（三）使用XML配置SQL映射器

SqlSessionFactoryUtil.java

 package com.javaxk.util;

 import java.io.IOException;
 import java.io.InputStream;

 import org.apache.ibatis.io.Resources;
 import org.apache.ibatis.session.SqlSession;
 import org.apache.ibatis.session.SqlSessionFactory;
 import org.apache.ibatis.session.SqlSessionFactoryBuilder;

 public class SqlSessionFactoryUtil {

     private static SqlSessionFactory sqlSessionFactory;

     public static SqlSessionFactory getSqlSessinFactory() {

         if (sqlSessionFactory == null) {

             String resource = "mybatis-config.xml";
             InputStream inputStream = null;
             try {
                 inputStream = Resources.getResourceAsStream(resource);
             } catch (IOException e) {
                 // TODO Auto-generated catch block
                 e.printStackTrace();
             }
             sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream);
         }

         return sqlSessionFactory;
     }

     public static SqlSession openSession() {
         return getSqlSessinFactory().openSession();
     }

 }

Student.java

 package com.javaxk.model;

 public class Student {

     private int id;
     private String name;
     private int age;

     public Student() {
         super();
     }

     public Student(int id, String name, int age) {
         super();
         this.id = id;
         this.name = name;
         this.age = age;
     }

     public Student(String name, int age) {
         super();
         this.name = name;
         this.age = age;
     }
     public int getId() {
         return id;
     }
     public void setId(int id) {
         this.id = id;
     }
     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public int getAge() {
         return age;
     }
     public void setAge(int age) {
         this.age = age;
     }

     @Override
     public String toString() {
         return "Student [id=" + id + ", name=" + name + ", age=" + age + "]";
     }

 }

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>
     <!-- <properties resource="jdbc.properties"/> -->

     <properties>
         <property name="jdbc.driverClassName" value="com.mysql.jdbc.Driver"/>
         <property name="jdbc.url" value="jdbc:mysql://localhost:3306/db_mybatis?characterEncoding=utf-8"/>
         <property name="jdbc.username" value="root"/>
         <property name="jdbc.password" value="root"/>
     </properties>

     <!--
     <typeAliases>
         <typeAlias alias="Student" type="com.javaxk.model.Student"/>
     </typeAliases>
      -->

      <typeAliases>
          <package name="com.javaxk.model"/>
      </typeAliases>

     <environments default="development">

         <environment id="development">
             <transactionManager type="JDBC" />
             <dataSource type="POOLED">
                 <property name="driver" value="${jdbc.driverClassName}" />
                 <property name="url" value="${jdbc.url}" />
                 <property name="username" value="${jdbc.username}" />
                 <property name="password" value="${jdbc.password}" />
             </dataSource>
         </environment>

         <environment id="test">
             <transactionManager type="JDBC" />
             <dataSource type="POOLED">
                 <property name="driver" value="${jdbc.driverClassName}" />
                 <property name="url" value="${jdbc.url}" />
                 <property name="username" value="${jdbc.username}" />
                 <property name="password" value="${jdbc.password}" />
             </dataSource>
         </environment>

     </environments>

     <mappers>
     <!--
         <mapper resource="com/javaxk/mappers/StudentMapper.xml" />
     -->
         <package name="com.javaxk.mappers"/>
     </mappers>
 </configuration>

StudentMapper.java

 package com.javaxk.mappers;

 import java.util.List;

 import com.javaxk.model.Student;

 public interface StudentMapper {

     public int add(Student student);

     public int update(Student student);

     public int delete(Integer id);

     public Student findById(Integer id);

     public List<Student> find();

 }

StudentMapper.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="com.javaxk.mappers.StudentMapper">

     <resultMap type="Student" id="StudentResult">
         <id property="id" column="id"/>
         <result property="name" column="name"/>
         <result property="age" column="age"/>
     </resultMap>

     <insert id="add" parameterType="Student"  >
         insert into t_student values(null,#{name},#{age})
     </insert>

     <update id="update" parameterType="Student">
         update t_student set name=#{name},age=#{age} where id=#{id}
     </update>

     <delete id="delete" parameterType="Integer">
         delete from t_student where id=#{id}
     </delete>

     <select id="findById" parameterType="Integer" resultType="Student">
         select * from t_student where id=#{id}
     </select>

     <select id="find" resultMap="StudentResult">
         select * from t_student
     </select>

 </mapper> 

所有的主测试类都在JUtil的测试方法前后中调用

 private static Logger logger = Logger.getLogger(StudentTest2.class);
      private SqlSession sqlSession = null;
      private StudentMapper studentMapper = null;

      /**
       * 测试方法前调用
       * @throws Exception
       */
     @Before
     public void setUp() throws Exception {
         sqlSession = SqlSessionFactoryUtil.openSession();
         studentMapper = sqlSession.getMapper(StudentMapper.class);
     }

     /**
      * 测试方法后调用
      * @throws Exception
      */
     @After
     public void tearDown() throws Exception {
         sqlSession.close();
     }

第一节：insert映射语句

添加映射配置文件

     <insert id="add" parameterType="Student"  >
         insert into t_student values(null,#{name},#{age})
     </insert>

     @Test
     public void testAdd() {
         logger.info("添加学生");
         Student student = new Student("小宁" ,88);
         studentMapper.add(student);
         sqlSession.commit();

     }

第二节：update映射语句

     <update id="update" parameterType="Student">
         update t_student set name=#{name},age=#{age} where id=#{id}
     </update>

     @Test
     public void testUpdate() {
         logger.info("更新学生");
         Student student = new Student(20,"小宁22",99);
         studentMapper.update(student);
         sqlSession.commit();
     }

第三节：delete映射语句

     <delete id="delete" parameterType="Integer">
         delete from t_student where id=#{id}
     </delete>

     @Test
     public void testDelete() {
         logger.info("删除学生");
         studentMapper.delete(20);
         sqlSession.commit();
     }

第四节：select映射语句

（1）通过ID查找学生

     <select id="findById" parameterType="Integer" resultType="Student">
         select * from t_student where id=#{id}
     </select>

     @Test
     public void testFindById() {
         logger.info("通过ID查找学生");
         Student student=studentMapper.findById(1);
         System.out.println(student);
     }

（2）查找所有学生

     <resultMap type="Student" id="StudentResult">
         <id property="id" column="id"/>
         <result property="name" column="name"/>
         <result property="age" column="age"/>
     </resultMap>

     <select id="find" resultMap="StudentResult">
         select * from t_student
     </select>

     @Test
     public void testFind() {
         logger.info("查找所有学生");
         List<Student> studentlist = studentMapper.find();
         for (Student s : studentlist) {
             System.out.println(s);
         }
     }