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();
    }

}