Mybatis入门crud

学习参考自NAYNEHC博客园

该框架使用方法有很多，当前使用 [javaBean]Mapper.xml  简单映射接口实现增删改查的方法：

配置mybatis有---<configuration>

                                     -------><properties>属性文件配置，如数据库，日记记录

                                      -------><environments>配置环境（可多个，如各种数据库厂商）

                                      -----------------------------><environment>其中一个

                                      --------------------------------------------------><transactionManager>事务管理

                                      --------------------------------------------------><dataSource>配置数据源

                                       -------><mappers>映射注册配置（可多个）

                                        ----------------------><mapper>一个映射类位置

配置映射类 [javaBean]Mapper.xml，对数据库sql语句映射 如：
  

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    <insert id="insertStudent">
        insert into student(sno,sname,score) values(#{sno},#{sname},#{score})
    </insert>

具体实现例子如下：

1、结构目录，需要导入mybatis、mysql的jar包

2、mybatis.cfg.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>
	<!-- 引入外部文件 -->
	<properties resource="mysql.properties"/>
	
	<environments default="develpment">
		<environment id="develpment">
			<transactionManager type="JDBC"/>
			
			<dataSource type="POOLED">
				<property name="driver" value="${driver}"/>
				<property name="url" value="${url}"/>
				<property name="username" value="${user}"/>
				<property name="password" value="${password}"/>
			</dataSource>
		</environment>
	
	</environments>
	
	<mappers>
		<mapper resource="com/crud/mapper/StudentMapper.xml"/>
		<!-- <package name="com/crud/mapper"/> -->
	</mappers>
	
</configuration>

3、mysql.properties

4、Student实体类

package com.crud.model;

public class Student {

	private int sno;
	private String sname;
	private double score;
	
	@Override
	public String toString() {
		return "Student [sno=" + sno + ", sname=" + sname + ", score=" + score + "]";
	}
	public Student() {
		super();
	}
	public Student(int sno, String sname, double score) {
		super();
		this.sno = sno;
		this.sname = sname;
		this.score = score;
	}
	public int getSno() {
		return sno;
	}
	public void setSno(int sno) {
		this.sno = sno;
	}
	public String getSname() {
		return sname;
	}
	public void setSname(String sname) {
		this.sname = sname;
	}
	public double getScore() {
		return score;
	}
	public void setScore(double score) {
		this.score = score;
	}
}

5、mapper包下的crud方法接口类，实现类、对象的sql映射文件

package com.crud.mapper;

import java.util.List;

import com.crud.model.Student;

public interface InterStudentMapper {

	public int insertStudent(Student student);
	
	public int deleteStudent(int sno);
	
	public int updateStudent(Student student);
	
	public Student selectStudent(int sno);
	
	public List<Student> selectAllStudent();
}

package com.crud.mapper;

import java.util.List;

import org.apache.ibatis.session.SqlSession;

import com.crud.model.Student;
import com.crud.tool.DBtool;

public class StudentMapperImpl implements InterStudentMapper {

	@Override
	public int insertStudent(Student student) {
		SqlSession sqlSession=DBtool.getSqlSession();
		InterStudentMapper mapper=sqlSession.getMapper(InterStudentMapper.class);
		try{	//线程不安全类型，放在方法体中。
			mapper.insertStudent(student);
			sqlSession.commit();
			System.out.println("had inserted:"+student);
		}catch(Exception e){
			e.printStackTrace();
			sqlSession.rollback();
			return 1;
		}finally{
			sqlSession.close();
		}
		return 0;
	}

	@Override
	public int deleteStudent(int sno) {
		SqlSession sqlSession=DBtool.getSqlSession();
		InterStudentMapper mapper=sqlSession.getMapper(InterStudentMapper.class);
		try{
			mapper.deleteStudent(sno);
			sqlSession.commit();
			System.out.println("had deleted:"+sno);
		}catch(Exception e){
			e.printStackTrace();
			sqlSession.rollback();
			return 1;
		}finally{
			sqlSession.close();
		}
		return 0;
	}

	@Override
	public int updateStudent(Student student) {
		SqlSession sqlSession=DBtool.getSqlSession();
		InterStudentMapper mapper=sqlSession.getMapper(InterStudentMapper.class);
		try{
			Student before=mapper.selectStudent(student.getSno());
			mapper.updateStudent(student);
			sqlSession.commit();
			Student after=mapper.selectStudent(student.getSno());
			sqlSession.commit();
			System.out.println(before+" had changed:"+after);
		}catch(Exception e){
			e.printStackTrace();
			sqlSession.rollback();
			return 1;
		}finally{
			sqlSession.close();
		}
		return 0;
	}

	@Override
	public Student selectStudent(int sno) {
		Student stu=null;
		SqlSession sqlSession=DBtool.getSqlSession();
		InterStudentMapper mapper=sqlSession.getMapper(InterStudentMapper.class);
		try{
			stu=mapper.selectStudent(sno);
			sqlSession.commit();
		}catch(Exception e){
			e.printStackTrace();
			sqlSession.rollback();
			return null;
		}finally{
			sqlSession.close();
		}
		return stu;
	}

	@Override
	public List<Student> selectAllStudent() {
		List<Student> list=null;
		SqlSession sqlSession=DBtool.getSqlSession();
		InterStudentMapper mapper=sqlSession.getMapper(InterStudentMapper.class);
		try{
			list=mapper.selectAllStudent();
			sqlSession.commit();
		}catch(Exception e){
			e.printStackTrace();
			sqlSession.rollback();
			return null;
		}finally{
			sqlSession.close();
		}
		return list;
		
	}

}

<?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE mapper PUBLIC "-//mybatis.org/DTD Mapper 3.0" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!-- 对接口方法进行映射 -->
<mapper namespace="com.crud.mapper.InterStudentMapper">
	
	<!-- 自定义resultMap结果集类型 -->
	<resultMap id="StudentMap" type="com.crud.model.Student">
		<id property="sno" column="sno" javaType="java.lang.Integer"/>
		<result property="sname" column="sname" javaType="java.lang.String"/>
		<result property="score" column="score" javaType="java.lang.Double"/>
	</resultMap>
	
	<!-- id值与接口方法同名 -->
	<insert id="insertStudent">
		                <!-- 数据库字段名	实体类属性名(占位符) -->
		insert into student(sno,sname,score) values(#{sno},#{sname},#{score})
	</insert>
			<!-- parameterType参数类型设置 -->
	<update id="updateStudent" parameterType="com.crud.model.Student">
		update student set sname=#{sname},score=#{score} where sno=#{sno}
	</update>
			<!-- 参数类型设置 -->
	<delete id="deleteStudent" parameterType="int">
		delete from student where sno=#{sno}
	</delete>
			<!-- resultType结果集类型(没有设置别名时，使用完全限定名) -->
	<select id="selectStudent" resultType="com.crud.model.Student">
		select * from student where sno=#{sno}
	</select>
	
	<select id="selectAllStudent" resultMap="StudentMap">
		select * from student
	</select>

</mapper>

6、数据库操作工具类

package com.crud.tool;

import java.io.IOException;
import java.io.Reader;

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 DBtool {

	public static SqlSessionFactory sqlSessionFactory;
	
	static{
		try {
			Reader reader=Resources.getResourceAsReader("mybatis.cif.xml");
			sqlSessionFactory=new SqlSessionFactoryBuilder().build(reader);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	public static SqlSession getSqlSession(){
		return sqlSessionFactory.openSession();
	}
}

7、增删改查服务测试

package com.crud.service;

import java.util.List;

import com.crud.mapper.InterStudentMapper;
import com.crud.mapper.StudentMapperImpl;
import com.crud.model.Student;

public class StudentService{
	public static void main(String[] args) {
		
		InterStudentMapper stuMapper=new StudentMapperImpl();
		
		stuMapper.insertStudent(new Student(1002,"gan",100));
		
		stuMapper.deleteStudent(1100);
		
		stuMapper.updateStudent(new Student(1000,"master",88));
		
		Student stu=stuMapper.selectStudent(1001);
		System.out.println(stu);
		
		List<Student> list=stuMapper.selectAllStudent();
		System.out.println(list);
	}
	 
}

8、结果

前

后