一、小工具:

fastJson：温少的json小工具，打印非常好用

JsonView: json查看工具

d

二、项目配置

    1.pom.xml

    注意：spring包尽量置前，防止包依赖旧版本

<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/maven-v4_0_0.xsd">   <modelVersion>4.0.0</modelVersion>   <groupId>sy.testmybatis</groupId>   <artifactId>testmybatis</artifactId>   <packaging>war</packaging>   <version>0.0.1-SNAPSHOT</version>   <name>testmybatis Maven Webapp</name>   <url>http://maven.apache.org</url>   <dependencies>    <dependency>     <groupId>org.springframework</groupId>     <artifactId>spring-test</artifactId>     <version>3.2.0.RELEASE</version>    </dependency>    <dependency>     <groupId>org.springframework</groupId>     <artifactId>spring-webmvc</artifactId>     <version>3.2.0.RELEASE</version>    </dependency>    <dependency>     <groupId>org.springframework</groupId>     <artifactId>spring-core</artifactId>     <version>3.2.0.RELEASE</version>    </dependency>    <dependency>              <groupId>org.apache.maven.plugins</groupId>              <artifactId>maven-surefire-plugin</artifactId>              <version>2.17</version>              <!-- <configuration>                  <testFailureIgnore>true</testFailureIgnore>              </configuration> -->          </dependency>    <dependency>     <groupId>org.mybatis</groupId>     <artifactId>mybatis</artifactId>     <version>3.1.1</version>    </dependency>    <dependency>     <groupId>org.mybatis</groupId>     <artifactId>mybatis-spring</artifactId>     <version>1.1.1</version>    </dependency>    <dependency>     <groupId>mysql</groupId>     <artifactId>mysql-connector-java</artifactId>     <version>5.1.21</version>    </dependency>    <dependency>     <groupId>junit</groupId>     <artifactId>junit</artifactId>     <version>4.11</version>     <scope>test</scope>    </dependency>    <dependency>     <groupId>com.alibaba</groupId>     <artifactId>druid</artifactId>     <version>0.2.9</version>    </dependency>    <dependency>     <groupId>org.aspectj</groupId>     <artifactId>aspectjweaver</artifactId>     <version>1.7.1</version>    </dependency>    <dependency>     <groupId>org.codehaus.jackson</groupId>     <artifactId>jackson-mapper-asl</artifactId>     <version>1.9.11</version>    </dependency>    <dependency>     <groupId>commons-fileupload</groupId>     <artifactId>commons-fileupload</artifactId>     <version>1.2.2</version>    </dependency>    <dependency>     <groupId>javax.servlet</groupId>     <artifactId>servlet-api</artifactId>     <version>3.0-alpha-1</version>    </dependency>    <dependency>     <groupId>log4j</groupId>     <artifactId>log4j</artifactId>     <version>1.2.17</version>    </dependency>    <dependency>     <groupId>com.alibaba</groupId>     <artifactId>fastjson</artifactId>     <version>1.1.26</version>    </dependency>   </dependencies>   <build>   </build>  </project>

2.web.xml

<?xml version="1.0" encoding="UTF-8"?>  <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 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">   <display-name>mybatis</display-name>   <context-param>    <param-name>contextConfigLocation</param-name>    <param-value>classpath:spring.xml,classpath:spring-mybatis.xml</param-value>   </context-param>   <filter>    <description>字符集过滤器</description>    <filter-name>encodingFilter</filter-name>    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>    <init-param>     <description>字符集编码</description>     <param-name>encoding</param-name>     <param-value>UTF-8</param-value>    </init-param>   </filter>   <filter-mapping>    <filter-name>encodingFilter</filter-name>    <url-pattern>/*</url-pattern>   </filter-mapping>   <listener>    <description>spring监听器</description>    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>   </listener>      <!-- 防止spring内存溢出监听器 -->   <listener>    <listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class>   </listener>      <!-- spring mvc servlet -->   <servlet>    <description>spring mvc servlet</description>    <servlet-name>springMvc</servlet-name>    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>    <init-param>     <description>spring mvc 配置文件</description>     <param-name>contextConfigLocation</param-name>     <param-value>classpath:spring-mvc.xml</param-value>    </init-param>    <load-on-startup>1</load-on-startup>   </servlet>      <servlet-mapping>    <servlet-name>springMvc</servlet-name>    <url-pattern>*.do</url-pattern>   </servlet-mapping>      <welcome-file-list>    <welcome-file>/index.jsp</welcome-file>   </welcome-file-list>      <!-- 配置session超时时间，单位分钟 -->   <session-config>    <session-timeout>15</session-timeout>   </session-config>  </web-app>

3.spring.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:context="http://www.springframework.org/schema/context" xsi:schemaLocation="  http://www.springframework.org/schema/beans  http://www.springframework.org/schema/beans/spring-beans-3.2.xsd  http://www.springframework.org/schema/context  http://www.springframework.org/schema/context/spring-context-3.2.xsd">     <!-- 引入属性文件 -->   <context:property-placeholder location="classpath:config.properties" />     <!-- 自动扫描(自动注入) -->   <context:component-scan base-package="sy.service" />     </beans>

4.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:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="  http://www.springframework.org/schema/beans   http://www.springframework.org/schema/beans/spring-beans-3.2.xsd   http://www.springframework.org/schema/tx   http://www.springframework.org/schema/tx/spring-tx-3.2.xsd  http://www.springframework.org/schema/aop   http://www.springframework.org/schema/aop/spring-aop-3.2.xsd  ">     <!-- JNDI方式配置数据源 -->   <!-- <bean id="dataSource" class="org.springframework.jndi.JndiObjectFactoryBean"> <property name="jndiName" value="${jndiName}"></property> </bean> -->     <!-- 配置数据源 -->   <bean name="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">    <property name="url" value="${jdbc_url}" />    <property name="username" value="${jdbc_username}" />    <property name="password" value="${jdbc_password}" />      <!-- 初始化连接大小 -->    <property name="initialSize" value="0" />    <!-- 连接池最大使用连接数量 -->    <property name="maxActive" value="20" />    <!-- 连接池最大空闲 -->    <property name="maxIdle" value="20" />    <!-- 连接池最小空闲 -->    <property name="minIdle" value="0" />    <!-- 获取连接最大等待时间 -->    <property name="maxWait" value="60000" />      <!-- <property name="poolPreparedStatements" value="true" /> <property name="maxPoolPreparedStatementPerConnectionSize" value="33" /> -->    <property name="validationQuery" value="${validationQuery}" />    <property name="testOnBorrow" value="false" />    <property name="testOnReturn" value="false" />    <property name="testWhileIdle" value="true" />      <!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 -->    <property name="timeBetweenEvictionRunsMillis" value="60000" />    <!-- 配置一个连接在池中最小生存的时间，单位是毫秒 -->    <property name="minEvictableIdleTimeMillis" value="25200000" />      <!-- 打开removeAbandoned功能 -->    <property name="removeAbandoned" value="true" />    <!-- 1800秒，也就是30分钟 -->    <property name="removeAbandonedTimeout" value="1800" />    <!-- 关闭abanded连接时输出错误日志 -->    <property name="logAbandoned" value="true" />      <!-- 监控数据库 -->    <!-- <property name="filters" value="stat" /> -->    <property name="filters" value="mergeStat" />   </bean>     <!-- myBatis文件 -->   <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">    <property name="dataSource" ref="dataSource" />    <!-- 自动扫描entity目录, 省掉Configuration.xml里的手工配置 -->    <property name="mapperLocations" value="classpath:sy/mapping/*.xml" />   </bean>     <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">    <property name="basePackage" value="sy.dao" />    <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />   </bean>     <!-- 配置事务管理器 -->   <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">    <property name="dataSource" ref="dataSource" />   </bean>     <!-- 注解方式配置事物 -->   <!-- <tx:annotation-driven transaction-manager="transactionManager" /> -->     <!-- 拦截器方式配置事物 -->   <tx:advice id="transactionAdvice" transaction-manager="transactionManager">    <tx:attributes>     <tx:method name="add*" propagation="REQUIRED" />     <tx:method name="append*" propagation="REQUIRED" />     <tx:method name="insert*" propagation="REQUIRED" />     <tx:method name="save*" propagation="REQUIRED" />     <tx:method name="update*" propagation="REQUIRED" />     <tx:method name="modify*" propagation="REQUIRED" />     <tx:method name="edit*" propagation="REQUIRED" />     <tx:method name="delete*" propagation="REQUIRED" />     <tx:method name="remove*" propagation="REQUIRED" />     <tx:method name="repair" propagation="REQUIRED" />     <tx:method name="delAndRepair" propagation="REQUIRED" />       <tx:method name="get*" propagation="SUPPORTS" />     <tx:method name="find*" propagation="SUPPORTS" />     <tx:method name="load*" propagation="SUPPORTS" />     <tx:method name="search*" propagation="SUPPORTS" />     <tx:method name="datagrid*" propagation="SUPPORTS" />     <tx:method name="*" propagation="SUPPORTS" />    </tx:attributes>   </tx:advice>   <aop:config>    <aop:pointcut id="transactionPointcut" expression="execution(* sy.service..*Impl.*(..))" />    <aop:advisor pointcut-ref="transactionPointcut" advice-ref="transactionAdvice" />   </aop:config>     <!-- 配置druid监控spring jdbc -->   <bean id="druid-stat-interceptor" class="com.alibaba.druid.support.spring.stat.DruidStatInterceptor">   </bean>   <bean id="druid-stat-pointcut" class="org.springframework.aop.support.JdkRegexpMethodPointcut" scope="prototype">    <property name="patterns">     <list>      <value>sy.service.*</value>     </list>    </property>   </bean>      <aop:config>    <aop:advisor advice-ref="druid-stat-interceptor" pointcut-ref="druid-stat-pointcut" />   </aop:config>  </beans>

5. spring-mvc.xml

<?xml version="1.0" encoding="UTF-8"?>  <beans xmlns="http://www.springframework.org/schema/beans"       xmlns:mvc="http://www.springframework.org/schema/mvc"       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"       xmlns:p="http://www.springframework.org/schema/p"       xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans   http://www.springframework.org/schema/beans/spring-beans-3.2.xsd   http://www.springframework.org/schema/context   http://www.springframework.org/schema/context/spring-context-3.2.xsd   http://www.springframework.org/schema/mvc   http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">     <!-- 自动扫描controller包下的所有类，使其认为spring mvc的控制器 -->   <context:component-scan base-package="sy.controller" />     <!-- 避免IE执行AJAX时,返回JSON出现下载文件 -->   <bean id="mappingJacksonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">    <property name="supportedMediaTypes">     <list>      <value>text/html;charset=UTF-8</value>     </list>    </property>   </bean>     <!-- 启动Spring MVC的注解功能，完成请求和注解POJO的映射 -->   <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">    <property name="messageConverters">     <list>      <ref bean="mappingJacksonHttpMessageConverter" /><!-- json转换器 -->     </list>    </property>   </bean>     <!-- 对模型视图名称的解析，即在模型视图名称添加前后缀 -->   <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" p:prefix="/" p:suffix=".jsp" />     <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">    <property name="defaultEncoding">     <value>UTF-8</value>    </property>    <property name="maxUploadSize">     <value>32505856</value> <!-- 上传文件大小限制为31M，31*1024*1024 -->    </property>    <property name="maxInMemorySize">     <value>4096</value>    </property>   </bean>  </beans>

三、mybatis使用：crud操作及如何获取关联对象（用户和角色通过中间表多对多关联）

    1.mybatis generator使用

      1.1 generator配置：

<generatorConfiguration>   <!-- 数据库驱动包位置 -->   <!-- <classPathEntry location="D:\software\lib\mysql-connector-java-5.1.21.jar" /> -->   <classPathEntry location="C:\oracle\product\10.2.0\db_1\jdbc\lib\ojdbc14.jar" />   <context id="DB2Tables" targetRuntime="MyBatis3">    <commentGenerator>     <property name="suppressAllComments" value="true" />    </commentGenerator>    <!-- 数据库链接URL、用户名、密码 -->    <!-- <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/sy" userId="sypro" password="sypro"> -->    <jdbcConnection driverClass="oracle.jdbc.driver.OracleDriver" connectionURL="jdbc:oracle:thin:@localhost:1521:orcl" userId="msa" password="msa">    </jdbcConnection>    <javaTypeResolver>     <property name="forceBigDecimals" value="false" />    </javaTypeResolver>    <!-- 生成模型的包名和位置 -->    <javaModelGenerator targetPackage="sy.model" targetProject="D:\study\mybatis\src">     <property name="enableSubPackages" value="true" />     <property name="trimStrings" value="true" />    </javaModelGenerator>    <!-- 生成的映射文件包名和位置 -->    <sqlMapGenerator targetPackage="sy.mapping" targetProject="D:\study\mybatis\src">     <property name="enableSubPackages" value="true" />    </sqlMapGenerator>    <!-- 生成DAO的包名和位置 -->    <javaClientGenerator type="XMLMAPPER" targetPackage="sy.dao" targetProject="D:\study\mybatis\src">     <property name="enableSubPackages" value="true" />    </javaClientGenerator>    <!-- 要生成那些表(更改tableName和domainObjectName就可以) -->        <table tableName="trole" domainObjectName="Role" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false" />    <table tableName="tuser" domainObjectName="User" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false" />    <table tableName="tuser_trole" domainObjectName="UserRole" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false" />   </context>  </generatorConfiguration>

    1.2 generater 生成

        java -jar mybatis-generator-core-1.3.2.jar -configfile generator.xml -overwrite

    2.映射文件UserMapper.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="sy.dao.UserMapper">   <resultMap id="BaseResultMap" type="sy.model.User">    <id column="ID" property="id" jdbcType="VARCHAR" />    <result column="CREATEDATETIME" property="createdatetime" jdbcType="TIMESTAMP" />    <result column="MODIFYDATETIME" property="modifydatetime" jdbcType="TIMESTAMP" />    <result column="NAME" property="name" jdbcType="VARCHAR" />    <result column="PWD" property="pwd" jdbcType="VARCHAR" />    <result column="CREATE_TIME" property="createTime" jdbcType="DATE" />    <result column="UPDATE_TIME" property="updateTime" jdbcType="DATE" />   </resultMap>   <sql id="Base_Column_List">    ID, CREATEDATETIME, MODIFYDATETIME, NAME, PWD, CREATE_TIME, UPDATE_TIME   </sql>   <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.String">    select    <include refid="Base_Column_List" />    from tuser    where ID = #{id,jdbcType=VARCHAR}   </select>   <delete id="deleteByPrimaryKey" parameterType="java.lang.String">    delete from tuser    where ID = #{id,jdbcType=VARCHAR}   </delete>   <insert id="insert" parameterType="sy.model.User">    insert into tuser (ID, CREATEDATETIME, MODIFYDATETIME,    NAME, PWD, CREATE_TIME,    UPDATE_TIME)    values (#{id,jdbcType=VARCHAR}, #{createdatetime,jdbcType=TIMESTAMP}, #{modifydatetime,jdbcType=TIMESTAMP},    #{name,jdbcType=VARCHAR}, #{pwd,jdbcType=VARCHAR}, #{createTime,jdbcType=DATE},    #{updateTime,jdbcType=DATE})   </insert>   <insert id="insertSelective" parameterType="sy.model.User">    insert into tuser    <trim prefix="(" suffix=")" suffixOverrides=",">     <if test="id != null">      ID,     </if>     <if test="createdatetime != null">      CREATEDATETIME,     </if>     <if test="modifydatetime != null">      MODIFYDATETIME,     </if>     <if test="name != null">      NAME,     </if>     <if test="pwd != null">      PWD,     </if>     <if test="createTime != null">      CREATE_TIME,     </if>     <if test="updateTime != null">      UPDATE_TIME,     </if>    </trim>    <trim prefix="values (" suffix=")" suffixOverrides=",">     <if test="id != null">      #{id,jdbcType=VARCHAR},     </if>     <if test="createdatetime != null">      #{createdatetime,jdbcType=TIMESTAMP},     </if>     <if test="modifydatetime != null">      #{modifydatetime,jdbcType=TIMESTAMP},     </if>     <if test="name != null">      #{name,jdbcType=VARCHAR},     </if>     <if test="pwd != null">      #{pwd,jdbcType=VARCHAR},     </if>     <if test="createTime != null">      #{createTime,jdbcType=DATE},     </if>     <if test="updateTime != null">      #{updateTime,jdbcType=DATE},     </if>    </trim>   </insert>   <update id="updateByPrimaryKeySelective" parameterType="sy.model.User">    update tuser    <set>     <if test="createdatetime != null">      CREATEDATETIME = #{createdatetime,jdbcType=TIMESTAMP},     </if>     <if test="modifydatetime != null">      MODIFYDATETIME = #{modifydatetime,jdbcType=TIMESTAMP},     </if>     <if test="name != null">      NAME = #{name,jdbcType=VARCHAR},     </if>     <if test="pwd != null">      PWD = #{pwd,jdbcType=VARCHAR},     </if>     <if test="createTime != null">      CREATE_TIME = #{createTime,jdbcType=DATE},     </if>     <if test="updateTime != null">      UPDATE_TIME = #{updateTime,jdbcType=DATE},     </if>    </set>    where ID = #{id,jdbcType=VARCHAR}   </update>   <update id="updateByPrimaryKey" parameterType="sy.model.User">    update tuser    set CREATEDATETIME = #{createdatetime,jdbcType=TIMESTAMP},    MODIFYDATETIME = #{modifydatetime,jdbcType=TIMESTAMP},    NAME = #{name,jdbcType=VARCHAR},    PWD = #{pwd,jdbcType=VARCHAR},    CREATE_TIME = #{createTime,jdbcType=DATE},    UPDATE_TIME = #{updateTime,jdbcType=DATE}    where ID = #{id,jdbcType=VARCHAR}   </update>      <!-- N+1查询问题 -->   <select id="selectUserRole" parameterType="java.lang.String" resultType="sy.model.UserRole">    SELECT    tuser_trole.ID,    tuser_trole.ROLE_ID,    tuser_trole.USER_ID    FROM    tuser_trole    where tuser_trole.user_id=#{id,jdbcType=VARCHAR}   </select>      <resultMap type="sy.model.User" id="userResultMap" extends="BaseResultMap">    <collection property="userRoles" column="ID" javaType="list" select="selectUserRole" />   </resultMap>      <select id="getAll" resultMap="userResultMap">    select ID, CREATEDATETIME, MODIFYDATETIME, NAME, PWD from tuser   </select>     <resultMap type="sy.model.User" id="userResultMap2" extends="BaseResultMap">    <collection property="userRoles" javaType="list" ofType="sy.model.UserRole">     <id property="id" column="userrole_id" />     <result column="role_id" property="roleId" />     <result property="userId" column="user_id" />    </collection>   </resultMap>   <select id="getAll2" resultMap="userResultMap2">    SELECT    tuser.ID,    tuser.CREATEDATETIME,    tuser.MODIFYDATETIME,    tuser.`NAME`,    tuser.PWD,    tuser.CREATE_TIME,    tuser.UPDATE_TIME,    tuser_trole.ID userrole_id,    tuser_trole.ROLE_ID role_id,    tuser_trole.USER_ID user_id    FROM    tuser    JOIN tuser_trole ON tuser.ID = tuser_trole.USER_ID   </select>     <!-- 通过中间表对象UserRole获取角色 -->   <resultMap type="sy.model.User" id="userResultMap3" extends="BaseResultMap">    <collection property="userRoles" javaType="list" ofType="sy.model.UserRole">     <id property="id" column="userrole_id" />     <result column="role_id" property="roleId" />     <result property="userId" column="user_id" />       <association property="role" javaType="sy.model.Role">      <id property="id" column="role_id" />      <result property="text" column="role_text" />     </association>    </collection>   </resultMap>      <select id="getAll3" resultMap="userResultMap3">    SELECT    tuser.ID,    tuser.CREATEDATETIME,    tuser.MODIFYDATETIME,    tuser.`NAME`,    tuser.PWD,    tuser.CREATE_TIME,    tuser.UPDATE_TIME,    tuser_trole.ID userrole_id,    tuser_trole.ROLE_ID role_id,    tuser_trole.USER_ID user_id,    trole.ID role_id,    trole.TEXT role_text    FROM    tuser    JOIN tuser_trole ON tuser.ID = tuser_trole.USER_ID    JOIN trole ON tuser_trole.ROLE_ID = trole.ID   </select>      <!-- 直接获取角色，中间表对象UserRole -->   <resultMap type="sy.model.User" id="userResultMap4" extends="BaseResultMap">    <collection property="roles" javaType="list" ofType="sy.model.Role">     <id property="id" column="role_id" />     <result property="text" column="role_text" />    </collection>   </resultMap>      <select id="getAll4" resultMap="userResultMap4">    SELECT    tuser.ID,    tuser.CREATEDATETIME,    tuser.MODIFYDATETIME,    tuser.`NAME`,    tuser.PWD,    tuser.CREATE_TIME,    tuser.UPDATE_TIME,    tuser_trole.ID userrole_id,    tuser_trole.ROLE_ID,    tuser_trole.USER_ID,    trole.ID role_id,    trole.TEXT role_text    FROM    tuser    JOIN tuser_trole ON tuser.ID = tuser_trole.USER_ID    JOIN trole ON tuser_trole.ROLE_ID = trole.ID   </select>     </mapper>