小生存的时间，单位是毫秒 -->
        <property name="minEvictableIdleTimeMillis" value="300000" />
        <property name="validationQuery" value="SELECT 'x'" />
        <property name="testWhileIdle" value="true" />
        <property name="testOnBorrow" value="false" />
        <property name="testOnReturn" value="false" />

        <!-- 打开PSCache，并且指定每个连接上PSCache的大小 -->
        <property name="poolPreparedStatements" value="true" />
        <property name="maxPoolPreparedStatementPerConnectionSize"
            value="20" />

        <!-- 配置监控统计拦截的filters -->
        <property name="filters" value="stat" />
    </bean>

    <!-- 配置mybatis的sqlSessionFactory -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="configLocation" value="classpath:mybatis/mybatis.xml" />
        <property name="mapperLocations" value="classpath:mybatis/mapper/*.xml" />
    </bean>

    <!-- mybatis mapper接口扫描 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="org.student.service.mapper" />
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
    </bean>

    <bean id="transactionManager"
        class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource" />
    </bean>

    <!-- 开启@Transactional事务注解 -->
    <tx:annotation-driven transaction-manager="transactionManager" />
</beans>

 　　　三、Dubbo的环境配置及与整合

　　　　　我们已经搭建好student-demo项目来作为provider，为其它服务提供接口，所以我们需要先配置好dubbo提供者，PS：这里不会讲解zookeeper的搭建，请自行百度。其项目结构为：

　　　　　　

　　　　　1.首先在student-web中配置dubbo

　　　　　由于我们已经在student-demo中添加了dubbo和zookeeper的相关依赖，下一步字啊resources目录中建立dubbo文件夹，再新建dubbo-producer.xml，同时在profiles的dev环境中添加dubbo-producer.properties配置文件，设置zookeeper注册中心暴露服务地址，配置group分组，服务端口，注册中心请求超时时间(毫秒)和版本。其中组别＋接口地址＋版本号唯一的标识了一个接口。文件内容为：

student-registry-address=172.0.0.1:2181
student-group=student-min
student-service-port=22026
student-timeout=120000
student-version=1.0.0

　　　　　这样我们就可以来配置dubbo-producer.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans.xsd    
    http://www.springframework.org/schema/beans 
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
    http://code.alibabatech.com/schema/dubbo 
    http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
    
    <context:property-placeholder location="classpath:props/dubbo-producer.properties" ignore-unresolvable="true"/>
    
    <dubbo:application name="provider-student-demo"/>
    <dubbo:registry address="${student-registry-address}" protocol="zookeeper"/>
    <dubbo:protocol name="dubbo" port="${student-service-port}" accesslog="true" />
</beans>

　　　　　2.写一个简单的服务接口
　　　　　1）首先在student-service中建立Student实体类

package org.student.bean;

public class Student {
    private Long id;
    private String name;
    private Integer age;
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    
    
}

　　　　　2）同时在student-api中建立与实体bean对应的DTO类实现Serializable接口，并重写toString方法。一般为了不破坏实体类和数据库表一一对应的接口，我们会新建一个DTO实体类，并且加入一些冗余的字段，作为前后端的传输对象。

package org.student.api.dto;

import java.io.Serializable;

public class StudentDTO implements Serializable{
    
    private static final long serialVersionUID = 1L;
    private Long id;
    private String name;
    private Integer age;
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    
    @Override
    public String toString() {
        return "id = " + id + ", name = " + name + ",age = " + age;
    }
    
    
}

　　　　　3）在student-api中建立StudentApi接口，值得注意的是@service注解中的对象

package org.student.api;

import java.util.List;

import org.student.api.dto.StudentDTO;

public interface StudentApi {
    List<StudentDTO> listStudents();
}

 　　　　　4）在dubbo-producer.xml中注册StudentApi，添加配置：

<dubbo:service interface="org.student.api.StudentApi" ref="studentApi"   group="${student-group}" version="${student-version}" timeout="${student-timeout}" />

　　　　　5）从service业务逻辑层子模块开始编写接口实现，新建在student-service中新建StudentBiz实现StudentApi接口

package org.student.service.biz;

import java.util.List;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.student.api.StudentApi;
import org.student.api.dto.StudentDTO;
import org.student.bean.Student;
import org.student.service.StudentService;

import com.google.common.collect.Lists;

@Service("studentApi")
public class StudentBiz implements StudentApi{
    private Logger logger = LoggerFactory.getLogger(StudentBiz.class);
    
    @Autowired
    private StudentService studentService;
    
    @Override
    public List<StudentDTO> listStudents() {
        List<Student> listStudent = studentService.listStudent();
        List<StudentDTO> listStudentDTO = Lists.newArrayList();
        for(Student student: listStudent){
            StudentDTO studentDTO = new StudentDTO();
            studentDTO.setId(student.getId());
            studentDTO.setAge(student.getAge());
            studentDTO.setName(student.getName());
            listStudentDTO.add(studentDTO);
        }
        return listStudentDTO;
    }
}

　　　　　6）在student-service中创建service层接口StudentService

package org.student.service;

import java.util.List;

import org.springframework.stereotype.Service;
import org.student.bean.Student;

@Service
public interface StudentService {

    List<Student> listStudent();
    
}

　　　　　7）在student-service中实现StudentService接口

package org.student.service.impl;

import java.util.List;

import javax.annotation.Resource;

import org.springframework.stereotype.Service;
import org.student.bean.Student;
import org.student.service.StudentService;
import org.student.service.mapper.StudentMapper;

@Service("studentService")
public class StudentServiceImpl implements StudentService{

    @Resource
    private StudentMapper studentMapper;
    
    @Override
    public List<Student> listStudent() {
        List<Student> listStudent = studentMapper.listStudent();
        return listStudent;
    }

}

　　　　　8）在student-service中创建数据层StudentMapper接口

package org.student.service.mapper;

import java.util.List;

import org.student.bean.Student;

public interface StudentMapper {
    List<Student> listStudent();
}

　　　　　9）在student-web中创建实体映射的XML文件，注意StudentMapper类与sql ID的对应关系

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="org.student.service.mapper.StudentMapper">
    <!--查询字段-->
    <sql id="columns">
        a.id,
        a.name,
        a.age
    </sql>

    <!--查询结果集-->
    <resultMap id="beanMap" type="org.student.bean.Student">
        <result property="id" column="id"/>
        <result property="name" column="name"/>
        <result property="age" column="age"/>
    </resultMap>


    <!--根据主键获取实体-->
    <select id="listStudent" resultMap="beanMap">
        SELECT
        <include refid="columns"/>
        FROM
        student a
    </select>

</mapper>

　　　　   dubbo提供者已创建完成，创建完成子应用结构为

　　　　　　　

　　　　3.为了更好的验证，需要创建一个消费者，跳用dubbo接口，其项目结构与子项目student-web类似，Maven项目类型为Webapp project。为了不冗余介绍，请参考Maven项目搭建方式。其将建完成的结构为：
　　　　　　　　　　　
　　　　作为消费者，student-test项目的dubbo配置有所不同
　　　　1）dubbo-consumer.properties的service-group应该与提供者一致，否者找不到提供者方的接口。同时pom.xml中需要增加对的依赖

<dependency>
    <groupId>com.student.demo</groupId>
    <artifactId>student-api</artifactId>
    <version>1.0.0-SNAPSHOT</version>
</dependency>

student-registry-address=172.0.0.1:2181
student-service-group=student-min
student-service-version=1.0.0
student-service-timeout=120000

　　　　　2）spring-dubbo-consumer.xml的配置及接口调用方式

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
    http://code.alibabatech.com/schema/dubbo
    http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
     
    <dubbo:application name="consumer-student-test" />

    <dubbo:registry address="${student-registry-address}" protocol="zookeeper" />
    
    
    <dubbo:reference id="studentApi" interface="org.student.api.StudentApi"
        group="${student-service-group}" version="${student-service-version}"
        check="false" />
    
</beans>

　　　　　3）调用者的controller层

package org.student.controller;

import javax.annotation.Resource;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.student.api.StudentApi;

@RestController
@RequestMapping("/student")
public class StudentController {
    private static Logger logger = LoggerFactory.getLogger(StudentController.class);

    @Resource
    private StudentApi studentApi;
    
    @RequestMapping(path = "/listStudent", method = RequestMethod.POST)
    public void listStudent(){
        logger.info("get students...");
        logger.info("the data are " + studentApi.listStudents());
    }
}

　　　　　4）服务器同时启动provider和consumer，会看到启动信息

　　　　　　　

　　　　查看zookeeper注册中心发现提供者消费者都已成功注册
　　　　　　　
　　　　　　　

　　　　5）测试接口
　　　　由于我并没有写view层来展示数据，现在只能通过控制台的日志信息来简单测试接口。（logback的用法不做解释）利用浏览器post请求访问
http://172.0.0.1:8080/student-test/student/listStudent，控制台输出为

[http-nio-8080-exec-2] INFO  2016-11-07 18:33:24.450 o.s.c.StudentController[24] - get students...
[DubboServerHandler-172.28.19.7:22026-thread-2] INFO  2016-11-07 18:33:24.729 d.a.o.s.a.StudentApi[58] -  [DUBBO] [2016-11-07 18:3:24] 172.28.19.7:56346 -> 172.28.19.7:22026 - student-min/org.student.api.StudentApi:1.0.0 listStudents() , dubbo version: 2.5.3, current host: 127.0.0.1
[http-nio-8080-exec-2] INFO  2016-11-07 18:33:25.026 o.s.c.StudentController[25] - the data are [id = 1, name = 张三,age = 20]

　　　　四、新手在整合过程易犯的错误。

　　　　1.ClassNotFound异常

严重: Error configuring application listener of class org.springframework.web.context.ContextLoaderListener
java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1332)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1166)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:518)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:499)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:118)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4764)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5303)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1407)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1397)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

　　　　　　eclipse会自动将deployment assembly指定的工程，打成jar包，放入到web-inf/lib目录下，tomcat在发布项目的时候没有同时发布maven依赖所添加的jar包，但是如果在deployment assembly没有配置相应的依赖包，就会抛出异常。解决方法：项目 —> properties -> Deployment Assembly -> Add -> Java Build Path Entries -> 选择Maven Dependencies -> Finish -> OK 把对应的Maven依赖包也发布到tomcat，调试时会自动把那些jar发布到指定目录下，tomcat也能找到那些jar了。
　　　　　　另外，同样的报错可能由于不同的原因造成，如果没有激活Maven profile也会报这种错误，激活profile的方式有很多，通过命令首先需要在pom.xml中用<profiles>配置（详细配置请查看上文）再通过命令行：

mvn install -Pdev #激活dev环境

　　　　　　也可以通过eclipse的配置：项目－－>properties-->Maven-->填写profile名－－>apply-->finish

　　　　　　　　

　　　　　　2.启动student-web，spring创建bean对象失败

十一月 07, 2016 8:19:24 下午 org.apache.catalina.core.StandardContext listenerStart
严重: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.student.api.StudentApi': Cannot resolve reference to bean 'studentApi' while setting bean property 'ref'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'studentApi' is defined
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:359)
  　 ...
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839)
   　...
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'studentApi' is defined
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:698)
at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1175)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:284)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:351)
    ...

　　　　　　spring有强大的注解帮助我们简化很大部分代码，并降低的耦合。@Autowired或@Resource在 Bean 类中使用自动注入功能，但是 Bean 还是在 XML 文件中通过 <bean> 进行定义 —— 也就是说，在 XML 配置文件中定义 Bean，通过@Autowired或@Resource为 Bean 的成员变量、方法入参或构造函数入参提供自动注入的功能。以前通过在spring文件中配置<bean>的方式被移除，仅需要添加一行 <context:component-scan/> 配置就解决所有问题了——Spring XML 配置文件得到了极致的简化。<context:component-scan/> 的 base-package 属性指定了需要扫描的类包，类包及其递归子包中所有的类都会被处理。解决：在spring-base.xml中添加

<context:component-scan base-package="org.student" />

　　　　　　3.消费者访问dubbo接口被拒绝

严重: Servlet.service() for servlet [dispatcher] in context with path [] threw exception [Request processing failed; nested exception is com.alibaba.dubbo.rpc.RpcException: Forbid consumer 172.0.0.1 access service org.student.api.StudentApi from registry 172.0.0.1:2181 use dubbo version 2.5.3, Please check registry access list (whitelist/blacklist).] with root cause
com.alibaba.dubbo.rpc.RpcException: Forbid consumer 172.0.0.1 access service org.student.api.StudentApi from registry 172.0.0.1:2181 use dubbo version 2.5.3, Please check registry access list (whitelist/blacklist). at com.alibaba.dubbo.registry.integration.RegistryDirectory.doList(RegistryDirectory.java:579) at com.alibaba.dubbo.rpc.cluster.directory.AbstractDirectory.list(AbstractDirectory.java:73) at com.alibaba.dubbo.rpc.cluster.support.AbstractClusterInvoker.list(AbstractClusterInvoker.java:260) at com.alibaba.dubbo.rpc.cluster.support.AbstractClusterInvoker.invoke(AbstractClusterInvoker.java:219) at com.alibaba.dubbo.rpc.cluster.support.wrapper.MockClusterInvoker.invoke(MockClusterInvoker.java:72) at com.alibaba.dubbo.rpc.proxy.InvokerInvocationHandler.invoke(InvokerInvocationHandler.java:52) at com.alibaba.dubbo.common.bytecode.proxy0.listStudents(proxy0.java) at org.student.controller.StudentController.listStudent(StudentController.java:25) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498)
....

　　　　　　如果消费者访问的接口路径不正确，则无法调用接口。出现这种错误是我没有把消费者的组设置成提供者的组，解决方法是group保持一致

　　　　　　 　　　　　　

　　　　 　　4.访问所有接口都报404错误 

INFO  2016-11-08 12:42:28.507 o.s.w.s.DispatcherServlet[488] - FrameworkServlet 'dispatcher': initialization started
INFO  2016-11-08 12:42:28.518 o.s.w.c.s.XmlWebApplicationContext[578] - Refreshing WebApplicationContext for namespace 'dispatcher-servlet': startup date [Tue Nov 08 12:42:28 CST 2016]; parent: Root WebApplicationContext
INFO  2016-11-08 12:42:28.519 o.s.b.f.x.XmlBeanDefinitionReader[317] - Loading XML bean definitions from class path resource [spring/spring-dispatcher.xml]
INFO  2016-11-08 12:42:28.657 o.s.b.f.s.DefaultListableBeanFactory[839] - Overriding bean definition for bean 'org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping' with a different definition: replacing [Root bean: class [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping]; scope=; abstract=false; lazyInit=false; autowireMode=0; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=null; factoryMethodName=null; initMethodName=null; destroyMethodName=null] with [Root bean: class [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping]; scope=; abstract=false; lazyInit=false; autowireMode=0; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=null; factoryMethodName=null; initMethodName=null; destroyMethodName=null]
...
INFO  2016-11-08 12:42:29.545 o.s.w.s.m.m.a.RequestMappingHandlerAdapter[532] - Looking for @ControllerAdvice: WebApplicationContext for namespace 'dispatcher-servlet': startup date [Tue Nov 08 12:42:28 CST 2016]; parent: Root WebApplicationContext
INFO  2016-11-08 12:42:29.810 o.s.w.s.v.v.VelocityConfigurer[140] - ClasspathResourceLoader with name 'springMacro' added to configured VelocityEngine
INFO  2016-11-08 12:42:30.193 o.s.w.s.DispatcherServlet[507] - FrameworkServlet 'dispatcher': initialization completed in 1684 ms
WARN  2016-11-08 12:42:30.206 o.s.w.s.PageNotFound[1136] - No mapping found for HTTP request with URI [/student/listStudent] in DispatcherServlet with name 'dispatcher'

　　　　　　这个错误我找了很久才发现，并不是简单的访问路径错误。仔细查看日志信息会发现spring加载dispatcher的过程，截取在web.xml中配置

<!--spring加载-->
<context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring/spring-base.xml</param-value>
</context-param>
...

<!--springMVC加载-->

<servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring/spring-dispatcher.xml</param-value>
        </init-param>
</servlet>
<servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
</servlet-mapping>

　　　　　　在Tomcat启动时，web.xml中加载顺序是 context-param -> listener -> filter -> servlet，ContextLoaderListener基于Web上下文级别的监听器在启动服务器时就创建ApplicationContext并且将配置的Spring Bean加载到XML中。DispatcherServlet是一个请求分发控制器，所有匹配的URL都会通过该Servlet分发执行，在创建Servlet对象时会初始化Spring MVC相关配置。spring-dispatcher.xml中定义了控制器映射，使用Controller+RequestMapping注解映射时，相关controller组件扫描要定义在spring-dispatcher.xml中，而非spring-base.xml中。依据这样的分析，我去查看了student-test项目中spring-dispatcher.xml和spring-base.xml的配置，发现spring-base.xml配置了

<context:component-scan base-package="org.student"/>

　　　　　　而在spring-dispatcher.xml中未配置扫描路径。所以spring无法加载controller中的映射，自然会404了，解决方式则是在spring-dispatcher.xml中加上扫描。

　　　　　　至此，这是所有我想介绍的内容，欢迎大家批评指正，转载请注明出处http://www.cnblogs.com/blueness-sunshine/p/6015965.html，另外想要源码的朋友可以留言，谢谢。

　　　　　　博客推荐：

　　　　　　   http://blessht.iteye.com/blog/2121845

　　　　　　　 http://www.cnblogs.com/szlbm/p/5512931.html

　　　　　　　 http://blog.csdn.net/congcong68/article/details/41113239

　　　　　PS:太多朋友需要源码，可能没有及时回复邮件。现我已上传至Github，请自行下载，欢迎大家多做交流。
　　　　　student-demo
　　　　　student-test