SpringMvc+Mybatis+Maven+Mysql做一个CRUD的简单例子
本文档结合 SpringMVC、 Mybatis、 MySQL,说明如何实现一个简单的数据库单表 CRUD操作。开发工具使用集成了spring mvc的eclipse(Spring Tool Suite,简称STS)。
基础环境说明
- Mac OS X 10.11.5
- jre version 1.8.0_05
- java sdk 1.8.0_05
- STS 3.5.1
- maven 3.2.1
以上环境安装配置好后,就可以开始demo程序了。
MySQL建表语句
CREATE TABLE `user` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(20) NOT NULL, `age` int(11) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=big5
Step 1 新建spring mvc项目
使用STS新建一个spring mvc project,建立好项目后,一个基本的spring mvc web项目已经搭建 好,我们只需要在这之上配置好相关的beans,以及编写CRUD相关的代码。
可以注意一下项目中的 web.xml、 servlet-context.xml,STS已经帮我们把跟spring 相关的基本配置项配置好。
例如:web.xml中定义了请求由spring接管,以及IOC相关的配置文件名称。
<?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="WebApp_ID" version="3.0"> <servlet> <servlet-name>mybatis</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>mybatis</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>
Step 2 使用maven加载所需的jar包
如果使用独立安装的maven程序,需要在eclipse中指定maven的路径:
Preferences — Maven — Installations
例如,我的路径是:/usr/local/maven/maven3.2.2
maven配置好后,就可以在pom文件中添加相关的依赖项了,需要添加的相关依赖配置如下:
<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.goody9807.mybatis</groupId> <artifactId>mybatis_web</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>war</packaging> <name>mybatis_web</name> <properties> <org.springframework-version>3.2.3.RELEASE</org.springframework-version> <slf4j-version>1.5.11</slf4j-version> </properties> <dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${org.springframework-version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>${org.springframework-version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>${org.springframework-version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>${org.springframework-version}</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.31</version> </dependency> <dependency> <groupId>commons-dbcp</groupId> <artifactId>commons-dbcp</artifactId> <version>1.4</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.2.2</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.2.7</version> </dependency> <!-- https://mvnrepository.com/artifact/log4j/log4j --> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.14</version> </dependency> <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-log4j12 --> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>${slf4j-version}</version> </dependency> <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-nop --> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-nop</artifactId> <version>${slf4j-version}</version> </dependency> <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-jdk14 --> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-jdk14</artifactId> <version>${slf4j-version}</version> </dependency> <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-simple --> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-simple</artifactId> <version>${slf4j-version}</version> </dependency> </dependencies> </project>
需要注意跟spring相关的jar包的版本问题
保存pom文件后会自动根据配置文件下载所需的jar包。
Step 3 主要配置示例
bean相关配置
在mybatis-servlet.xml配置文件中增加如下的bean,注意schema格式 数据源:
<?xml version="1.0" encoding="UTF-8"?> <beans:beans xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:beans="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:util="http://www.springframework.org/schema/util" xmlns:p="http://www.springframework.org/schema/p" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd"> <context:component-scan base-package="goody9807.springdemo" /> <mvc:annotation-driven /> <!-- 允许对静态资源文件的访问 --> <mvc:default-servlet-handler /> <!-- 定义跳转的文件的前后缀 ,视图模式配置 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/view/" /> <property name="suffix" value=".jsp" /> </bean> <beans:bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" lazy-init="default" autowire="default"> <beans:property name="driverClassName" value="com.mysql.jdbc.Driver"> </beans:property> <beans:property name="url" value="jdbc:mysql://127.0.0.1:3306/test"></beans:property> <beans:property name="username" value="root"></beans:property> <beans:property name="password" value="123456"></beans:property> </beans:bean> <beans:bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <beans:property name="configLocation" value="spring-mybatis-config.xml"></beans:property> <beans:property name="dataSource" ref="dataSource" /> </beans:bean> <beans:bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <beans:property name="basePackage" value="goody9807.springdemo.da" /> </beans:bean> </beans:beans>
Mybatis Sql Session配置:
由spring接管的mybatis session,configLocation配置的value要和实际的mybatis配置 文件一致。
Mybatis主配置文件
spring-mybatis-config.xml配置文件示例如下:
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <settings> <setting name="cacheEnabled" value="true" /> <setting name="lazyLoadingEnabled" value="true" /> <setting name="aggressiveLazyLoading" value="false" /> <setting name="multipleResultSetsEnabled" value="true" /> <setting name="useColumnLabel" value="true" /> <setting name="useGeneratedKeys" value="false" /> <setting name="autoMappingBehavior" value="PARTIAL" /> <setting name="defaultExecutorType" value="SIMPLE" /> <setting name="defaultStatementTimeout" value="25000" /> <setting name="safeRowBoundsEnabled" value="false" /> <setting name="mapUnderscoreToCamelCase" value="false" /> <setting name="localCacheScope" value="SESSION" /> <setting name="jdbcTypeForNull" value="OTHER" /> <setting name="lazyLoadTriggerMethods" value="equals,clone,hashCode,toString" /> </settings> <typeAliases> <typeAlias alias="User" type="goody9807.springdemo.model.User" /> </typeAliases> <mappers> <mapper resource="config/mapper/user.xml" /> </mappers> </configuration>
mapper文件
例如:mapper/user.xml
<?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="goody9807.springdemo.da.UserMapper"> <select id = "get" parameterType="int" resultType="User"> select * from user where ID=#{id}; </select> <insert id="insert" parameterType="User"> insert into user values (#{id}, #{name}, #{age}); </insert> <update id="update" parameterType="User"> update user set name=#{name},age=#{age} where id=#{id}; </update> </mapper>
Step 4 主要代码
定义Model User.java
package goody9807.springdemo.model; public class User { private int id; private String name; private int age; public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public int getId() { return id; } public void setId(int id) { this.id = id; } }
定义CRUD操作接口
UserMapper.java
package goody9807.springdemo.da; import goody9807.springdemo.model.User; public interface UserMapper { User get(int id); void insert(User u); void update(User u); }
编写Action
在Controller中增加CRUD相关的action。需要先将数据操作的mapper类注入到controller中,增加 代码如下:
@Autowired private UserMapper _userMapper;
get一个数据实体
@RequestMapping(value = "/get/{id}", method = RequestMethod.GET) public String get(@PathVariable("id") int id, Model model) { User u = _userMapper.get(id); model.addAttribute("user", u); return "user"; }
注解RequestMapping说明对应的url,以及http method,其中{id}代表URL参数,和action中的参 数id对应,同时需要在参数id前增加注解:@PathVariable(“id”)
这里使用spring内置的model传递参数到view,在页面上可以采用如下语句获取数据实体内容。
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>User Show</title> </head> <body> <div> <p> <span>${user.getId()}</span> </p> <p> <strong>Name</strong> <span>${user.getName()}</span> </p> <p> <strong>Age</strong> <span>${user.getAge()}</span> </p> </div> </body> </html>
insert一个数据实体
add的get方法
@RequestMapping(value = "/add", method = RequestMethod.GET ) public String Insert() { return "add"; }
add的post方法
@RequestMapping(value = "/add", method = RequestMethod.POST ) @ResponseBody public String Insert(User u) { _userMapper.insert(u); return "insert a new user"; }
对应的view
<form action="" method="post"> <div> <p> <input type="text" value="${user.getId()}" name="id" /> </p> <p> <strong>Name</strong> <input type="text" value="${user.getName()}" name="name" /> </p> <p> <strong>Age</strong> <input type="text" value="${user.getAge()}" name="age" /> </p> </div> <div> <input type="submit" value="Submit" /> </div> </form>
其他update和delete操作和上面基本类似,至此一个简单的单表CRUD程序已经能run起来了。