（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);
        }
    }