pom.xml:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.xf</groupId>
<artifactId>Mymybatis</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.5</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.25</version>
</dependency>
</dependencies>
<build>
<!--解决xml没有到target-->
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
</build>
</project>
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>
<typeAlias type="com.xf.mybatis.pojo.User" alias="user"/>
</typeAliases>
<!-- 配置MyBatis运行环境 -->
<environments default="development">
<environment id="development">
<!-- 配置JDBC事务管理 -->
<transactionManager type="JDBC"></transactionManager>
<!-- POOLED配置JDBC数据源连接池 -->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://120.78.195.41:3306/test?useUnicode=true&characterEncoding=UTF-8"/>
<property name="username" value="***"/>
<property name="password" value="***"/>
</dataSource>
</environment>
</environments>
<!--注册UserMapper.xml-->
<mappers>
<!--动态sql-->
<mapper resource="com/xf/mybatis/mapper/UserMapperSql.xml"/>
</mappers>
</configuration>
User:
package com.xf.mybatis.pojo;
public class User {
private int id;
private String username;
private String password;
private int age;
public User() {
}
public User(int id, String username, String password, int age) {
this.id = id;
this.username = username;
this.password = password;
this.age = age;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", password='" + password + '\'' +
", age=" + age +
'}';
}
}
UserMapper.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.xf.mybatis.pojo.User">
<resultMap type="user" id="userMap">
<id property="id" column="id"/>
<result property="username" column="username"/>
<result property="password" column="password"/>
<result property="age" column="age"/>
</resultMap>
<select id="findAll" parameterType="map" resultMap="userMap">
select * from t_user
<where>
<if test="pid!=null">
and id = #{pid}
</if>
<if test="pname!=null">
and username = #{pname}
</if>
</where>
</select>
<!--set标签自动判断哪个是最后一个字段,会自动去掉最后一个,号 -->
<update id="updateUser" parameterType="map">
UPDATE t_user
<set>
<if test="username!=null">
username=#{username},
</if>
<if test="password!=null">
password=#{password},
</if>
</set>
WHERE id=#{id}
</update>
<!--
foreach用于迭代数组元素
open表示开始符号
close表示结束符号
separator表示元素间的分隔符
item表示迭代的数组
collection类型,二选其一,所以parameterType="array"就不要了
#{ids}表示数组中的每个元素值
-->
<delete id="deleteUser">
DELETE from t_user where id IN
<foreach collection="array" open="(" close=")" separator="," item="ids">
#{ids}
</foreach>
</delete>
<delete id="deleteUserList">
DELETE from t_user where id IN
<foreach collection="list" open="(" close=")" separator="," item="ids">
#{ids}
</foreach>
</delete>
<!--sql片段对应的字段名-->
<sql id="key">
/*去掉最后一个,*/
<trim suffixOverrides=",">
<if test="id!=null">
id,
</if>
<if test="username!=null">
username,
</if>
<if test="password!=null">
password,
</if>
</trim>
</sql>
<!--sql片段对应? id属性值任意-->
<sql id="value">
/*去掉最后一个,*/
<trim suffixOverrides=",">
<if test="id!=null">
#{id},
</if>
<if test="username!=null">
#{username},
</if>
<if test="password!=null">
#{ password},
</if>
</trim>
</sql>
<insert id="insertUser" parameterType="user">
insert into t_user(<include refid="key"/>) VALUE (<include refid="value"/>)
</insert>
</mapper>
MybatisUtils:
package com.xf.mybatis.utils;
import java.io.IOException;
import java.io.Reader;
import java.sql.Connection;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
/*
* 工具类
* @author XF
*/
public class MybatisUtil {
private static ThreadLocal<SqlSession> threadLocal = new ThreadLocal<SqlSession>();
private static SqlSessionFactory sqlSessionFactory;
// 加载位于src/mybatis.xml配置文件
static{
try {
Reader reader = Resources.getResourceAsReader("config.xml");
sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
} catch (IOException e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
// 禁止外界通过new方法创建
private MybatisUtil(){}
// 获取SqlSession
public static SqlSession getSqlSession(){
//从当前线程中获取SqlSession对象
SqlSession sqlSession = threadLocal.get();
//如果SqlSession对象为空
if(sqlSession == null){
//在SqlSessionFactory非空的情况下,获取SqlSession对象
sqlSession = sqlSessionFactory.openSession();
//将SqlSession对象与当前线程绑定在一起
threadLocal.set(sqlSession);
}
//返回SqlSession对象
return sqlSession;
}
// 关闭SqlSession与当前线程分开
public static void closeSqlSession(){
//从当前线程中获取SqlSession对象
SqlSession sqlSession = threadLocal.get();
//如果SqlSession对象非空
if(sqlSession != null){
//关闭SqlSession对象
sqlSession.close();
//分开当前线程与SqlSession对象的关系,目的是让GC尽早回收
threadLocal.remove();
}
}
// 测试
public static void main(String[] args) {
Connection conn = MybatisUtil.getSqlSession().getConnection();
System.out.println(conn!=null?"连接成功":"连接失败");
}
}
UserDao:
package com.xf.mybatis.Dao;
import com.xf.mybatis.pojo.User;
import com.xf.mybatis.utils.MybatisUtil;
import org.apache.ibatis.session.SqlSession;
import java.util.*;
public class UserDaoSql {
/**
* 有条件的查询所有
*/
public List<User> findAll(int id, String name) throws Exception {
SqlSession sqlSession = null;
try {
sqlSession = MybatisUtil.getSqlSession();
Map<String, Object> map = new LinkedHashMap<String, Object>();
map.put("pid", id);
map.put("pname", name);
return sqlSession.selectList(User.class.getName() + ".findAll", map);
} catch (Exception e) {
e.printStackTrace();
throw e;
} finally {
MybatisUtil.closeSqlSession();
}
}
/**
* 有条件的跟新
*
* @param id
* @param username
* @param password
*/
public void updateUser(Integer id, String username, String password) {
SqlSession sqlSession = null;
try {
sqlSession = MybatisUtil.getSqlSession();
Map<String, Object> map = new HashMap<String, Object>();
map.put("id", id);
map.put("username", username);
map.put("password", password);
sqlSession.update(User.class.getName() + ".updateUser", map);
sqlSession.commit();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 按数组动态删除
*
* @param ids
*/
public void deleteUser(int... ids) {
SqlSession sqlSession = null;
try {
sqlSession = MybatisUtil.getSqlSession();
sqlSession.delete(User.class.getName() + ".deleteUser", ids);
sqlSession.commit();
} catch (Exception e) {
e.printStackTrace();
sqlSession.rollback();
throw e;
} finally {
MybatisUtil.closeSqlSession();
}
}
/**
* 按list动态删除
*
* @param ids
*/
public void deleteUserList(List<Integer> ids) {
SqlSession sqlSession = null;
try {
sqlSession = MybatisUtil.getSqlSession();
sqlSession.delete(User.class.getName() + ".deleteUserList", ids);
sqlSession.commit();
} catch (Exception e) {
e.printStackTrace();
sqlSession.rollback();
throw e;
} finally {
MybatisUtil.closeSqlSession();
}
}
/**
* 插入学生
*/
public void insertUser(User user) throws Exception{
SqlSession sqlSession = null;
try{
sqlSession = MybatisUtil.getSqlSession();
sqlSession.insert(User.class.getName()+".insertUser",user);
sqlSession.commit();
}catch(Exception e){
e.printStackTrace();
sqlSession.rollback();
throw e;
}finally{
MybatisUtil.closeSqlSession();
}
}
public static void main(String[] args) throws Exception {
UserDaoSql dao = new UserDaoSql();
//条件查找所有
/* List<User> list = dao.findAll(1,null);
for (User s : list) {
System.out.println(s.getId() + ":" + s.getUsername());
}*/
//修改
//dao.updateUser(1,null,"123456");
//数组删除
//dao.deleteUser(1,3,5,7);
// dao.deleteUser(new int[]{1,3,5,7});
//list删除
/* List<Integer> ids = new ArrayList<Integer>();
ids.add(4);
ids.add(6);
ids.add(8);
dao.deleteUserList(ids);*/
//dao.insertUser(new User(1,"哈哈","123"));//insert into 表名(*,*,*) values(?,?,?)
// dao.insertUser(new User(2,"哈哈",null));//insert into 表名(*,*) values(?,?)
//dao.insertUser(new User(3,null,"123456"));//insert into 表名(*,*) values(?,?)
dao.insertUser(new User(4,null,null));//insert into 表名(*) values(?)
}
}