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Spring+SpringMVC+MyBatis 整合

编辑：016     时间：2020-02-11

spring+SpringMVC+MyBatis（SSM）在我们项目中是经常用到的，这篇文章主要讲解使用Intellij IDEA整合SSM，具体环境如下：

  • 数据库：MySQL5.7
  • 依赖管理：Maven
  • IDE：Intellij IDEA
  • JDK：1.8
  • 服务器：Tomcat 9

首先用Intellij IDEA创建Maven项目，如果还不知道怎么创建的朋友可以先去百度谷歌，网上很多这种教程，这里我主要讲解SSM整合的过程，项目目录结构如下：

1.创建表，插入数据 

CREATE TABLE user (
  id INTEGER PRIMARY KEY AUTO_INCREMENT,
  name CHAR(20) NOT NULL,
  password CHAR(40) NOT NULL )
  ENGINE = InnoDB
  AUTO_INCREMENT = 16 DEFAULT CHARSET = utf8;
INSERT INTO user (id,name, password) VALUES (1,'A', '123'); INSERT INTO user (id,name, password) VALUES (2,'B', '456');

2.添加Maven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"> <modelVersion>4.0.0</modelVersion> <groupId>com.demo</groupId> <artifactId>SSM</artifactId> <version>1.0-SNAPSHOT</version> <packaging>war</packaging> <name>SSM</name> <description/> <properties> <spring.version>4.3.4.RELEASE</spring.version> <mybatis.version>3.4.2</mybatis.version> <log4j.version>2.7</log4j.version> <junit.version>4.12</junit.version> <driver.version>5.1.40</driver.version> </properties> <dependencies> <!--Spring start--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>${spring.version}</version> </dependency> <!--绑定XML--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-oxm</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aspects</artifactId> <version>${spring.version}</version> </dependency> <!--Spring end--> <!--AOP start--> <dependency> <groupId>aopalliance</groupId> <artifactId>aopalliance</artifactId> <version>1.0</version> </dependency> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.8.10</version> </dependency> <!--AOP end--> <!--文件上传start--> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.2</version> </dependency> <!--文件上传end--> <!--json start--> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>2.8.4</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.8.4</version> </dependency> <!--json end--> <!--mybatis start--> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.4.2</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.3.1</version> </dependency> <!--mybatis end--> <!--log start--> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-core</artifactId> <version>${log4j.version}</version> </dependency> <!--log end--> <!--单元测试start--> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>${junit.version}</version> </dependency> <!--单元测试end--> <!--数据库驱动start--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.40</version> </dependency> <!--数据库驱动end--> <!--druid start--> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.0.29</version> </dependency> <!--druid end--> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.6.1</version> <configuration> <source>1.8</source> <target>1.8</target> </configuration> </plugin> <!--MBG--> <plugin> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-maven-plugin</artifactId> <version>1.3.5</version> <configuration> <verbose>true</verbose> <overwrite>true</overwrite> </configuration> </plugin> </plugins> </build> </project>

代码都加了注释，很容易看懂。需要说一下的是MBG，全称是MyBatis Generator，是一个生成MyBatis代码的插件，后面会用到。具体可以看看 MyBatis Generator官方文档

3.配置文件

3.1 Mybatis配置文件mybatis-config.xml 
<?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>
3.2 数据库配置文件database.properties 
db.driver=com.mysql.jdbc.Driver db.url=jdbc:mysql://localhost:3306/mybatis?characterEncoding=UTF-8 db.user=root
db.password=123456 db.maxActive=10 db.initialSize=2 db.minIdle=2 db.maxWait=60000 db.timeBetweenEvictionRunsMillis=3000 db.minEvictableIdleTimeMillis=300000 db.validationQuery=SELECT 'x' FROM DUAL
db.testWhileIdle=true
db.testOnBorrow=false
db.testOnReturn=false
3.3 Spring配置文件application.xml 
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" 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.xsd"> <import resource="classpath:spring/spring-mybatis.xml"/> </beans>

这里为了方便项目扩展，用import标签引入另一个配置文件spring-mybatis.xml 

<?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:tx="http://www.springframework.org/schema/tx" 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/tx
       http://www.springframework.org/schema/tx/spring-tx.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd"> <context:property-placeholder location="classpath:properties/database.properties"/> <!--数据源配置--> <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close"> <!--驱动--> <property name="driverClassName" value="${db.driver}"/> <!-- 数据库地址 --> <property name="url" value="${db.url}"/> <!-- 用户名 --> <property name="username" value="${db.user}"/> <!-- 密码 --> <property name="password" value="${db.password}"/> <!-- 最大连接池数量 --> <property name="maxActive" value="${db.maxActive}"/> <!-- 初始化物理连接个数 --> <property name="initialSize" value="${db.initialSize}"/> <!-- 最小连接池数量 --> <property name="minIdle" value="${db.minIdle}"/> <!-- 最大等待时间 --> <property name="maxWait" value="${db.maxWait}"/> <property name="timeBetweenEvictionRunsMillis" value="${db.timeBetweenEvictionRunsMillis}"/> <property name="minEvictableIdleTimeMillis" value="${db.minEvictableIdleTimeMillis}"/> <!-- 检测连接是否有效的SQL --> <property name="validationQuery" value="${db.validationQuery}"/> <property name="testWhileIdle" value="${db.testWhileIdle}"/> <!-- 申请连接时是否执行validationQuery --> <property name="testOnBorrow" value="${db.testOnBorrow}"/> <!-- 归还连接时是否执行validationQuery --> <property name="testOnReturn" value="${db.testOnReturn}"/> </bean> <!-- 配置Mybatis的文件 ，mapperLocations配置**Mapper.xml文件位置，configLocation配置mybatis-config文件位置--> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"/> <property name="mapperLocations" value="classpath:mapper/*.xml"/> <property name="configLocation" value="classpath:mybatis/mybatis-config.xml"/> </bean> <!-- 自动扫描了所有的XxxxMapper.xml对应的mapper接口文件，这样就不用一个一个手动配置Mpper的映射了，
           只要Mapper接口类和Mapper映射文件对应起来就可以了 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.demo.dao"/> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/> </bean> <!-- 事物管理器 --> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/> </bean> <tx:annotation-driven transaction-manager="transactionManager"/> </beans>
3.4 SpringMVC配置文件spring-mvc.xml 
<?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/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <!-- 注解的支持，可以将请求参数绑定到控制器参数--> <mvc:annotation-driven/> <!--注解扫描--> <context:component-scan base-package="com.demo.controller"/> <context:component-scan base-package="com.demo.serviceImpl"/> <!--静态资源处理，mapping：匹配URL，location：静态资源在WebApp中的位置--> <mvc:resources mapping="/common/**" location="/common/"/> <mvc:resources mapping="/css/**" location="/css/"/> <mvc:resources mapping="/image/**" location="/image/"/> <mvc:resources mapping="/js/**" location="/js/"/> <!-- 注解的映射器 --> <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"/> <!-- 注解的适配器 --> <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"/> <!-- 视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="contentType" value="text/html"/> <property name="prefix" value="/jsp/"/> <property name="suffix" value=".jsp"/> </bean> <!--上传文件配置--> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!-- 默认编码 --> <property name="defaultEncoding" value="UTF-8"/> <!-- 启用是为了推迟文件解析，以便捕获文件大小异常 --> <property name="resolveLazily" value="true"/> <!-- 文件大小最大值 --> <property name="maxUploadSize" value="209715200"/> <!-- 内存中的最大值 --> <property name="maxInMemorySize" value="40960"/> </bean> </beans>
3.5 log4j配置文件log4j.xml 
<?xml version="1.0" encoding="UTF-8"?> <Configuration status="WARN"> <Appenders> <Console name="Console" target="SYSTEM_OUT"> <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" /> </Console> </Appenders> <Loggers> <Root level="debug"> <AppenderRef ref="Console" /> </Root> </Loggers> </Configuration>
3.6 MyBatis Generator配置文件generatorConfig.xml 
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd"> <generatorConfiguration> <!--数据库驱动--> <classPathEntry  location="C:/Users/Administrator/.m2/repository/mysql/mysql-connector-java/5.1.40/mysql-connector-java-5.1.40.jar"/> <context id="mybatis" targetRuntime="MyBatis3"> <!-- 防止生成的代码中有很多注释--> <commentGenerator> <property name="suppressAllComments" value="true"/> <property name="suppressDate" value="true"/> </commentGenerator> <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/mybatis" userId="root" password="199498xy"> </jdbcConnection> <!--Java类型解析器不应该强制型对象字段BigDecimal的使用，此功能是为了使数据库DECIMAL和NUMERIC列容易处理--> <javaTypeResolver> <property name="forceBigDecimals" value="false"/> </javaTypeResolver> <!--生成Model类存放位置--> <javaModelGenerator targetPackage="com.demo.bean" targetProject="E:/workspace/java/project/SSM/src/main/java"> <property name="enableSubPackages" value="true"/> <property name="trimStrings" value="true"/> </javaModelGenerator> <!--生成映射文件存放位置--> <sqlMapGenerator targetPackage="mapper" targetProject="E:/workspace/java/project/SSM/src/main/resources"> <property name="enableSubPackages" value="true"/> </sqlMapGenerator> <!--生成Dao类存放位置--> <javaClientGenerator type="XMLMAPPER" targetPackage="com.demo.dao" targetProject="E:/workspace/java/project/SSM/src/main/java"> <property name="enableSubPackages" value="true"/> </javaClientGenerator> <!--生成对应表及类名--> <table tableName="user" domainObjectName="User"/> </context> </generatorConfiguration>

命令行运行maven命令 

mvn mybatis-generator:generate

生成User表的Mapper.xml文件、bean和对应的接口，bean和接口下面会说到 

<?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="com.demo.dao.UserMapper"> <resultMap id="BaseResultMap" type="com.demo.bean.User"> <id column="id" jdbcType="INTEGER" property="id" /> <result column="name" jdbcType="CHAR" property="name" /> <result column="password" jdbcType="CHAR" property="password" /> </resultMap> <sql id="Example_Where_Clause"> <where> <foreach collection="oredCriteria" item="criteria" separator="or"> <if test="criteria.valid"> <trim prefix="(" prefixOverrides="and" suffix=")"> <foreach collection="criteria.criteria" item="criterion"> <choose> <when test="criterion.noValue"> and ${criterion.condition} </when> <when test="criterion.singleValue"> and ${criterion.condition} #{criterion.value} </when> <when test="criterion.betweenValue"> and ${criterion.condition} #{criterion.value} and #{criterion.secondValue} </when> <when test="criterion.listValue"> and ${criterion.condition} <foreach close=")" collection="criterion.value" item="listItem" open="(" separator=","> #{listItem} </foreach> </when> </choose> </foreach> </trim> </if> </foreach> </where> </sql> <sql id="Update_By_Example_Where_Clause"> <where> <foreach collection="example.oredCriteria" item="criteria" separator="or"> <if test="criteria.valid"> <trim prefix="(" prefixOverrides="and" suffix=")"> <foreach collection="criteria.criteria" item="criterion"> <choose> <when test="criterion.noValue"> and ${criterion.condition} </when> <when test="criterion.singleValue"> and ${criterion.condition} #{criterion.value} </when> <when test="criterion.betweenValue"> and ${criterion.condition} #{criterion.value} and #{criterion.secondValue} </when> <when test="criterion.listValue"> and ${criterion.condition} <foreach close=")" collection="criterion.value" item="listItem" open="(" separator=","> #{listItem} </foreach> </when> </choose> </foreach> </trim> </if> </foreach> </where> </sql> <sql id="Base_Column_List"> id, name, password </sql> <select id="selectByExample" parameterType="com.demo.bean.UserExample" resultMap="BaseResultMap"> select <if test="distinct"> distinct </if> <include refid="Base_Column_List" /> from user <if test="_parameter != null"> <include refid="Example_Where_Clause" /> </if> <if test="orderByClause != null"> order by ${orderByClause} </if> </select> <select id="selectByPrimaryKey" parameterType="java.lang.Integer" resultMap="BaseResultMap"> select <include refid="Base_Column_List" /> from user
    where id = #{id,jdbcType=INTEGER} </select> <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer"> delete from user
    where id = #{id,jdbcType=INTEGER} </delete> <delete id="deleteByExample" parameterType="com.demo.bean.UserExample"> delete from user <if test="_parameter != null"> <include refid="Example_Where_Clause" /> </if> </delete> <insert id="insert" parameterType="com.demo.bean.User"> insert into user (id, name, password)
    values (#{id,jdbcType=INTEGER}, #{name,jdbcType=CHAR}, #{password,jdbcType=CHAR}) </insert> <insert id="insertSelective" parameterType="com.demo.bean.User"> insert into user <trim prefix="(" suffix=")" suffixOverrides=","> <if test="id != null"> id, </if> <if test="name != null"> name, </if> <if test="password != null"> password, </if> </trim> <trim prefix="values (" suffix=")" suffixOverrides=","> <if test="id != null"> #{id,jdbcType=INTEGER}, </if> <if test="name != null"> #{name,jdbcType=CHAR}, </if> <if test="password != null"> #{password,jdbcType=CHAR}, </if> </trim> </insert> <select id="countByExample" parameterType="com.demo.bean.UserExample" resultType="java.lang.Long"> select count(*) from user <if test="_parameter != null"> <include refid="Example_Where_Clause" /> </if> </select> <update id="updateByExampleSelective" parameterType="map"> update user <set> <if test="record.id != null"> id = #{record.id,jdbcType=INTEGER}, </if> <if test="record.name != null"> name = #{record.name,jdbcType=CHAR}, </if> <if test="record.password != null"> password = #{record.password,jdbcType=CHAR}, </if> </set> <if test="_parameter != null"> <include refid="Update_By_Example_Where_Clause" /> </if> </update> <update id="updateByExample" parameterType="map"> update user
    set id = #{record.id,jdbcType=INTEGER},
      name = #{record.name,jdbcType=CHAR},
      password = #{record.password,jdbcType=CHAR} <if test="_parameter != null"> <include refid="Update_By_Example_Where_Clause" /> </if> </update> <update id="updateByPrimaryKeySelective" parameterType="com.demo.bean.User"> update user <set> <if test="name != null"> name = #{name,jdbcType=CHAR}, </if> <if test="password != null"> password = #{password,jdbcType=CHAR}, </if> </set> where id = #{id,jdbcType=INTEGER} </update> <update id="updateByPrimaryKey" parameterType="com.demo.bean.User"> update user
    set name = #{name,jdbcType=CHAR},
      password = #{password,jdbcType=CHAR}
    where id = #{id,jdbcType=INTEGER} </update> </mapper>
3.7 web配置文件web.xml 
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1"> <!-- 起始欢迎界面 --> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> <!-- 错误跳转页面 --> <error-page> <!-- 路径不正确 --> <error-code>404</error-code> <location>/error/404.jsp</location> </error-page> <error-page> <!-- 没有访问权限，访问被禁止 --> <error-code>405</error-code> <location>/error/405.jsp</location> </error-page> <error-page> <!-- 内部错误 --> <error-code>500</error-code> <location>/error/500.jsp</location> </error-page> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:application.xml</param-value> </context-param> <!-- Spring字符集过滤器 --> <filter> <filter-name>SpringEncodingFilter</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>SpringEncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <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-mvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>dispatcher</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>

4.接口和类

4.1 com.demo.bean下的User.java和UserExample.java

这两个类是由MBG生成的 

package com.demo.bean; public class User { private Integer id; private String name; private String password; public Integer getId() { return id;
    } public void setId(Integer id) { this.id = id;
    } public String getName() { return name;
    } public void setName(String name) { this.name = name == null ? null : name.trim();
    } public String getPassword() { return password;
    } public void setPassword(String password) { this.password = password == null ? null : password.trim();
    }
}

Example类用于构造复杂的筛选条件 

package com.demo.bean;

import java.util.ArrayList;
import java.util.List; public class UserExample { protected String orderByClause; protected boolean distinct; protected List<Criteria> oredCriteria; public UserExample() {
        oredCriteria = new ArrayList<Criteria>();
    } public void setOrderByClause(String orderByClause) { this.orderByClause = orderByClause;
    } public String getOrderByClause() { return orderByClause;
    } public void setDistinct(boolean distinct) { this.distinct = distinct;
    } public boolean isDistinct() { return distinct;
    } public List<Criteria> getOredCriteria() { return oredCriteria;
    } public void or(Criteria criteria) {
        oredCriteria.add(criteria);
    } public Criteria or() {
        Criteria criteria = createCriteriaInternal();
        oredCriteria.add(criteria); return criteria;
    } public Criteria createCriteria() {
        Criteria criteria = createCriteriaInternal(); if (oredCriteria.size() == 0) {
            oredCriteria.add(criteria);
        } return criteria;
    } protected Criteria createCriteriaInternal() {
        Criteria criteria = new Criteria(); return criteria;
    } public void clear() {
        oredCriteria.clear();
        orderByClause = null;
        distinct = false;
    } protected abstract static class GeneratedCriteria { protected List<Criterion> criteria; protected GeneratedCriteria() {
            super();
            criteria = new ArrayList<Criterion>();
        } public boolean isValid() { return criteria.size() > 0;
        } public List<Criterion> getAllCriteria() { return criteria;
        } public List<Criterion> getCriteria() { return criteria;
        } protected void addCriterion(String condition) { if (condition == null) { throw new RuntimeException("Value for condition cannot be null");
            }
            criteria.add(new Criterion(condition));
        } protected void addCriterion(String condition, Object value, String property) { if (value == null) { throw new RuntimeException("Value for " + property + " cannot be null");
            }
            criteria.add(new Criterion(condition, value));
        } protected void addCriterion(String condition, Object value1, Object value2, String property) { if (value1 == null || value2 == null) { throw new RuntimeException("Between values for " + property + " cannot be null");
            }
            criteria.add(new Criterion(condition, value1, value2));
        } public Criteria andIdIsNull() {
            addCriterion("id is null"); return (Criteria) this;
        } public Criteria andIdIsNotNull() {
            addCriterion("id is not null"); return (Criteria) this;
        } public Criteria andIdEqualTo(Integer value) {
            addCriterion("id =", value, "id"); return (Criteria) this;
        } public Criteria andIdNotEqualTo(Integer value) {
            addCriterion("id <>", value, "id"); return (Criteria) this;
        } public Criteria andIdGreaterThan(Integer value) {
            addCriterion("id >", value, "id"); return (Criteria) this;
        } public Criteria andIdGreaterThanOrEqualTo(Integer value) {
            addCriterion("id >=", value, "id"); return (Criteria) this;
        } public Criteria andIdLessThan(Integer value) {
            addCriterion("id <", value, "id"); return (Criteria) this;
        } public Criteria andIdLessThanOrEqualTo(Integer value) {
            addCriterion("id <=", value, "id"); return (Criteria) this;
        } public Criteria andIdIn(List<Integer> values) {
            addCriterion("id in", values, "id"); return (Criteria) this;
        } public Criteria andIdNotIn(List<Integer> values) {
            addCriterion("id not in", values, "id"); return (Criteria) this;
        } public Criteria andIdBetween(Integer value1, Integer value2) {
            addCriterion("id between", value1, value2, "id"); return (Criteria) this;
        } public Criteria andIdNotBetween(Integer value1, Integer value2) {
            addCriterion("id not between", value1, value2, "id"); return (Criteria) this;
        } public Criteria andNameIsNull() {
            addCriterion("name is null"); return (Criteria) this;
        } public Criteria andNameIsNotNull() {
            addCriterion("name is not null"); return (Criteria) this;
        } public Criteria andNameEqualTo(String value) {
            addCriterion("name =", value, "name"); return (Criteria) this;
        } public Criteria andNameNotEqualTo(String value) {
            addCriterion("name <>", value, "name"); return (Criteria) this;
        } public Criteria andNameGreaterThan(String value) {
            addCriterion("name >", value, "name"); return (Criteria) this;
        } public Criteria andNameGreaterThanOrEqualTo(String value) {
            addCriterion("name >=", value, "name"); return (Criteria) this;
        } public Criteria andNameLessThan(String value) {
            addCriterion("name <", value, "name"); return (Criteria) this;
        } public Criteria andNameLessThanOrEqualTo(String value) {
            addCriterion("name <=", value, "name"); return (Criteria) this;
        } public Criteria andNameLike(String value) {
            addCriterion("name like", value, "name"); return (Criteria) this;
        } public Criteria andNameNotLike(String value) {
            addCriterion("name not like", value, "name"); return (Criteria) this;
        } public Criteria andNameIn(List<String> values) {
            addCriterion("name in", values, "name"); return (Criteria) this;
        } public Criteria andNameNotIn(List<String> values) {
            addCriterion("name not in", values, "name"); return (Criteria) this;
        } public Criteria andNameBetween(String value1, String value2) {
            addCriterion("name between", value1, value2, "name"); return (Criteria) this;
        } public Criteria andNameNotBetween(String value1, String value2) {
            addCriterion("name not between", value1, value2, "name"); return (Criteria) this;
        } public Criteria andPasswordIsNull() {
            addCriterion("password is null"); return (Criteria) this;
        } public Criteria andPasswordIsNotNull() {
            addCriterion("password is not null"); return (Criteria) this;
        } public Criteria andPasswordEqualTo(String value) {
            addCriterion("password =", value, "password"); return (Criteria) this;
        } public Criteria andPasswordNotEqualTo(String value) {
            addCriterion("password <>", value, "password"); return (Criteria) this;
        } public Criteria andPasswordGreaterThan(String value) {
            addCriterion("password >", value, "password"); return (Criteria) this;
        } public Criteria andPasswordGreaterThanOrEqualTo(String value) {
            addCriterion("password >=", value, "password"); return (Criteria) this;
        } public Criteria andPasswordLessThan(String value) {
            addCriterion("password <", value, "password"); return (Criteria) this;
        } public Criteria andPasswordLessThanOrEqualTo(String value) {
            addCriterion("password <=", value, "password"); return (Criteria) this;
        } public Criteria andPasswordLike(String value) {
            addCriterion("password like", value, "password"); return (Criteria) this;
        } public Criteria andPasswordNotLike(String value) {
            addCriterion("password not like", value, "password"); return (Criteria) this;
        } public Criteria andPasswordIn(List<String> values) {
            addCriterion("password in", values, "password"); return (Criteria) this;
        } public Criteria andPasswordNotIn(List<String> values) {
            addCriterion("password not in", values, "password"); return (Criteria) this;
        } public Criteria andPasswordBetween(String value1, String value2) {
            addCriterion("password between", value1, value2, "password"); return (Criteria) this;
        } public Criteria andPasswordNotBetween(String value1, String value2) {
            addCriterion("password not between", value1, value2, "password"); return (Criteria) this;
        }
    } public static class Criteria extends GeneratedCriteria { protected Criteria() {
            super();
        }
    } public static class Criterion { private String condition; private Object value; private Object secondValue; private boolean noValue; private boolean singleValue; private boolean betweenValue; private boolean listValue; private String typeHandler; public String getCondition() { return condition;
        } public Object getValue() { return value;
        } public Object getSecondValue() { return secondValue;
        } public boolean isNoValue() { return noValue;
        } public boolean isSingleValue() { return singleValue;
        } public boolean isBetweenValue() { return betweenValue;
        } public boolean isListValue() { return listValue;
        } public String getTypeHandler() { return typeHandler;
        } protected Criterion(String condition) {
            super(); this.condition = condition; this.typeHandler = null; this.noValue = true;
        } protected Criterion(String condition, Object value, String typeHandler) {
            super(); this.condition = condition; this.value = value; this.typeHandler = typeHandler; if (value instanceof List<?>) { this.listValue = true;
            } else { this.singleValue = true;
            }
        } protected Criterion(String condition, Object value) { this(condition, value, null);
        } protected Criterion(String condition, Object value, Object secondValue, String typeHandler) {
            super(); this.condition = condition; this.value = value; this.secondValue = secondValue; this.typeHandler = typeHandler; this.betweenValue = true;
        } protected Criterion(String condition, Object value, Object secondValue) { this(condition, value, secondValue, null);
        }
    }
}
4.2 com.demo.dao下的UserMapper.java

这个DAO也是MBG生成的，这下体会到MBG的好处了吧，一下子帮你生成了这么多代码，年轻人可以少熬点夜了~ 

package com.demo.dao; import com.demo.bean.User; import com.demo.bean.UserExample; import java.util.List; import org.apache.ibatis.annotations.Param; public interface UserMapper { long countByExample(UserExample example); int deleteByExample(UserExample example); int deleteByPrimaryKey(Integer id); int insert(User record); int insertSelective(User record);

    List<User> selectByExample(UserExample example);

    User selectByPrimaryKey(Integer id); int updateByExampleSelective(@Param("record") User record, @Param("example") UserExample example); int updateByExample(@Param("record") User record, @Param("example") UserExample example); int updateByPrimaryKeySelective(User record); int updateByPrimaryKey(User record);
}
4.3 com.demo.service下的UserService.java接口

这里只定义了简单的增删查改方法 

package com.demo.service; import com.demo.bean.User; import java.util.List; public interface UserService { void insertUser(User user); void deleteUser(int id);

    User findUserById(Integer id);

    List<User> findAllUsers(); void updateUser(User user);
}
4.4 com.demo.serviceImpl下的UserServiceImpl.java

UserServiceImpl实现了UserService，通过注入UserMapper 对数据进行操作 

package com.demo.serviceImpl; import com.demo.bean.User; import com.demo.bean.UserExample; import com.demo.dao.UserMapper; import com.demo.service.UserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import java.util.List; @Service public class UserServiceImpl implements UserService { @Autowired private UserMapper userMapper; @Override public void insertUser(User user) {
        userMapper.insert(user);
    } @Override public void deleteUser(int id) {
        UserExample userExample = new UserExample();
        userExample.createCriteria().andIdEqualTo(id);
        userMapper.deleteByExample(userExample);
    } @Override public User findUserById(Integer id) { return userMapper.selectByPrimaryKey(id);
    } @Override public List<User> findAllUsers() { return userMapper.selectByExample(null);
    } @Override public void updateUser(User user) {
        userMapper.updateByPrimaryKey(user);
    }

}
4.5 com.demo.controller下的UserController.java

MVC模式下的控制器，通过注入的UserService完成相关业务 

package com.demo.controller; import com.demo.bean.User; import com.demo.service.UserService; import org.apache.logging.log4j.LogManager; import org.apache.logging.log4j.Logger; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.ResponseBody; @Controller
@RequestMapping(value = "/user")
public class UserController {

    private static Logger logger = LogManager.getLogger(); @Autowired
    private UserService userService; @RequestMapping(value = "/{id}", method = RequestMethod.GET)
    @ResponseBody
    public User findUserById(@PathVariable("id") Integer id) {
        User user = userService.findUserById(id); logger.info(user.toString()); return user; }
}

5.测试

将项目部署到本地的Tomcat上，打开你的chrome，访问： 

http://localhost:8080/user/1

浏览器访问服务器，服务器成功返回一个json数据

郑重声明：本文版权归原作者所有，转载文章仅为传播更多信息之目的，如作者信息标记有误，请第一时间联系我们修改或删除，多谢。
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