MyBatis3+SpringMVC3

开发环境：

System：windows

WEBBrowser：IE6+、Firefox3+

JavaEE Server：Tomcat5.0.2.8、tomcat6

IDE：eclipse、MyEclipse 8

Database：Mysql

开发依赖库：

JavaEE5、spring 3.0.5、mybatis 3.0.4、myBatis-spring-1.0、junit4.8.2

1、 首先新建一个WebProject 命名为MyBatisForSpring，新建项目时，使用JavaEE5的lib库。然后手动添加需要的jar包，所需jar包如下：

2、 添加spring的监听及springMVC的核心Servlet，web.xml内容，内容如下：

<!-- 加载Spring容器配置 -->
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<!-- 设置Spring容器加载配置文件路径 -->
<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath*:applicationContext-*.xml</param-value>
</context-param>

<!-- 配置Spring核心控制器 -->
<servlet>
    <servlet-name>dispatcher</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/dispatcher.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>*.do</url-pattern>
</servlet-mapping>

<!-- 解决工程编码过滤器 -->
<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>
</filter>

<filter-mapping>
    <filter-name>characterEncodingFilter</filter-name>
    <url-pattern>*-resultmap.xml</value>
                <value>classpath:com/hoo/entity*-mapper.xml</value>
            </list>
        </property>
    </bean>

    <!-- 单独配置一个Mapper； 这种模式就是得给每个mapper接口配置一个bean -->
    <!--
    <bean id="accountMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
        <property name="mapperInterface" value="com.hoo.mapper.AccountMapper" />
        <property name="sqlSessionFactory" ref="sqlSessionFactory" />
    </bean>

    <bean id="companyMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
        <property name="mapperInterface" value="com.hoo.mapper.CompanyMapper" />
        <property name="sqlSessionFactory" ref="sqlSessionFactory" />
    </bean>
     -->

    <!-- 通过扫描的模式，扫描目录在com/hoo/mapper目录下，所有的mapper都继承SqlMapper接口的接口， 这样一个bean就可以了 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.hoo.mapper"/>
        <property name="markerInterface" value="com.hoo.mapper.SqlMapper"/>
    </bean>
</beans>

上面的配置最先配置的是DataSource，这里采用的是jdbc的DataSource；

然后是SqlSessionFactoryBean，这个配置比较关键。SqlSessionFactoryBean需要注入DataSource数据源，其次还要设置configLocation也就是mybatis的xml配置文件路径，完成一些关于mybatis的配置，如settings、mappers、plugin等；

如果使用mapperCannerConfigurer模式，需要设置扫描根路径也就是你的mybatis的mapper接口所在包路径；凡是markerInterface这个接口的子接口都参与到这个扫描，也就是说所有的mapper接口继承这个SqlMapper。

如果你不使用自己的transaction事务，就使用MapperScannerConfigurer来完成SqlSession的打开、关闭和事务的回滚操作。在此期间，出现数据库操作的如何异常都会被转换成DataAccessException，这个异常是一个抽象的类，继承RuntimeException；

5、 SqlMapper内容如下：

package com.hoo.mapper;


public interface SqlMapper {

}

6、 实体类和ResultMap.xml

package com.hoo.entity;

import java.io.Serializable;
import javax.persistence.Entity;

@Entity
public class Account implements Serializable {

    private static final long serialVersionUID = -7970848646314840509L;

    private Integer accountId;
    private Integer status;
    private String username;
    private String passWord;
    private String salt;
    private String email;
    private Integer roleId;

    //getter、setter

    @Override
    public String toString() {
        return this.accountId + "#" + this.status + "#" + this.username +  "#" +
            this.password +  "#" + this.email +  "#" + this.salt + "#" + this.roleId;
    }
}

account-resultmap.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="accountMap">
    <resultMap type="com.hoo.entity.Account" id="accountResultMap">
        <id property="accountId" column="account_id"/>
        <result property="username" column="username"/>
        <result property="password" column="password"/>
        <result property="status" column="status"/>
    </resultMap>
</mapper>

7、 在src目录中添加applicationContext-beans.xml内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    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-3.0.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-3.0.xsd"
    <!-- 注解探测器 ， 在JUnit测试的时候需要-->
    <context:component-scan base-package="com.hoo"/>

</beans>

这里配置bean对象，一些不能用annotation注解的对象就可以配置在这里

8、 在src目录中添加mybatis.xml，内容如下：

<?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>
    <!-- 别名 -->
    <typeAliases>
        <typeAlias type="com.hoo.entity.Account" alias="account"/>
    </typeAliases>
</configuration>

在这个文件放置一些全局性的配置，如handler、objectFactory、plugin、以及mappers的映射路径（由于在applicationContext-common中的SqlSessionFactoryBean有配置mapper的location，这里就不需要配置）等

9、 AccountMapper接口，内容如下：

package com.hoo.mapper;

import java.util.List;
import org.apache.ibatis.annotations.Select;
import com.hoo.entity.Account;


public interface AccountMapper extends SqlMapper {

    public List<Account> getAllAccount();

    public Account getAccount();

    public Account getAccountById(String id);

    public Account getAccountByNames(String spring);

    @Select("select * from account where username = #{name}")
    public Account getAccountByName(String name);

    public void addAccount(Account account);

    public void editAccount(Account account);

    public void removeAccount(int id);
}

这个接口我们不需要实现，由mybatis帮助我们实现，我们通过mapper文件配置sql语句即可完成接口的实现。然后这个接口需要继承SqlMapper接口，不然在其他地方就不能从Spring容器中拿到这个mapper接口，也就是说当我们注入这个接口的时候将会失败。

当然，你不继承这个接口也可以。那就是你需要给买个mapper配置一个bean。配置方法如下：

<bean id="accountMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
    <property name="mapperInterface" value="com.hoo.mapper.AccountMapper" />
    <property name="sqlSessionFactory" ref="sqlSessionFactory" />
</bean>

这里的MapperFactoryBean可以帮助我们完成Session的打开、关闭等操作

10、 在com.hoo.mapper也就是在AccountMapper接口的同一个包下，添加account-mapper.xml，内容如下：

<?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">
<!-- namespace和定义的Mapper接口对应，并实现其中的方法 -->
<mapper namespace="com.hoo.mapper.AccountMapper">
    <!-- id和mapper接口中的方法名对应，resultType使用mybatis.xml中的别名 -->
    <select id="getAccount" resultType="account">
        <![CDATA[
            select * from account limit 1
        ]]>
    </select>

    <select id="getAllAccount" resultType="list" resultMap="accountResultMap">
        <![CDATA[
            select * from account
        ]]>
    </select>

    <!-- accountResultMap是account-resultmap.xml中定义的resultmap -->
    <select id="getAccountById" parameterType="string" resultType="com.hoo.entity.Account" resultMap="accountResultMap">
        <![CDATA[
            select * from account where account_id = #{id}
        ]]>
    </select>

    <!-- accountMap.accountResultMap是account-resultmap.xml中定义的resultmap，通过namespace.id找到 -->
    <select id="getAccountByNames" parameterType="string" resultMap="accountMap.accountResultMap">
        <![CDATA[
            select * from account where username = #{name}
        ]]>
    </select>

    <sql id="user_name_pwd">
        username, password
    </sql>

    <!-- 自动生成id策略 -->
    <insert id="addAccount" useGeneratedKeys="true" keyProperty="account_id" parameterType="account">
        insert into account(account_id, status, username, password)
        values(#{accountId}, #{status}, #{username}, #{password})
    </insert>

    <!-- 根据selecTKEy语句生成主键 -->
    <insert id="addAccount4Key" parameterType="account">
        <selectKey keyProperty="account_id" order="BEFORE" resultType="int">
            select cast(random() * 10000 as Integer) a from #Tab
        </selectKey>
        insert into account(account_id, status, username, password)
        values(#{accountId}, #{status}, #{username}, #{password})
    </insert>

    <update id="editAccount" parameterType="account">
        update account set
        status = #{status},
        username = #{username},
        password = #{password}
        where account_id = #{accountId}
    </update>

    <delete id="removeAccount" parameterType="int">
        delete from account where account_id = #{id}
    </delete>
</mapper>

上面的namespace和定义接口类路径对应，所有的sql语句，如select、insert、delete、update的id和方法名称对应。关于更多MyBatis内容的讲解，这里就不赘述的。这里只完成整合！如果你不懂可以去阅读其他关于MyBatis的资料。

11、 为了测试发布，这里使用junit和spring官方提供的spring-test.jar，完成spring框架整合的测试，代码如下：

package com.hoo.mapper;

import java.util.List;
import javax.inject.Inject;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit38.AbstractJUnit38SprinGContextTests;
import com.hoo.entity.Account;



@ContextConfiguration("classpath:applicationContext-*.xml")
public class AccountMapperTest extends AbstractJUnit38SpringContextTests {

    @Inject
    //@Named("accountMapper")
    private AccountMapper mapper;

    public void testGetAccount() {
        System.out.println(mapper.getAccount());
    }

    public void testGetAccountById() {
        System.out.println(mapper.getAccountById("28"));
    }

    public void testGetAccountByName() {
        System.out.println(mapper.getAccountByName("user"));
    }

    public void testGetAccountByNames() {
        System.out.println(mapper.getAccountByNames("user"));
    }

    public void testAdd() {
        Account account = new Account();
        account.setEmail("temp@155.com");
        account.setPassword("abc");
        account.setRoleId(1);
        account.setSalt("ss");
        account.setStatus(0);
        account.setUsername("Jack");
        mapper.addAccount(account);
    }

    public void testEditAccount() {
        Account acc = mapper.getAccountByNames("Jack");
        System.out.println(acc);
        acc.setUsername("Zhangsan");
        acc.setPassword("123123");
        mapper.editAccount(acc);
        System.out.println(mapper.getAccountById(acc.getAccountId() + ""));
    }

    public void testRemoveAccount() {
        Account acc = mapper.getAccountByNames("Jack");
        mapper.removeAccount(acc.getAccountId());
        System.out.println(mapper.getAccountByNames("Jack"));
    }

    public void testAccountList() {
        List<Account> acc = mapper.getAllAccount();
        System.out.println(acc.size());
        System.out.println(acc);
    }
}

这里的注入并没有使用@Autowired、@Resource、@Qualifier注入，而是使用@Inject、@Named注入方式，Inject注入是jsR330的标准注入方式；而不局限于某个产品，使用于多个产品的使用，推荐使用这种方式；运行后，没有发现问题，就可以继续后续的编码工作了。

12、 定义AccountDao接口及实现代码，代码如下：

package com.hoo.dao;

import java.util.List;
import org.springframework.dao.DataAccessException;


public interface AccountDao<T> {


    public boolean addAccount(T entity) throws DataAccessException;


    public T getAccount(Integer id) throws DataAccessException;


    public List<T> getList() throws DataAccessException;
}

接口实现

package com.hoo.dao.impl;

import java.util.List;
import javax.inject.Inject;
import org.springframework.dao.DataAccessException;
import org.springframework.stereotype.Repository;
import com.hoo.dao.AccountDao;
import com.hoo.entity.Account;
import com.hoo.mapper.AccountMapper;


@SuppressWarnings("unchecked")
@Repository
public class AccountDaoImpl<T extends Account> implements AccountDao<T> {

    @Inject
    private AccountMapper mapper;

    public boolean addAccount(T entity) throws DataAccessException {
        boolean flag = false;
        try {
            mapper.addAccount(entity);
            flag = true;
        } catch (DataAccessException e) {
            flag = false;
            throw e;
        }
        return flag;
    }

    public T getAccount(Integer id) throws DataAccessException {
        T entity = null;
        try {
            entity = (T) mapper.getAccountById(String.valueOf(id));
        } catch (DataAccessException e) {
            throw e;
        }
        return entity;
    }

    public List<T> getList() throws DataAccessException {
        return (List<T>) mapper.getAllAccount();
    }
}

13、 服务层AccountBiz接口及实现代码

接口：

package com.hoo.biz;

import java.util.List;
import org.springframework.dao.DataAccessException;


public interface AccountBiz<T> {

    public boolean addAccount(T entity) throws DataAccessException;


    public T getAccount(Integer id) throws DataAccessException;


    public List<T> getList() throws DataAccessException;
}

实现代码：

package com.hoo.biz.impl;

import java.util.List;
import javax.inject.Inject;
import org.springframework.dao.DataAccessException;
import org.springframework.stereotype.Service;
import com.hoo.biz.AccountBiz;
import com.hoo.dao.AccountDao;
import com.hoo.entity.Account;
import com.hoo.exception.BizException;


//@Component
@Service
public class AccountBizImpl<T extends Account> implements AccountBiz<T> {

    @Inject
    private AccountDao<T> dao;

    public boolean addAccount(T entity) throws DataAccessException {
        if (entity == null) {
            throw new BizException(Account.class.getName() + "对象参数信息为Empty！");
        }
        return dao.addAccount(entity);
    }

    public T getAccount(Integer id) throws DataAccessException {
        return dao.getAccount(id);
    }

    public List<T> getList() throws DataAccessException {
        return dao.getList();
    }
}

上面用到了一个自定义的异常信息，代码如下：

package com.hoo.exception;

import org.springframework.dao.DataAccessException;


public class BizException extends DataAccessException {


    private static final long serialVersionUID = 1L;

    public BizException(String msg) {
        super(msg);
    }

    public BizException(String msg, Throwable cause) {
        super(msg, cause);
    }
}

这里只是简单的继承，如果还有其他的异常业务或需求可以进行具体的实现

14、 springmvc的控制器，AccountController代码如下：

package com.hoo.controller;

import javax.inject.Inject;
import javax.servlet.http.httpservletRequest;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import com.hoo.biz.AccountBiz;
import com.hoo.entity.Account;


@Controller
@RequestMapping("/account")
public class AccountController {

    @Inject
    private AccountBiz<Account> biz;

    @RequestMapping("/add")
    public String add(Account acc) {
        System.out.println(acc);
        biz.addAccount(acc);
        return "redirect:/account/list.do";
    }

    @RequestMapping("/get")
    public String get(Integer id, Model model) {
        System.out.println("##ID:" + id);
        model.addAttribute(biz.getAccount(id));
        return "/show.jsp";
    }

    @RequestMapping("/list")
    public String list(Model model) {
        model.addAttribute("list", biz.getList());
        return "/list.jsp";
    }

    @ExceptionHandler(Exception.class)
    public String exception(Exception e, HttpServletRequest request) {
        //e.printStackTrace();
        request.setAttribute("exception", e);
        return "/error.jsp";
    }
}

15、 基本页面代码

index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%   1:     2: String path = request.getContextPath();   3: String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">

    <title>MyBatis 整合  Spring 3.0.5</title>
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
  </head>

  <body>
          <h3>MyBatis 3.0.4  整合  Spring 3.0.5</h3>
        <a href="account/list.do">查询所有</a><br/>
        <a href="account/add.do?username=abcdef&password=123132&status=2">添加</a><br/>
        <a href="account/get.do?id=25">查询</a><br/>
  </body>
</html>

List.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%   1:     2: String path = request.getContextPath();   3: String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">

    <title>all Account Result</title>

    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
  </head>

  <body>
        <c:forEach items="${list}" var="data">
            id: ${data.accountId }---name: ${data.username }---password: ${data.password }<hr/>
        </c:forEach>
  </body>
</html>

show.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%   1:     2: String path = request.getContextPath();   3: String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">

    <title>show Account</title>

    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
  </head>

  <body>
        ${account }<br/>
        ${account.username }#${account.accountId }
  </body>
</html>

error.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %>  <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html>   <head>     <base href="<%=basePath%>">          <title>Error Page</title>          <meta http-equiv="pragma" content="no-cache">     <meta http-equiv="cache-control" content="no-cache">     <meta http-equiv="expires" content="0">         <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">     <meta http-equiv="description" content="This is my page">   </head>      <body>     <H2>Exception: ${exception }</H2>      <a href="javascript:document.getElementById('show').style.display = 'block';void(0);">         详细信息     </a>      <div id="show" style="color: red; display: none;">         <% Exception ex = (Exception)request.getAttribute("exception"); %>                   <% ex.printStackTrace(new java.io.PrintWriter(out)); %>     </div>    </body> </html>

16、 以上就基本上完成了整个Spring+SpringMVC+MyBatis的整合了。如果你想添加事务管理，得在applicationContext-common.xml中加入如下配置：

<!-- 配置事务管理器，注意这里的dataSource和SqlSessionFactoryBean的dataSource要一致，不然事务就没有作用了 -->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource" />
</bean>

同时还需要加入aspectjweaver.jar这个jar包；

注意的是：Jdbc的TransactionManager不支持事务隔离级别，我在整个地方加入其它的TransactionManager，增加对transaction的隔离级别都尝试失败！

也许可以用于jpa、jdo、jta这方面的东西。不知道大家对MyBatis的事务是怎么处理的？

17、 对Dao进行扩展封装，运用SqlSessionDaoSupport进行模板的扩展或运用：

BaseDao代码如下：

package com.hoo.dao;

import java.util.List;


public interface BaseDao<T> {

    public boolean add(String claSSMethod, T entity) throws Exception;

    public boolean edit(String classMethod, T entity) throws Exception;

    public boolean remove(String classMethod, T entity) throws Exception;

    public T get(String classMethod, T entity) throws Exception;

    public List<T> getAll(String classMethod) throws Exception;
}

实现类代码：

package com.hoo.dao.impl;

import java.util.ArrayList;
import java.util.List;
import javax.inject.Inject;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.support.SqlSessionDaoSupport;
import org.springframework.stereotype.Repository;
import com.hoo.dao.BaseDao;


@Repository
@SuppressWarnings({ "unchecked", "unused" })
public class BaseDaoImpl<T extends Object> extends SqlSessionDaoSupport implements BaseDao<T> {

    @Inject
    private SqlSessionFactory sqlSessionFactory;

    public boolean add(String classMethod, T entity) throws Exception {
        boolean flag = false;
        try {
            flag = this.getSqlSession().insert(classMethod, entity) > 0 ? true : false;
        } catch (Exception e) {
            flag = false;
            throw e;
        }
        return flag;
    }

    public boolean edit(String classMethod, T entity) throws Exception {
        boolean flag = false;
        try {
            flag = this.getSqlSession().update(classMethod, entity) > 0 ? true : false;
        } catch (Exception e) {
            flag = false;
            throw e;
        }
        return flag;
    }

    public T get(String classMethod, T entity) throws Exception {
        T result = null;
        try {
            result = (T) this.getSqlSession().selectOne(classMethod, entity);
        } catch (Exception e) {
            throw e;
        }
        return result;
    }

    public List<T> getAll(String classMethod) throws Exception {
        List<T> result = new ArrayList<T>();
        try {
            result = this.getSqlSession().selectList(classMethod);
        } catch (Exception e) {
            throw e;
        }
        return result;
    }

    public boolean remove(String classMethod, T entity) throws Exception {
        boolean flag = false;
        try {
            flag = this.getSqlSession().delete(classMethod, entity) > 0 ? true : false;
        } catch (Exception e) {
            flag = false;
            throw e;
        }
        return flag;
    }
}

值得说明的是，这个类继承了SqlSessionDaoSupport，它需要我们帮助它注入SqlSessionFactory或是SqlSessionTemplate，如果两者都被注入将忽略SqlSessionFactory属性，使用SqlSessionTemplate模板。

继承SqlSessionDaoSupport后，可以拿到SqlSession完成数据库的操作；

18、 对Dao进行扩展封装，运用SqlSessionTemplate进行模板的扩展或运用：

首先看看这个组件中运用的一个Mapper的基类接口：

package com.hoo.mapper;

import java.util.List;
import org.springframework.dao.DataAccessException;


public interface BaseSqlMapper<T> extends SqlMapper {

    public void add(T entity) throws DataAccessException;

    public void edit(T entity) throws DataAccessException;

    public void remvoe(T entity) throws DataAccessException;

    public T get(T entity) throws DataAccessException;

    public List<T> getList(T entity) throws DataAccessException;
}

该接口继承SqlMapper接口，但是该接口没有MyBatis的mapper实现。需要我们自己的业务mapper继承这个接口，完成上面的方法的实现。

看看继承SqlSessionTemplate的BaseMapperDao代码：

package com.hoo.dao;

import java.util.List;
import com.hoo.mapper.BaseSqlMapper;


public interface BaseMapperDao<T> {

    @SuppressWarnings("unchecked")
    public void setMapperClass(Class<? extends BaseSqlMapper> mapperClass);

    public boolean add(T entity) throws Exception;

    public boolean edit(T entity) throws Exception;

    public boolean remove(T entity) throws Exception;

    public T get(T entity) throws Exception;

    public List<T> getAll() throws Exception;
}

package com.hoo.dao.impl;

import java.util.List;
import javax.inject.Inject;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionTemplate;
import org.springframework.stereotype.Repository;
import com.hoo.dao.BaseMapperDao;
import com.hoo.mapper.BaseSqlMapper;


@SuppressWarnings("unchecked")
@Repository
public class BaseMapperDaoImpl<T> extends SqlSessionTemplate implements BaseMapperDao<T> {

    @Inject
    public BaseMapperDaoImpl(SqlSessionFactory sqlSessionFactory) {
        super(sqlSessionFactory);
    }

    private Class<? extends BaseSqlMapper> mapperClass;

    public void setMapperClass(Class<? extends BaseSqlMapper> mapperClass) {
        this.mapperClass = mapperClass;
    }

    private BaseSqlMapper<T> getMapper() {
        return this.getMapper(mapperClass);
    }

    public boolean add(T entity) throws Exception {
        boolean flag = false;
        try {
            this.getMapper().add(entity);
            flag = true;
        } catch (Exception e) {
            flag = false;
            throw e;
        }
        return flag;
    }

    public boolean edit(T entity) throws Exception {
        boolean flag = false;
        try {
            this.getMapper().edit(entity);
            flag = true;
        } catch (Exception e) {
            flag = false;
            throw e;
        }
        return flag;
    }

    public T get(T entity) throws Exception {
        return this.getMapper().get(entity);
    }

    public List<T> getAll() throws Exception {
        return this.getMapper().getList(null);
    }

    public boolean remove(T entity) throws Exception {
        boolean flag = false;
        try {
            this.getMapper().remvoe(entity);
            flag = true;
        } catch (Exception e) {
            flag = false;
            throw e;
        }
        return flag;
    }
}

上面这个类继承了SqlSessionTemplate，这个类需要提供一个构造函数。这里提供的是SqlSessionFactory的构造函数，通过该函数注入SqlSessionFactory即可完成数据库操作；

例外的是这个类还有一个关键属性mapperClass，这个class需要是BaseSqlMapper接口或是子接口，然后通过SqlSessionTemplate模板获得当前设置的Class的Mapper对象，完成数据库操作。

该类的测试代码：

@ContextConfiguration("classpath:applicationContext-*.xml")
public class BaseMapperDaoImplTest extends AbstractJUnit38SpringContextTests {

    @Inject
    private BaseMapperDao<Company> dao;

    public void init() {
        dao.setMapperClass(CompanyMapper.class);
    }

    public void testGet() throws Exception {
        init();
        Company c = new Company();
        c.setCompanyId(4);
        System.out.println(dao.get(c));
    }

    public void testAdd() throws Exception {
        init();
        Company c = new Company();
        c.setAddress("北京中关村");
        c.setName("beijin");
        System.out.println(dao.add(c));
    }
}

一般情况下，你可以在一个Dao中注入BaseMapperDao，紧跟着需要设置MapperClass。只有设置了MapperClass后，BaseMapperDao才能获取对应mapper，完成相关的数据库操作。当然你可以在这个Dao中将SqlSessionTemplate、SqlSession暴露出来，当BaseMapperDao的方法不够用，可以进行扩展。