乐趣区

关于ssm:SSM框架环境搭建

jiezi

SSM-CRUD

根底环境搭建

创立 maven 工程

next,finish，期待创立实现，创立实现后，src/main 下只有 webapp 文件夹，咱们须要手动创立 java 和 resources, 鼠标右击 main,new folder, 将 java 改成 Sources 类型，resources 变成 Resources 类型

引入我的项目依赖

  • spring
  • springmvc
  • mybatis
  • 数据库连接池，驱动
  • 其它（jstl,servlet-api,junit）

编写 ssm 整合的配置文件

web.xml

增加束缚 

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

配置 spring，springmvc，字符过滤器，Restful URI

<!--1、启动 spring 容器 -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <!--2、配置 springMvc 的前端控制器 -->
    <servlet>
        <servlet-name>dispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!-- 3、字符编码过滤器，肯定要放在所有过滤器之前 -->
    <filter>
        <filter-name>CharacterEncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>utf-8</param-value>
        </init-param>
        <init-param>
            <param-name>forceRequestEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
        <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>
    <!-- 4、应用 Rest 格调的 URI，将页面一般的 post 申请转为指定的 delete 或者 put 申请 -->
    <filter>
        <filter-name>HiddenHttpMethodFilter</filter-name>
        <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>HiddenHttpMethodFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <filter>
        <filter-name>HttpPutFormContentFilter</filter-name>
        <filter-class>org.springframework.web.filter.HttpPutFormContentFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>HttpPutFormContentFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

springmvc 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:mvc="http://www.springframework.org/schema/mvc"
       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.xsd">

    <!--SpringMVC 的配置文件，蕴含网站跳转逻辑的管制，配置 -->
    <context:component-scan base-package="com.yu" use-default-filters="false">
        <!-- 只扫描控制器 -->
        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>

    <!-- 配置视图解析器，不便页面返回  -->

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

    <!-- 两个标准配置  -->
    <!-- 将 springmvc 不能解决的申请交给 tomcat -->
    <mvc:default-servlet-handler/>
    <!-- 能反对 springmvc 更高级的一些性能，JSR303 校验，快捷的 ajax... 映射动静申请 -->
    <mvc:annotation-driven/>
</beans>

spring 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.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">

    <context:component-scan base-package="com.yu">
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" />
    </context:component-scan>

    <!--spring 配置文件，这里次要配置和业务逻辑无关的 -->
    <!--=================== 数据源，事务管制，xxx ================-->
    <context:property-placeholder location="classpath:dbconfig.properties" />
    <bean id="pooledDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="jdbcUrl" value="${jdbc.jdbcUrl}"/>
        <property name="driverClass" value="${jdbc.driverClass}"/>
        <property name="user" value="${jdbc.user}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <!-- 整合 mybatis-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 指定 mybatis 全局配置文件的地位 -->
        <property name="configLocation" value="classpath:mybatis-config.xml"></property>
        <property name="dataSource" ref="pooledDataSource"></property>
        <!-- 指定 mybatis，mapper 文件的地位 -->
        <property name="mapperLocations" value="classpath:mapper/*.xml"></property>
    </bean>

    <!-- 配置扫描器，将 mybatis 接口的实现退出到 ioc 容器中 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!-- 扫描所有 dao 接口的实现，退出到 ioc 容器中 -->
        <property name="basePackage" value="com.yu.crud.dao"></property>
    </bean>

    <!-- 配置一个能够执行批量的 sqlSession -->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <constructor-arg name="sqlSessionFactory" ref="sqlSessionFactory"></constructor-arg>
        <constructor-arg name="executorType" value="BATCH"></constructor-arg>
    </bean>
    <!--=============================================  -->

    <!-- =============== 事务管制的配置 ================-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <!-- 管制住数据源  -->
        <property name="dataSource" ref="pooledDataSource"></property>
    </bean>
    <!-- 开启基于注解的事务，应用 xml 配置模式的事务（必要次要的都是应用配置式）-->
    <aop:config>
        <!-- 切入点表达式 -->
        <aop:pointcut expression="execution(* com.yu.crud.service..*(..))" id="txPoint"/>
        <!-- 配置事务加强 -->
        <aop:advisor advice-ref="txAdvice" pointcut-ref="txPoint"/>
    </aop:config>

    <!-- 配置事务加强，事务如何切入  -->
    <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <tx:attributes>
            <!-- 所有办法都是事务办法 -->
            <tx:method name="*"/>
            <!-- 以 get 开始的所有办法  -->
            <tx:method name="get*" read-only="true"/>
        </tx:attributes>
    </tx:advice>

    <!-- Spring 配置文件的外围点（数据源、与 mybatis 的整合，事务管制）-->
</beans>

数据源配置文件 dbconfig.properties

jdbc.jdbcUrl=jdbc:mysql://localhost:3306/ssm_crud
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.user=root
jdbc.password=123456

mybatis 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>
    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>
    
    <typeAliases>
        <package name="com.atguigu.crud.bean"/>
    </typeAliases>
    
    <plugins>
        <plugin interceptor="com.github.pagehelper.PageInterceptor">
            <!-- 分页参数合理化  -->
            <property name="reasonable" value="true"/>
        </plugin>
    </plugins>

</configuration>

应用 mybatis 的逆向工程生成对应的 bean 以及 mapper

在以后我的项目下新建 mbg.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>

    <context id="DB2Tables" targetRuntime="MyBatis3">
        <commentGenerator>
            <property name="suppressAllComments" value="true" />
        </commentGenerator>
        <!-- 配置数据库连贯 -->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
            connectionURL="jdbc:mysql://localhost:3306/ssm_crud" userId="root"
            password="******">
        </jdbcConnection>

        <javaTypeResolver>
            <property name="forceBigDecimals" value="false" />
        </javaTypeResolver>

        <!-- 指定 javaBean 生成的地位 -->
        <javaModelGenerator targetPackage="com.yu.crud.bean"
            targetProject=".\src\main\java">
            <property name="enableSubPackages" value="true" />
            <property name="trimStrings" value="true" />
        </javaModelGenerator>

        <!-- 指定 sql 映射文件生成的地位 -->
        <sqlMapGenerator targetPackage="mapper" targetProject=".\src\main\resources">
            <property name="enableSubPackages" value="true" />
        </sqlMapGenerator>

        <!-- 指定 dao 接口生成的地位，mapper 接口 -->
        <javaClientGenerator type="XMLMAPPER"
            targetPackage="com.yu.crud.dao" targetProject=".\src\main\java">
            <property name="enableSubPackages" value="true" />
        </javaClientGenerator>

        <!-- table 指定每个表的生成策略 -->
        <table tableName="tbl_emp" domainObjectName="Employee"></table>
        <table tableName="tbl_dept" domainObjectName="Department"></table>
    </context>
</generatorConfiguration>

在 test 包下新建 MBGTest 来逆向生成 bean 和 mapper

public class MBGTest {public static void main(String[] args) throws Exception {List<String> warnings = new ArrayList<String>();
        boolean overwrite = true;
        File configFile = new File("mbg.xml");
        ConfigurationParser cp = new ConfigurationParser(warnings);
        Configuration config = cp.parseConfiguration(configFile);
        DefaultShellCallback callback = new DefaultShellCallback(overwrite);
        MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config,
                callback, warnings);
        myBatisGenerator.generate(null);
    }
}

因为员工表寄存的是部门 id，所以要想当前查问员工列表的时候显示部门名称又不想执行两次 sql，须要增加连表查询方法，在 dao 下的 EmployeeMapper 接口下增加两个办法，

 // 查问员工同时带部门信息
 List<Employee> selectByExampleWithDept(EmployeeExample example);

 Employee selectByPrimaryKeyWithDept(Integer empId);

在 EmployeeMapper.xml 外面也增加上面的代码 

<resultMap type="com.yu.crud.bean.Employee" id="WithDeptResultMap">
    <id column="emp_id" jdbcType="INTEGER" property="empId" />
    <result column="emp_name" jdbcType="VARCHAR" property="empName" />
    <result column="gender" jdbcType="CHAR" property="gender" />
    <result column="email" jdbcType="VARCHAR" property="email" />
    <result column="d_id" jdbcType="INTEGER" property="dId" />
    <!-- 指定联结查问出的部门字段的封装 -->
    <association property="department" javaType="com.yu.crud.bean.Department">
      <id column="dept_id" property="deptId"/>
      <result column="dept_name" property="deptName"/>
    </association>
 </resultMap>
 
  <sql id="WithDept_Column_List">
      e.emp_id, e.emp_name, e.gender, e.email, e.d_id,d.dept_id,d.dept_name
  </sql>

  <!-- 查问员工同时带部门信息 -->
  <select id="selectByExampleWithDept" resultMap="BaseResultMap">
    select
    <if test="distinct">
      distinct
    </if>
    <include refid="WithDept_Column_List" />
    FROM tbl_emp e
    left join tbl_dept d on e.`d_id`=d.`dept_id`
    <if test="_parameter != null">
      <include refid="Example_Where_Clause" />
    </if>
    <if test="orderByClause != null">
      order by ${orderByClause}
    </if>
  </select>

  <select id="selectByPrimaryKeyWithDept" resultMap="WithDeptResultMap">
    select
    <include refid="WithDept_Column_List" />
    FROM tbl_emp e
    left join tbl_dept d on e.`d_id`=d.`dept_id`
    where emp_id = #{empId,jdbcType=INTEGER}
  </select>

最初写一个测试方法，测试一下 CRUD

/**
 *  测试 dao 层的工作
 *  @author yy
 *  1、导入 SpringTest 模块
 *  2、@ContextConfiguration 指定 Spring 配置文件的地位
 *  3、间接 autowired 要应用的组件即可
 */

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"classpath:applicationContext.xml"})
public class MapperTest {
    
    @Autowired
    DepartmentMapper departmentMapper;
    
    @Autowired
    EmployeeMapper employeeMapper;
    
    @Autowired
    SqlSession sqlSession;
    
    /**
     * 测试 DepartmentMapper
     */
    @Test
    public void testCRUD(){
        //1、插入几个部门
//        departmentMapper.insertSelective(new Department(null, "开发部"));
//        departmentMapper.insertSelective(new Department(null, "测试部"));
        
        //2、生成员工数据，测试员工插入
        //employeeMapper.insertSelective(new Employee(null, "Jerry", "M", "Jerry@atguigu.com", 2));
        
        //3、批量插入多个员工；批量，应用能够执行批量操作的 sqlSession。EmployeeMapper mapper = sqlSession.getMapper(EmployeeMapper.class);
        for(int i = 0;i<1000;i++){String uid = UUID.randomUUID().toString().substring(0,5)+i;
            mapper.insertSelective(new Employee(null,uid, "M", uid+"@163.com", 3));
        }
        System.out.println("批量实现");
        
    }

}
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