2020-03-2016:24:48尚筹网项目第一天

【本笔记大多来源于封捷老师写的笔记】

尚硅谷尚筹网项目视频教程
下载链接：https://pan.baidu.com/s/1WOLG7b4yHkQfSMu3fMsOBA 
提取码：s5gw

项目概述：

一个金融类项目

项目背景：

略

后台环境搭建：

 

添加内容：

idea中创建web项目

①创建maven项目，打包方式为war

②pom文件：

<?xml version="1.0" encoding="UTF-8"?>
<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.atguigu.crowd</groupId>
    <artifactId>extra01-ajax</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <dependencies>
        <!-- SpringMVC 环境 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.3.20.RELEASE</version>
        </dependency>
        <!-- Spring 进行 JSON 数据转换依赖 -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.8</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.8</version>
        </dependency>
        <!-- 引入 Servlet 容器中相关依赖 -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
            <scope>provided</scope>
        </dependency>
        <!-- JSP 页面使用的依赖 -->
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.1.3-b06</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>


</project>

③创建web.xml文件

④改变classes文件的路径：

⑤编写web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
          http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
           version="2.5">

    <!-- 配置 CharacterEncodingFilter 解决 POST 请求的字符乱码问题 -->
    <filter>
        <filter-name>CharacterEncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <!-- 指定字符集 -->
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
        <!-- 强制请求进行编码 -->
        <init-param>
            <param-name>forceRequestEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
        <!-- 强制响应进行编码 -->
        <init-param>
            <param-name>forceResponseEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <!-- 配置 SpringMVC 的前端控制器 -->
    <!-- The front controller of this Spring Web application, responsible for handling all application requests -->
    <servlet>
        <servlet-name>springDispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
        <!-- 以初始化参数的形式指定 SpringMVC 配置文件的位置 -->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring-web-mvc.xml</param-value>
        </init-param>
        <!-- 让 DispatcherServlet 在 Web 应用启动时创建对象、初始化 -->
        <!-- 默认情况：Servlet 在第一次请求的时候创建对象、初始化 -->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <!-- Map all requests to the DispatcherServlet for handling -->
    <servlet-mapping>
        <servlet-name>springDispatcherServlet
        </servlet-name>
        <!-- DispatcherServlet 映射的 URL 地址 --> <!-- 大白话：什么样的访问地址会交给 SpringMVC 来处理 -->
        <!-- 配置方式一：符合 RESTFUL 风格使用“/” -->
        <!-- <url-pattern>/</url-pattern> -->
        <!-- 配置方式二：请求扩展名 -->
        <url-pattern>*.html</url-pattern>
        <url-pattern>*.json</url-pattern>
    </servlet-mapping>
    
</web-app>

⑥、编写springmvc的配置文件：

<?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:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">


    <!-- 配置自动扫描的包 -->
    <context:component-scan
            base-package="com.atguigu.crowd.mvc"/>
    <!-- 配置视图解析器 -->
    <!-- 拼接公式→前缀+逻辑视图+后缀=物理视图 -->
    <!--
    @RequestMapping("/xxx/xxx")
    public String xxx() {
        // 这个返回值就是逻辑视图
        return "target";
    }
    物理视图是一个可以直接转发过去的地址
    物理视图："/WEB-INF/"+"target"+".jsp"
    转发路径："/WEB-INF/target.jsp" -->
    <bean id="viewResolver"
          class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <!-- 前缀：附加到逻辑视图名称前 -->
        <property name="prefix" value="/WEB-INF/"/> <!-- 后缀：附加到逻辑视图名称后 -->
        <property name="suffix" value=".jsp"/>
    </bean>

    <!-- 启用注解驱动 -->
    <mvc:annotation-driven/>

</beans>

⑦编写handler

package com.atguigu.crowd.mvc;


import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class TestHandler {

    @RequestMapping("/test/page.html")
    public String test(){
        return "target";
    }
}

⑧编写jsp页面：

<%--
  Created by IntelliJ IDEA.
  User: 25017
  Date: 2020/3/20
  Time: 23:21
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>搭建环境，测试页面</title>
</head>
<body>

<h1>测试</h1>
</body>
</html>

⑨将项目发布到tomcat

⑩测试

http://localhost:8080/ajaxTest/test/page.html

 

1、mybatis逆向工程的使用

 maven命令：

mybatis-generator:generate

generatorConfig.xml文件，文件位置：resource目录下

<!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration> <!-- mybatis-generator:generate -->
    <context id="atguiguTables" targetRuntime="MyBatis3">
        <commentGenerator>
            <!-- 是否去除自动生成的注释 true:是;false:否 -->
            <property name="suppressAllComments" value="true"/>
        </commentGenerator>
        <!--数据库连接的信息：驱动类、连接地址、用户名、密码 -->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/project_crowd"
                        userId="root"
                        password="630415"></jdbcConnection>
        <!-- 默认 false，把 JDBC DECIMAL 和 NUMERIC 类型解析为 Integer，为 true 时把 JDBC DECIMAL和 NUMERIC 类型解析为 java.math.BigDecimal -->
        <javaTypeResolver>
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>
        <!-- targetProject:生成 Entity 类的路径 -->
        <javaModelGenerator targetProject=".\src\main\java"
                            targetPackage="com.atguigu.crowd.entity">
            <!-- enableSubPackages:是否让 schema 作为包的后缀 -->
            <property name="enableSubPackages" value="false"/>
            <!-- 从数据库返回的值被清理前后的空格 -->
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>
        <!-- targetProject:XxxMapper.xml 映射文件生成的路径 -->
        <sqlMapGenerator targetProject=".\src\main\java"
                         targetPackage="com.atguigu.crowd.mapper">
            <!-- enableSubPackages:是否让 schema 作为包的后缀 -->
            <property name="enableSubPackages" value="false"/>
        </sqlMapGenerator>
        <!-- targetPackage：Mapper 接口生成的位置 -->
        <javaClientGenerator type="XMLMAPPER" targetProject=".\src\main\java"
                             targetPackage="com.atguigu.crowd.mapper">
            <!-- enableSubPackages:是否让 schema 作为包的后缀 -->
            <property name="enableSubPackages" value="false"/>
        </javaClientGenerator>
        <!-- 数据库表名字和我们的 entity 类对应的映射指定 -->
        <table tableName="t_admin" domainObjectName="Admin"/>
    </context>
</generatorConfiguration>

pom文件：

<?xml version="1.0" encoding="UTF-8"?>

<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.atguigu.crowd</groupId>
    <artifactId>atcrowdfunding01-admin-parent</artifactId>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>atcrowdfunding02adminwebui</module>
        <module>atcrowdfunding03admincomponent</module>
        <module>atcrowdfunding04adminentity</module>
    </modules>
    <packaging>pom</packaging>

    <properties>
        <!-- 声明属性，对 Spring 的版本进行统一管理 -->
        <atguigu.spring.version>4.3.20.RELEASE</atguigu.spring.version>
        <!-- 声明属性，对 SpringSecurity 的版本进行统一管理 -->
        <atguigu.spring.security.version>4.2.10.RELEASE</atguigu.spring.security.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencyManagement>
        <dependencies>
            <!-- Spring 依赖 --> <!-- https://mvnrepository.com/artifact/org.springframework/spring-orm -->
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-orm</artifactId>
                <version>${atguigu.spring.version}</version>
            </dependency>
            <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-webmvc</artifactId>
                <version>${atguigu.spring.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-test</artifactId>
                <version>${atguigu.spring.version}</version>
            </dependency>
            <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
            <dependency>
                <groupId>org.aspectj</groupId>
                <artifactId>aspectjweaver</artifactId>
                <version>1.9.2</version>
            </dependency>
            <!-- https://mvnrepository.com/artifact/cglib/cglib -->
            <dependency>
                <groupId>cglib</groupId>
                <artifactId>cglib</artifactId>
                <version>2.2</version>
            </dependency>
            <!-- 数据库依赖 --> <!-- MySQL 驱动 -->
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.3</version>
            </dependency>
            <!-- 数据源 -->
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid</artifactId>
                <version>1.0.31</version>
            </dependency>
            <!-- MyBatis -->
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis</artifactId>
                <version>3.2.8</version>
            </dependency>
            <!-- MyBatis 与 Spring 整合 -->
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis-spring</artifactId>
                <version>1.2.2</version>
            </dependency>
            <!-- MyBatis 分页插件 -->
            <dependency>
                <groupId>com.github.pagehelper</groupId>
                <artifactId>pagehelper</artifactId>
                <version>4.0.0</version>
            </dependency>
            <!-- 日志 -->
            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-api</artifactId>
                <version>1.7.7</version>
            </dependency>
            <dependency>
                <groupId>ch.qos.logback</groupId>
                <artifactId>logback-classic</artifactId>
                <version>1.2.3</version>
            </dependency>
            <!-- 其他日志框架的中间转换包 -->
            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>jcl-over-slf4j</artifactId>
                <version>1.7.25</version>
            </dependency>
            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>jul-to-slf4j</artifactId>
                <version>1.7.25</version>
            </dependency>
            <!-- Spring 进行 JSON 数据转换依赖 -->
            <dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-core</artifactId>
                <version>2.9.8</version>
            </dependency>
            <dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-databind</artifactId>
                <version>2.9.8</version>
            </dependency>
            <!-- JSTL 标签库 -->
            <dependency>
                <groupId>jstl</groupId>
                <artifactId>jstl</artifactId>
                <version>1.2</version>
            </dependency>
            <!-- junit 测试 -->
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
                <scope>test</scope>
            </dependency>
            <!-- 引入 Servlet 容器中相关依赖 -->
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>servlet-api</artifactId>
                <version>2.5</version>
                <scope>provided</scope>
            </dependency>
            <!-- JSP 页面使用的依赖 -->
            <dependency>
                <groupId>javax.servlet.jsp</groupId>
                <artifactId>jsp-api</artifactId>
                <version>2.1.3-b06</version>
                <scope>provided</scope>
            </dependency>
            <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
            <dependency>
                <groupId>com.google.code.gson</groupId>
                <artifactId>gson</artifactId>
                <version>2.8.5</version>
            </dependency>
            <!-- SpringSecurity 对 Web 应用进行权限管理 -->
            <dependency>
                <groupId>org.springframework.security</groupId>
                <artifactId>spring-security-web</artifactId>
                <version>4.2.10.RELEASE</version>
            </dependency>
            <!-- SpringSecurity 配置 -->
            <dependency>
                <groupId>org.springframework.security</groupId>
                <artifactId>spring-security-config</artifactId>
                <version>4.2.10.RELEASE</version>
            </dependency>
            <!-- SpringSecurity 标签库 -->
            <dependency>
                <groupId>org.springframework.security</groupId>
                <artifactId>spring-security-taglibs</artifactId>
                <version>4.2.10.RELEASE</version>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
            <plugins>
                <plugin>
                    <artifactId>maven-clean-plugin</artifactId>
                    <version>3.1.0</version>
                </plugin>
                <plugin>
                    <artifactId>maven-site-plugin</artifactId>
                    <version>3.7.1</version>
                </plugin>
                <plugin>
                    <artifactId>maven-project-info-reports-plugin</artifactId>
                    <version>3.0.0</version>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>

    <reporting>
        <plugins>
            <plugin>
                <artifactId>maven-project-info-reports-plugin</artifactId>
            </plugin>
        </plugins>
    </reporting>
</project>

2、spring整合mybatis

pom依赖：

<?xml version="1.0" encoding="UTF-8"?>
<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">
    <parent>
        <artifactId>atcrowdfunding01-admin-parent</artifactId>
        <groupId>com.atguigu.crowd</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>atcrowdfunding02-admin-webui</artifactId>
    <packaging>war</packaging>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
        </dependency>
        <dependency>
            <groupId>com.atguigu.crowd</groupId>
            <artifactId>atcrowdfunding03-admin-component</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

        <!-- 引入 Servlet 容器中相关依赖 -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <scope>provided</scope>
        </dependency>
        <!-- JSP 页面使用的依赖 -->
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <scope>provided</scope>
        </dependency>
    </dependencies>

</project>

jdbc.properties

jdbc.user=root
jdbc.password=630415
jdbc.url=jdbc:mysql://localhost:3306/project_crowd?useUnicode=true&characterEncoding=UTF-8
jdbc.driver=com.mysql.jdbc.Driver

spring整合mybatis的配置文件

<?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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">

    <!-- 加载 jdbc.properties -->
    <context:property-placeholder location="classpath:jdbc.properties"/>

    <!-- 配置数据源 -->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <!-- 连接数据库的用户名 -->
        <property name="username" value="${jdbc.user}"/>
        <!-- 连接数据库的密码 -->
        <property name="password" value="${jdbc.password}"/>
        <!-- 目标数据库的 URL 地址 -->
        <property name="url" value="${jdbc.url}"/>
        <!-- 数据库驱动全类名 -->
        <property name="driverClassName" value="${jdbc.driver}"/>

    </bean>

    <!-- 配置 SqlSessionFactoryBean -->
    <bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean"> <!-- 装配数据源 -->
        <property name="dataSource" ref="dataSource"/> <!-- 指定 MyBatis 全局配置文件位置 -->
        <property name="configLocation" value="classpath:mybatis/mybatis-config.xml"/> <!-- 指定 Mapper 配置文件位置 -->
        <property name="mapperLocations" value="classpath:mybatis/mapper/*Mapper.xml"/>
    </bean>

    <!-- 配置 MapperScannerConfigurer -->
    <!-- 把 MyBatis 创建的 Mapper 接口类型的代理对象扫描到 IOC 容器中 -->
    <bean id="mapperScannerConfigurer"
          class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!-- 使用 basePackage 属性指定 Mapper 接口所在包 -->
        <property name="basePackage" value="com.atguigu.crowd.mapper"/>
    </bean>


</beans>

mybatis全局配置文件：

<?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>


</configuration>

测试数据源、spring和mybatis整合【需要将service包进行扫描】

package com.atguigu.crowd.test;


import com.atguigu.crowd.entity.Admin;
import com.atguigu.crowd.service.AdmainService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;

// 指定 Spring 给 Junit 提供的运行器类
@RunWith(SpringJUnit4ClassRunner.class)
// 加载 Spring 配置文件的注解
@ContextConfiguration(locations = {"classpath:spring-persist-mybatis.xml", "classpath:spring-persist-tx.xml"})
public class CrowdSpringTest {

    @Autowired
    private DataSource dataSource;

    @Autowired
    private AdmainService admainService;

    @Test
    public void testDataSource(){

        try {
            Connection connection = dataSource.getConnection();
            System.out.println(connection+"....");

        } catch (SQLException e) {
            e.printStackTrace();
        }

    }


    @Test
    public void testSpringAndMybatis(){
        Admin admin = admainService.queryById(1);
        System.out.println(admin+"...");

        // 获取日志记录对象
        Logger logger = LoggerFactory.getLogger(CrowdSpringTest.class);
        // 按照 Debug 级别打印日志
        logger.debug(admin.toString());

    }
}

3、日志系统

logback.xml

使用slf4j作为日志门面，使用logback作为日志实现，需要将logging

<?xml version="1.0" encoding="UTF-8"?>
<configuration debug="true">
    <!-- 指定日志输出的位置 -->
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <!-- 日志输出的格式 -->
            <!-- 按照顺序分别是：时间、日志级别、线程名称、打印日志的类、日志主体 内容、换行 -->
            <pattern>[%d{HH:mm:ss.SSS}] [%-5level] [%thread] [%logger] [%msg]%n</pattern>
        </encoder>
    </appender>
    <!-- 设置全局日志级别。日志级别按顺序分别是：DEBUG、INFO、WARN、ERROR -->
    <!-- 指定任何一个日志级别都只打印当前级别和后面级别的日志。 -->
    <root level="INFO">
        <!-- 指定打印日志的 appender，这里通过“STDOUT”引用了前面配置的 appender -->
        <appender-ref ref="STDOUT"/>
    </root>
    <!-- 根据特殊需求指定局部日志级别 -->
    <logger name="com.atguigu.crowd.mapper" level="DEBUG"/>
</configuration>

pom文件：

<?xml version="1.0" encoding="UTF-8"?>
<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">
    <parent>
        <artifactId>atcrowdfunding01-admin-parent</artifactId>
        <groupId>com.atguigu.crowd</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>atcrowdfunding03-admin-component</artifactId>

    <dependencies>

        <!-- 引入Servlet容器中相关依赖 -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.atguigu.crowd</groupId>
            <artifactId>atcrowdfunding05-common-util</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

        <dependency>
            <groupId>com.atguigu.crowd</groupId>
            <artifactId>atcrowdfunding04-admin-entity</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <!-- Spring 依赖 -->
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-orm -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <exclusions>
                <exclusion>
                    <artifactId>commons-logging</artifactId>
                    <groupId>commons-logging</groupId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
        </dependency>

        <!-- aop相关的依赖-->
        <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
        </dependency>
        <!-- https://mvnrepository.com/artifact/cglib/cglib -->
        <dependency>
            <groupId>cglib</groupId>
            <artifactId>cglib</artifactId>
        </dependency>
        <!-- MySQL 驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!-- 数据源 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
        </dependency>
        <!-- MyBatis -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
        </dependency>
        <!-- MyBatis 与 Spring 整合 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
        </dependency>
        <!-- MyBatis 分页插件 -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
        </dependency>
        <!-- Spring 进行 JSON 数据转换依赖 -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
        </dependency>
        <!-- JSTL 标签库 -->
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
        </dependency>

        <!-- 测试相关的依赖 -->
        <!-- junit 测试 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${atguigu.spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.7</version>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
        </dependency>

        <!-- 排除commons-logging需要添加的转换包 -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jcl-over-slf4j</artifactId>
            <version>1.7.25</version>
        </dependency>

    </dependencies>

</project>

4、声明式事务的配置

配置文件：

<?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:tx="http://www.springframework.org/schema/tx"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">

    <!-- 扫描业务逻辑层 -->
    <context:component-scan base-package="com.atguigu.crowd.service"/>

    <!-- 配置事务管理器 -->
    <bean id="dataSourceTransactionManager"
          class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <!-- 装配数据源 -->
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <!-- 配置 AOP -->
    <aop:config> <!-- 配置切入点表达式 --> <!-- public String com.atguigu.crowd.service.AdminService.getXxx(Integer id) -->
        <aop:pointcut expression="execution(* *..*Service.*(..))" id="txPointCut"/> <!-- 将事务通知和切入点表达式关联到一起 -->
        <aop:advisor advice-ref="txAdvice" pointcut-ref="txPointCut"/>
    </aop:config>

    <!-- 配置事务通知 -->
    <!-- id 属性用于在 aop:advisor 中引用事务通知 -->
    <!-- transaction-manager 属性用于引用事务管理器，如果事务管理器的 bean 的 id 正好是 transactionManager，可以省略这个属性 -->
    <tx:advice id="txAdvice" transaction-manager="dataSourceTransactionManager">
        <tx:attributes>
            <!-- name 属性指定当前要配置的事务方法的方法名 -->
            <!-- 查询的方法通常设置为只读，便于数据库根据只读属性进行相关性能优化 -->
            <tx:method name="get*" read-only="true"/>
            <tx:method name="query*" read-only="true"/>
            <tx:method name="find*" read-only="true"/>
            <tx:method name="count*"
                       read-only="true"/>
            <!-- 增删改方法另外配置 -->
            <!-- propagation 属性配置事务方法的传播行为 -->
            <!-- 默认值：REQUIRED 表示：当前方法必须运行在事务中，如果没有事务，则开 启事务，在自己的事务中运行。如果已经有了已开启的事务，则在当前事务中运行。有可能 和其他方法共用同一个事务。 -->
            <!-- 建议值：REQUIRES_NEW 表示：当前方法必须运行在事务中，如果没有事务， 则开启事务，在自己的事务中运行。和 REQUIRED 的区别是就算现在已经有了已开启的事务， 也一定要开启自己的事务，避免和其他方法共用同一个事务。 -->
            <!-- rollback-for 属性配置回滚的异常 -->
            <!-- 默认值：运行时异常 -->
            <!-- 建议值：编译时异常+运行时异常 -->
            <tx:method name="save*" propagation="REQUIRES_NEW" rollback-for="java.lang.Exception"/>
            <tx:method name="remove*" propagation="REQUIRES_NEW" rollback-for="java.lang.Exception"/>
            <tx:method name="update*" propagation="REQUIRES_NEW" rollback-for="java.lang.Exception"/>
        </tx:attributes>
    </tx:advice>

</beans>

5、表述层环境的搭建

springmvc的配置：

<?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:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">


    <!-- 配置自动扫描的包 -->
    <context:component-scan
            base-package="com.atguigu.crowd.mvc"/>
    <!-- 配置视图解析器 -->
    <!-- 拼接公式→前缀+逻辑视图+后缀=物理视图 -->
    <!--
    @RequestMapping("/xxx/xxx")
    public String xxx() {
        // 这个返回值就是逻辑视图
        return "target";
    }
    物理视图是一个可以直接转发过去的地址
    物理视图："/WEB-INF/"+"target"+".jsp"
    转发路径："/WEB-INF/target.jsp" -->
    <bean id="viewResolver"
          class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <!-- 前缀：附加到逻辑视图名称前 -->
        <property name="prefix" value="/WEB-INF/"/> <!-- 后缀：附加到逻辑视图名称后 -->
        <property name="suffix" value=".jsp"/>
    </bean>

    <!-- 启用注解驱动 -->
    <mvc:annotation-driven/>

</beans>

web.xml配置：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
          http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
         version="2.5">

    <!-- 配置 ContextLoaderListener 加载 Spring 配置文件 --> <!-- needed for ContextLoaderListener -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring-persist-*.xml</param-value>
    </context-param>


    <!-- Bootstraps the root web application context before servlet initialization -->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <!-- 配置 CharacterEncodingFilter 解决 POST 请求的字符乱码问题 -->
    <filter>
        <filter-name>CharacterEncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <!-- 指定字符集 -->
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
        <!-- 强制请求进行编码 -->
        <init-param>
            <param-name>forceRequestEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
        <!-- 强制响应进行编码 -->
        <init-param>
            <param-name>forceResponseEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <!-- 配置 SpringMVC 的前端控制器 -->
    <!-- The front controller of this Spring Web application, responsible for handling all application requests -->
    <servlet>
        <servlet-name>springDispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
        <!-- 以初始化参数的形式指定 SpringMVC 配置文件的位置 -->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring-web-mvc.xml</param-value>
        </init-param>
        <!-- 让 DispatcherServlet 在 Web 应用启动时创建对象、初始化 -->
        <!-- 默认情况：Servlet 在第一次请求的时候创建对象、初始化 -->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <!-- Map all requests to the DispatcherServlet for handling -->
    <servlet-mapping>
        <servlet-name>springDispatcherServlet
        </servlet-name>
        <!-- DispatcherServlet 映射的 URL 地址 --> <!-- 大白话：什么样的访问地址会交给 SpringMVC 来处理 -->
        <!-- 配置方式一：符合 RESTFUL 风格使用“/” -->
        <!-- <url-pattern>/</url-pattern> -->
        <!-- 配置方式二：请求扩展名 -->
        <url-pattern>*.html</url-pattern>
        <url-pattern>*.json</url-pattern>
    </servlet-mapping>
</web-app>

6、ajax测试

传输数组的三种方式：

方式一：

页面：

<button id="btn1">测试发送数组[5,8,12]方式1</button>
需要将下面的代码放在文档就绪函数里：
//文档就绪函数
$(function(){
//this

}）；
$("#btn1").click(function(){
                $.ajax({
                    "url": "test/array/one.json",
                    "type": "post",
                    "data":{
                        "empIdArray":[5,8,12]
                    },
                    //"contentType":"application/json;charset=UTF-8",
                    "dataType":"json",
                    "success":function(response){
                        alert(response);
                    }
                });
            });

后台：

方式一：
@ResponseBody
    @RequestMapping("/test/array/one")
    public Employee testArrayOne(@RequestParam("empIdArray[]") Integer[] empIdArray){
        String temp = "";
        if(empIdArray != null){
            for (int i=0,length = empIdArray.length;i<length;i++){
                temp += empIdArray[i];
                System.out.println("one:"+temp);
            }
        }


        return new Employee("张三","男","zs@qq.com"+temp);
    }

方式二：

页面：

<button id="btn2">测试发送数组[5,8,12]方式2</button>
$("#btn2").click(function(){
                $.ajax({
                    "url": "test/array/two.json",
                    "type": "post",
                    "data":{
                        "empIdArray[0]":5,
                        "empIdArray[1]":8,
                        "empIdArray[2]":12
                    },
                    //"contentType":"application/json;charset=UTF-8",
                    "dataType":"json",
                    "success":function(response){
                        alert(response);
                    }
                });
            });

后台：

@ResponseBody
    @RequestMapping("/test/array/two")
    public Employee testArrayTwo(ParamData paramData){
        Integer[] empIdArray = paramData.getEmpIdArray();
        String temp = "";
        if(empIdArray != null){
            for (int i=0,length = empIdArray.length;i<length;i++){
                temp += empIdArray[i];
                System.out.println("two:"+temp);
            }
        }

        return new Employee("张三","男","zs@qq.com"+temp);
    }

package com.atguigu.crowd.entity;

public class ParamData {
    private Integer[] empIdArray;

    public void setEmpIdArray(Integer[] empIdArray) {
        this.empIdArray = empIdArray;
    }

    public Integer[] getEmpIdArray() {
        return empIdArray;
    }
}

方式三：

页面：

<button id="btn3">测试发送数组[5,8,12]方式3</button>
$("#btn3").click(function(){
                // 准备好要发送到服务器端的数组
                var array = [5, 8, 12];
                console.log(array.length);

                // 将JSON数组转换为JSON字符串
                var requestBody = JSON.stringify(array);
                // "['5','8','12']"
                console.log(requestBody.length);
                $.ajax({
                    "url": "test/array/three.json",// 请求目标资源的地址
                    "type": "post",                        // 请求方式
                    "data": requestBody,                // 请求体
                    "contentType": "application/json;charset=UTF-8",    // 设置请求体的内容类型，告诉服务器端本次请求的请求体是JSON数据
                    "dataType": "text",                    // 如何对待服务器端返回的数据
                    "success": function(response) {        // 服务器端成功处理请求后调用的回调函数，response是响应体数据
                        alert(response);
                    },
                    "error":function(response) {        // 服务器端处理请求失败后调用的回调函数，response是响应体数据
                        alert(response);
                    }
                });
            });

后台：

@ResponseBody
    @RequestMapping("/test/array/three")
    public Employee testArrayThree(@RequestBody Integer[] array1){

        String temp = "";
        for (int i=0,length = array1.length;i<length;i++){
            temp += array1[i];
            System.out.println("three:"+temp);
        }


        return new Employee("张三","男","zs@qq.com"+temp);
    }

传输复杂类型：

页面：

<button id="btn4">提交复杂参数student【list、map、对象】</button>
$("#btn4").click(function(){

                // 准备要发送的数据
                var student = {
                    "stuId": 5,
                    "stuName":"tom",
                    "address": {
                        "province": "广东",
                        "city": "深圳",
                        "street":"后瑞"
                    },
                    "subjectList": [
                        {
                            "subjectName": "JavaSE",
                            "subjectScore": 100
                        },{
                            "subjectName": "SSM",
                            "subjectScore": 99
                        }
                    ],
                    "map": {
                        "k1":"v1",
                        "k2":"v2"
                    }
                };

                // 将JSON对象转换为JSON字符串
                var requestBody = JSON.stringify(student);

                // 发送Ajax请求
                $.ajax({
                    "url":"test/student.json",
                    "type":"post",
                    "data":requestBody,
                    "contentType":"application/json;charset=UTF-8",
                    "dataType":"json",
                    "success":function(response){
                        console.log(response);
                    },
                    "error":function(response){
                        console.log(response);
                    }
                });

            });

后台：

package com.atguigu.crowd.entity;

import java.util.List;
import java.util.Map;

public class Student {

    private Integer stuId;
    private String stuName;
    private Address address;
    private List<Subject> subjectList;
    private Map<String,String> map;

    @Override
    public String toString() {
        return "Student{" +
                "stuId=" + stuId +
                ", stuName='" + stuName + '\'' +
                ", address=" + address +
                ", subjectList=" + subjectList +
                ", map=" + map +
                '}';
    }

    public Integer getStuId() {
        return stuId;
    }

    public void setStuId(Integer stuId) {
        this.stuId = stuId;
    }

    public String getStuName() {
        return stuName;
    }

    public void setStuName(String stuName) {
        this.stuName = stuName;
    }

    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }

    public List<Subject> getSubjectList() {
        return subjectList;
    }

    public void setSubjectList(List<Subject> subjectList) {
        this.subjectList = subjectList;
    }

    public Map<String, String> getMap() {
        return map;
    }

    public void setMap(Map<String, String> map) {
        this.map = map;
    }
}

package com.atguigu.crowd.entity;

public class Subject {
    private String subjectName;
    private String subjectScore;

    @Override
    public String toString() {
        return "Subject{" +
                "subjectName='" + subjectName + '\'' +
                ", subjectScore='" + subjectScore + '\'' +
                '}';
    }

    public String getSubjectName() {
        return subjectName;
    }

    public void setSubjectName(String subjectName) {
        this.subjectName = subjectName;
    }

    public String getSubjectScore() {
        return subjectScore;
    }

    public void setSubjectScore(String subjectScore) {
        this.subjectScore = subjectScore;
    }
}

package com.atguigu.crowd.entity;

public class Address {
    private String province;
    private String city;
    private String street;

    @Override
    public String toString() {
        return "Address{" +
                "province='" + province + '\'' +
                ", city='" + city + '\'' +
                ", street='" + street + '\'' +
                '}';
    }

    public String getProvince() {
        return province;
    }

    public void setProvince(String province) {
        this.province = province;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getStreet() {
        return street;
    }

    public void setStreet(String street) {
        this.street = street;
    }
}

@ResponseBody
    @RequestMapping("/test/student")
    public Student testStudent(@RequestBody Student student){

        System.out.println("查看封装的student对象：");
        System.out.println(student);


        return student;
    }

7、统一的返回

pom：

<?xml version="1.0" encoding="UTF-8"?>
<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.atguigu.crowd</groupId>
    <artifactId>atcrowdfunding05-common-util</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <!-- 引入Servlet容器中相关依赖 -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>

</project>

代码：

package com.atguigu.crowd.util;

/**
 * 统一整个项目中Ajax请求返回的结果（未来也可以用于分布式架构各个模块间调用时返回统一类型）
 * @author Lenovo
 *
 * @param <T>
 */
public class ResultEntity<T> {
    
    public static final String SUCCESS = "SUCCESS";
    public static final String FAILED = "FAILED";
    
    // 用来封装当前请求处理的结果是成功还是失败
    private String result;
    
    // 请求处理失败时返回的错误消息
    private String message;
    
    // 要返回的数据
    private T data;
    
    /**
     * 请求处理成功且不需要返回数据时使用的工具方法
     * @return
     */
    public static <Type> ResultEntity<Type> successWithoutData() {
        return new ResultEntity<Type>(SUCCESS, null, null);
    }
    
    /**
     * 请求处理成功且需要返回数据时使用的工具方法
     * @param data 要返回的数据
     * @return
     */
    public static <Type> ResultEntity<Type> successWithData(Type data) {
        return new ResultEntity<Type>(SUCCESS, null, data);
    }
    
    /**
     * 请求处理失败后使用的工具方法
     * @param message 失败的错误消息
     * @return
     */
    public static <Type> ResultEntity<Type> failed(String message) {
        return new ResultEntity<Type>(FAILED, message, null);
    }
    
    public ResultEntity() {
        
    }

    public ResultEntity(String result, String message, T data) {
        super();
        this.result = result;
        this.message = message;
        this.data = data;
    }

    @Override
    public String toString() {
        return "ResultEntity [result=" + result + ", message=" + message + ", data=" + data + "]";
    }

    public String getResult() {
        return result;
    }

    public void setResult(String result) {
        this.result = result;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public T getData() {
        return data;
    }

    public void setData(T data) {
        this.data = data;
    }

}

8、异常映射

基于配置文件：

springmvc的xml新增：

<!-- 配置基于 XML 的异常映射 -->
    <bean id="simpleMappingExceptionResolver"
          class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
        <!-- 指定异常类型和逻辑视图名称的对应关系 -->
        <property name="exceptionMappings">
            <props>
                <!-- key 属性指定异常类型（全类名） -->
                <!-- 文本标签体中指定异常对应的逻辑视图名称 -->
                <prop key="java.lang.NullPointerException">system-error</prop>
            </props>
        </property>
        <!-- 使用 exceptionAttribute 可以修改异常对象存入请求域时使用的属性名 -->
        <!-- <property name="exceptionAttribute"></property> -->
    </bean>

pom文件：

<?xml version="1.0" encoding="UTF-8"?>
<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">
    <parent>
        <artifactId>atcrowdfunding01-admin-parent</artifactId>
        <groupId>com.atguigu.crowd</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>atcrowdfunding02-admin-webui</artifactId>
    <packaging>war</packaging>

    <dependencies>

        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.5</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
        </dependency>
        <dependency>
            <groupId>com.atguigu.crowd</groupId>
            <artifactId>atcrowdfunding03-admin-component</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>


        <!-- 引入 Servlet 容器中相关依赖 -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <scope>provided</scope>
        </dependency>
        <!-- JSP 页面使用的依赖 -->
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <scope>provided</scope>
        </dependency>
    </dependencies>

</project>

基于注解：

springmvc的xml新增：

<!-- 启用注解驱动 -->
    <mvc:annotation-driven/>

判断请求是否为ajax：

package com.atguigu.crowd.util;

import javax.servlet.http.HttpServletRequest;

public class CrowdUtil {
    
    /**
     * 判断当前请求是否为Ajax请求
     * @param request 请求对象
     * @return
     *         true：当前请求是Ajax请求
     *         false：当前请求不是Ajax请求
     */
    public static boolean judgeRequestType(HttpServletRequest request) {
        
        // 1.获取请求消息头
        String acceptHeader = request.getHeader("Accept");
        String xRequestHeader = request.getHeader("X-Requested-With");
        
        // 2.判断
        return (acceptHeader != null && acceptHeader.contains("application/json"))
                
                ||
                
                (xRequestHeader != null && xRequestHeader.equals("XMLHttpRequest"));
    }

}

异常处理的代码：

package com.atguigu.crowd.mvc.config;


import com.atguigu.crowd.util.CrowdUtil;
import com.atguigu.crowd.util.ResultEntity;
import com.google.gson.Gson;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@ControllerAdvice
public class CrowdExceptionResolver {

    @ExceptionHandler(value = ArithmeticException.class)
    public ModelAndView resolveMathException(
            ArithmeticException exception,
            HttpServletRequest request,
            HttpServletResponse response
    ) throws IOException {

        String viewName = "system-error";

        return commonResolve(viewName, exception, request, response);
    }
    @ExceptionHandler(value = NullPointerException.class)
    public ModelAndView resolveNullPointerException(
            NullPointerException exception,
            HttpServletRequest request,
            HttpServletResponse response) throws IOException {

        String viewName = "system-error";

        return commonResolve(viewName, exception, request, response);
    }


    // @ExceptionHandler将一个具体的异常类型和一个方法关联起来
    private ModelAndView commonResolve(

            // 异常处理完成后要去的页面
            String viewName,

            // 实际捕获到的异常类型
            Exception exception,

            // 当前请求对象
            HttpServletRequest request,

            // 当前响应对象
            HttpServletResponse response) throws IOException {

        // 1.判断当前请求类型
        boolean judgeResult = CrowdUtil.judgeRequestType(request);

        // 2.如果是Ajax请求
        if(judgeResult) {

            // 3.创建ResultEntity对象
            ResultEntity<Object> resultEntity = ResultEntity.failed(exception.getMessage());

            // 4.创建Gson对象
            Gson gson = new Gson();

            // 5.将ResultEntity对象转换为JSON字符串
            String json = gson.toJson(resultEntity);

            // 6.将JSON字符串作为响应体返回给浏览器
            response.getWriter().write(json);

            // 7.由于上面已经通过原生的response对象返回了响应，所以不提供ModelAndView对象
            return null;
        }

        // 8.如果不是Ajax请求则创建ModelAndView对象
        ModelAndView modelAndView = new ModelAndView();

        // 9.将Exception对象存入模型
        modelAndView.addObject("exception", exception);

        // 10.设置对应的视图名称
        modelAndView.setViewName(viewName);

        // 11.返回modelAndView对象
        return modelAndView;
    }
}