详解环境搭建SSM

1.概述：

SSM即为spring 4 +spring mvc +mybatis 3.4.6

推荐使用maven或者gradle 来配置 下面给出maven配置方式

2.项目结构：

新建web项目

这里要特别说一下：如果你安装eclipse spring插件可以利用插件来检查多次依赖包，没有安装插件的推荐安装

spring elements>>beans>>显示了你用的标签，过去你需要记忆方式，或者说循规蹈矩的排除bean，现在直接使用这个插件，可以看到你注解标签下拥有的bean数，可以很好解决问题

3.pom文件

 <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.gitee.dgwcode</groupId>
     <artifactId>mybatis06_SSM</artifactId>
     <version>0.0.1-SNAPSHOT</version>

     <dependencies>
         <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-api</artifactId>
             <version>1.7.25</version>
         </dependency>
         <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-log4j12</artifactId>
             <version>1.7.25</version>
             <scope>test</scope>
         </dependency>

         <dependency>
             <groupId>javax.servlet</groupId>
             <artifactId>jstl</artifactId>
             <version>1.2</version>
         </dependency>

         <!-- 连接池 -->
         <dependency>
             <groupId>com.mchange</groupId>
             <artifactId>c3p0</artifactId>
             <version>0.9.5.2</version>
         </dependency>
         <dependency>
             <groupId>mysql</groupId>
             <artifactId>mysql-connector-java</artifactId>
             <version>5.1.39</version>
         </dependency>
         <!-- mybatis相关包 -->
         <dependency>
             <groupId>org.mybatis</groupId>
             <artifactId>mybatis</artifactId>
             <version>3.4.6</version>
         </dependency>
         <dependency>
             <groupId>org.mybatis</groupId>
             <artifactId>mybatis-spring</artifactId>
             <version>1.3.2</version>
         </dependency>
         <!-- spring 相关的一律包 -->
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-jdbc</artifactId>
             <version>4.3.9.RELEASE</version>
         </dependency>

         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-context</artifactId>
             <version>4.3.9.RELEASE</version>
         </dependency>
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-web</artifactId>
             <version>4.3.9.RELEASE</version>
         </dependency>
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-webmvc</artifactId>
             <version>4.3.9.RELEASE</version>
         </dependency>
         <dependency>
             <groupId>javax.servlet</groupId>
             <artifactId>javax.servlet-api</artifactId>
             <version>4.0.0-b07</version>
             <scope>provided</scope>
         </dependency>
         <dependency>
             <groupId>javax.servlet.jsp</groupId>
             <artifactId>jsp-api</artifactId>
             <version>2.2</version>
             <scope>provided</scope>
         </dependency>
     </dependencies>
 </project>

4.application

 <?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"
     xmlns:mybatis-spring="http://mybatis.org/schema/mybatis-spring"
     xsi:schemaLocation="http://mybatis.org/schema/mybatis-spring http://mybatis.org/schema/mybatis-spring-1.2.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
         http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">

         <!-- Spring希望管理所有的业务逻辑组件，等。。。 -->
     <context:component-scan base-package="com.gitee.dgwcode">
         <context:exclude-filter type="annotation"
             expression="org.springframework.stereotype.Controller" />
             <context:exclude-filter type="annotation"
             expression="org.springframework.web.bind.annotation.ControllerAdvice" />
     </context:component-scan>

     <!-- 引入数据库的配置文件 -->
     <context:property-placeholder location="classpath:dbconfig.properties" />
     <context:property-placeholder location="classpath:dbconfig.properties" />
     <!-- Spring用来控制业务逻辑。数据源、事务控制、aop -->
     <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
         <property name="jdbcUrl" value="${jdbc.url}"></property>
         <property name="driverClass" value="${jdbc.driver}"></property>
         <property name="user" value="${jdbc.username}"></property>
         <property name="password" value="${jdbc.password}"></property>
         <property name="initialPoolSize" value="10"></property>
         <property name="maxIdleTime" value="30"></property>
         <property name="maxPoolSize" value="100"></property>
         <property name="minPoolSize" value="10"></property>
     </bean>

     <!-- spring事务管理 -->
     <bean id="dataSourceTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
         <property name="dataSource" ref="dataSource"></property>
     </bean>

     <!-- 开启基于注解的事务 -->
     <tx:annotation-driven transaction-manager="dataSourceTransactionManager"/>

     <!--创建出SqlSessionFactory对象  -->
     <bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
         <property name="dataSource" ref="dataSource"></property>
         <!-- configLocation指定全局配置文件的位置 -->
         <property name="configLocation" value="classpath:mybatis-cfg.xml"></property>
         <!--mapperLocations: 指定mapper文件的位置-->
         <property name="mapperLocations" value="classpath*:mybatis/mapper/*.xml"></property>
     </bean>
     <!--配置一个可以进行批量执行的sqlSession 也可以配置sqlSessionTempplete -->
     <!-- <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
         <constructor-arg name="sqlSessionFactory" ref="sqlSessionFactoryBean"></constructor-arg>
         <constructor-arg name="executorType" value="BATCH"></constructor-arg>
     </bean> -->

     <!-- 扫描所有的mapper接口的实现，让这些mapper能够自动注入；
     base-package：指定mapper接口的包名
      -->
      <mybatis-spring:scan base-package="com.gitee.dgwcode.mapper"/>
     <!-- <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
         <property name="basePackage" value="com.atguigu.mybatis.dao"></property>
     </bean> -->

 </beans>

5:spring mvc .xml

这里你也可以选择在spring mvc 文件中配置事物，数据源，计划等

 <?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: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
         http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">

     <context:component-scan
         base-package="com.gitee.dgwcode" use-default-filters="false">
         <context:include-filter type="annotation"
             expression="org.springframework.stereotype.Controller" />
         <context:include-filter type="annotation"
             expression="org.springframework.web.bind.annotation.ControllerAdvice" />
     </context:component-scan>

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

     <mvc:annotation-driven></mvc:annotation-driven>
     <mvc:default-servlet-handler />

 </beans>

6：mybaits

SqlSessionFactoryBean 在sprinig代替了 SqlSessionFactoryBeanBuilde 所以原来的配置文件完全可以在spring的配置文件中进行，但是官方解释 配置属性是不完全的，那么你这里就要考虑是不是你要最基本的mybatis功能，还是说你要高度定制你自己的mybatis的各种

属性，所以你最好是保留这个配置文件

注意：我这个配置删除了一些无关配置，当前spring-mybat插件runing的时候也会忽略那么不需要的标签

 <?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>

     <!-- 配置指定使用LOG4J输出日志 -->
     <settings>
         <setting name="logImpl" value="LOG4J" />
         <!-- 配置驼峰语法 -->
         <setting name="mapUnderscoreToCamelCase" value="true" />
         <!-- 开启自动映射 -->
         <!-- <setting name="autoMappingBehavior" value="NONE"/> -->
         <!-- 懒加载 -->
         <setting name="lazyLoadingEnabled" value="false" />
         <setting name="cacheEnabled" value="true"/>
     </settings>

     <!-- 配置包的别名，这样我们在mapper中定义时，就不需要使用类的全限定名称，只需要使用类名即可 :值 主要解决 在结果映射中 需要全路径的问题.
         这个的包名: 是指 模型包名,也就是 对应结果实体类返回的名字. -->
     <typeAliases>
     </typeAliases>

     <!-- 类型处理器，mybatis3.4以后jdk1.8实现ljsr310 就不要加入原来默认的配置了 -->
     <typeHandlers>
         <!-- <typeHandler handler=""/> -->
     </typeHandlers>

     <!-- 使用外部数据库配置的方式 读取规则是就近原则：先properties 里的 在外部文件 -->
     <!-- <properties resource="dbconfig.properties"> <property name="username"
         value="root"/> <property name="password" value="root"/> </properties> -->

     <!-- 配置不同的数据库便于支持不同的数据， 在mapper通过 -->
     <databaseIdProvider type="DB_VENDOR">
         <property name="MySQL" value="mysql" />
         <!-- <property name="SQL Server" value="sqlserver" /> <property name="DB2"
             value="db2" /> <property name="Oracle" value="oracle" /> -->
     </databaseIdProvider>

 </configuration>

7：code文件

这里不贴出代码文件，其实就是实现一个最基本的crud，类如下图。

8：要说明的问题：

8.1:可能你已经习惯了Hihernate那套session使用方式，所以这里给出配置方式

在mybatis中对应的sqlSession，下面这段代码应该非常属性：

 private SqlSessionFactory sqlsession;

     @Before
     public void setUp() throws IOException {
         String path="mybatis.cfg.xml";
         InputStream stream = Resources.getResourceAsStream(path);
         sqlsession= new SqlSessionFactoryBuilder().build(stream);
     }

而对应的spring整合中，你只需要保证创建sqlSessionfactoryBean对象

 <!--创建出SqlSessionFactory对象  -->
     <bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
         <property name="dataSource" ref="dataSource"></property>
         <!-- configLocation指定全局配置文件的位置 -->
         <property name="configLocation" value="classpath:mybatis-cfg.xml"></property>
         <!--mapperLocations: 指定mapper文件的位置-->
         <property name="mapperLocations" value="classpath*:mybatis/mapper/*.xml"></property>
     </bean>

再想到hibernate 对应的factory，就有下面的注入方式

 public class UserDaoImpl implements UserDao {

   private SqlSession sqlSession;

   public void setSqlSession(SqlSession sqlSession) {
     this.sqlSession = sqlSession;
   }

   public User getUser(String userId) {
     return (User) sqlSession.selectOne("org.mybatis.spring.sample.mapper.UserMapper.getUser", userId);
   }
 }

保证文件配置了SqlSessionTemplate

  <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
         <constructor-arg name="sqlSessionFactory" ref="sqlSessionFactoryBean"></constructor-arg>
         <constructor-arg name="executorType" value="BATCH"></constructor-arg>
     </bean>

8.2：hibernateDaoSupport对应支持

源码：

 public abstract class SqlSessionDaoSupport extends DaoSupport {

   private SqlSession sqlSession;

   private boolean externalSqlSession;

   public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
     if (!this.externalSqlSession) {
       this.sqlSession = new SqlSessionTemplate(sqlSessionFactory);
     }
   }

   public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {
     this.sqlSession = sqlSessionTemplate;
     this.externalSqlSession = true;
   }

   /**
    * Users should use this method to get a SqlSession to call its statement methods
    * This is SqlSession is managed by spring. Users should not commit/rollback/close it
    * because it will be automatically done.
    *
    * @return Spring managed thread safe SqlSession
    */
   public SqlSession getSqlSession() {
     return this.sqlSession;
   }

   /**
    * {@inheritDoc}
    */
   @Override
   protected void checkDaoConfig() {
     notNull(this.sqlSession, "Property 'sqlSessionFactory' or 'sqlSessionTemplate' are required");
   }

 }

sqlSeesionDaoSupport需要sqlseesiontemplate 或者sqlsessionfactoryBean的直接注入，所以：

 @Repository
 public class EmployeeDao extends SqlSessionDaoSupport {

     @Autowired
     public void setSqlSession(SqlSessionTemplate sqlSession) {
         super.setSqlSessionTemplate(sqlSession);
     }
     public List<Employee> getEmps(){
         SqlSession session = getSqlSession();
         EmployeeMapper mapper = session.getMapper(EmployeeMapper.class);
         List<Employee> emps = mapper.getEmps();
         return emps;
     }

 }

 public class UserDaoImpl extends SqlSessionDaoSupport implements UserDao {
   public User getUser(String userId) {
     return (User) getSqlSession().selectOne("org.mybatis.spring.sample.mapper.UserMapper.getUser", userId);
   }
 }

这里你要确保你得appliacationContext.xml中具有sqlsessiontemplate才能保证注入：

其实你发现没有，EmployeeDao这么复杂，实际上你配置MapperScannerConfigurer 他内步完成的也是这些操作

 @Service
 public class EmployeeService {

     @Autowired
     private EmployeeMapper employeeMapper;

     @Autowired
     EmployeeDao employeeDao;

     /*@Autowired
     private SqlSession sqlSession;*/

     public List<Employee> getEmps() {
         //List<Employee> selectOne = sqlSession.selectOne("com.gitee.dgwcode.mapper.EmployeeMapper.getEmps");
         //EmployeeMapper mapper = sqlSession.getMapper(EmployeeMapper.class);
         //List<Employee> emps = employeeDao.getEmps();
         return employeeMapper.getEmps();
     }

 }