使用映射接口实现数据库的操作

mybatis-config.xml
<?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>
       <typeAliases>  
           <!--这里给实体类取别名，方便在mapper配置文件中使用-->  
          <package name="cn.bdqn.pojo"/>
       </typeAliases>  
</configuration>

applicationContext-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:aop="http://www.springframework.org/schema/aop"
     xmlns:tx="http://www.springframework.org/schema/tx"
     xmlns:context="http://www.springframework.org/schema/context"
     xsi:schemaLocation="
     http://www.springframework.org/schema/beans 
     http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
     http://www.springframework.org/schema/tx
     http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
     http://www.springframework.org/schema/aop 
     http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
     http://www.springframework.org/schema/context
     http://www.springframework.org/schema/context/spring-context-3.0.xsd">     

    <!-- 读取jdbc配置文件 -->
    <context:property-placeholder location="classpath:jdbc.properties"/>
    
    <!-- JNDI获取数据源(使用dbcp连接池) -->  
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close" scope="singleton">
        <property name="driverClassName" value="${driverClassName}" />  
           <property name="url" value="${url}" />  
           <property name="username" value="${username}" />  
           <property name="password" value="${password}" />
    </bean>
    
    <!-- 事务管理 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    
    <!-- 配置mybitas SqlSessionFactoryBean-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
    </bean>
    
    <!-- Dao配置 -->
    <bean id="employeeMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
        <property name="mapperInterface" value="cn.bdqn.dao.EmployeeMapper"/>
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>
    
    <!--MapperScannerConfigurer Mybatis-Spring 会自动为我们注册Mapper对应的MapperFactoryBean对象 -->
    <!-- <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">   -->
        <!-- Mapper接口所在包名，Spring会自动查找其下的Mapper -->  
              <!-- <property name="basePackage" value="cn.jbit.dao" />  
       </bean> -->
    <!-- service 配置 -->
    <bean id="employeeService" class="cn.bdqn.service.impl.EmployeeServieImpl">
        <property name="employeeMapper" ref="employeeMapper"/>
    </bean>
    <!-- spring可以自动去扫描base-pack下面或者子包下面的java文件，
                若扫描到有@Component @Controller@Service等这些注解的类，则把这些类注册为bean-->       
    <!--  <context:component-scan base-package="cn.jbit.service" />   -->   
     
    
 </beans>

EmployeeMapper

public interface EmployeeMapper {
    
    //实现根据部门查询出该部门下的员工信息
    public List<Employee> getEmployeeListByDepId(Department department);
    
    //实现查询员工详细信息的功能
    public Employee getEmployeeById(Employee employee);
}

EmployeeMapper.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="cn.bdqn.dao.EmployeeMapper">
    //resultMap  为了显示出要展现的（去掉不想显示出来的东西比如密码。。。）column对应到数据库列名
　　//type是要显示的类的属性的类   property就是Employee中的属性
　　//resultMap不能喝resultType同时使用

    <resultMap type="Employee" id="employeeResult">
        <result property="id" column="id"/>
        <result property="sn" column="sn"/>
        <result property="name" column="name"/>
        <result property="depName" column="depName"/>
    </resultMap>
    //下面的resultMap引用上面的resultMap
    <select id="getEmployeeById" parameterType="Employee" resultMap="employeeResult">
        select e.*,d.depName as depName from employee e,department d  
            where e.id = #{id} and e.depId = d.id
    </select>
    
    <select id="getEmployeeListByDepId" parameterType="Department" resultMap="employeeResult">
        select e.*,d.depName as depName from employee e,department d  
            where  e.depId = d.id
            <if test="id != null">
                and e.depId = #{id}
            </if>
    </select>

</mapper>

Department .java

public class Department {
    private Integer id;
    private String depName;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getDepName() {
        return depName;
    }
    public void setDepName(String depName) {
        this.depName = depName;
    }
    
}

Employee .java

public class Employee {
    private Integer id;
    private String sn;
    private String name;
    private String gender;
    private Integer depId;
    private String depName;
    
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getSn() {
        return sn;
    }
    public void setSn(String sn) {
        this.sn = sn;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getGender() {
        return gender;
    }
    public void setGender(String gender) {
        this.gender = gender;
    }
    public Integer getDepId() {
        return depId;
    }
    public void setDepId(Integer depId) {
        this.depId = depId;
    }
    public String getDepName() {
        return depName;
    }
    public void setDepName(String depName) {
        this.depName = depName;
    }
}

service--EmployeeService.java

public interface EmployeeService {
    //实现根据部门查询出该部门下的员工信息
    public List<Employee> getEmployeeListByDepId(Department department);
    
    //实现查询员工详细信息的功能
    public Employee getEmployeeById(Employee employee);
}

EmployeeServieImpl 

public class EmployeeServieImpl implements EmployeeService{
    
    @Resource
    private EmployeeMapper employeeMapper;
    
    public EmployeeMapper getEmployeeMapper() {
        return employeeMapper;
    }

    public void setEmployeeMapper(EmployeeMapper employeeMapper) {
        this.employeeMapper = employeeMapper;
    }

    @Override
    public List<Employee> getEmployeeListByDepId(Department department) {
        // TODO Auto-generated method stub
        return employeeMapper.getEmployeeListByDepId(department);
    }

    @Override
    public Employee getEmployeeById(Employee employee) {
        // TODO Auto-generated method stub
        return employeeMapper.getEmployeeById(employee);
    }

}

测试类

public class EmployeeServiceTest {
    
    private Logger logger = Logger.getLogger(EmployeeServiceTest.class);
    protected ApplicationContext ctx = null;
    private EmployeeService employeeService;
    @Before
    public void setUp() throws Exception{
        ctx = new ClassPathXmlApplicationContext("applicationContext-mybatis.xml");
        employeeService = (EmployeeService)ctx.getBean("employeeService");
    }
    
    @Test
    public void getEmployeeListByDepIdTest() {
        
         List<Employee> list = null;
         Department department = new Department();
         department.setId(2);
         list  = employeeService.getEmployeeListByDepId(department);
         if(null != list && list.size() > 0){
             for(Employee _employee : list){
                 logger.debug("getEmployeeListByDepIdTest---> " + _employee.getName());
             }
         }else{
             logger.debug("getEmployeeListByDepIdTest---> 该部门没有员工数据！");
         }
    }
    
    @Test
    public void getEmployeeByIdTest() {
        
        Employee employee = new Employee();
        employee.setId(2);
        Employee _employee = null;
        _employee  = employeeService.getEmployeeById(employee);
        if(null != _employee ){
            logger.debug("getEmployeeByIdTest---> " + _employee.getName());
        }else{
            logger.debug("getEmployeeByIdTest---> 没有员工数据！");
        }
    }

}