步驟:
開發預備:
eclipse開發環境,下載mybaits.3.5.4.zip,mysql數據庫 數據庫world, 裏面有表user
字段:
user_name password,email
1.new Dynamic web project
2.將mybait3.5.4.zip解壓縮,找到lib文件夾,把裏面的東西copy到WEB-INF 的lib文件夾下。把mybaits.3.5.4.jar也拷貝進去
3.java SRC下面新建幾個包分別對應不同的功能。
cn.mybaits.util 封裝mybaits的配置
cn.mybais.dao 增刪改除的操作
cn.mybaits.entity 封裝實體類
cn.mybaits.test 測試用
總體目錄結構
4.在src下面創建Mybaits.config.xml
主要功能是指定連接數據庫的名稱,密碼,用戶名等
配置信息如下:
<?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>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC">
</transactionManager>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/world?serverTimezone=UTC"/> //world是數據庫名
<property name="username" value="root"/>
<property name="password" value="root"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="cn/mybaits/dao/user.mapper.xml"/> //usr.mapper.xml是用戶表user對應的映射信息。數據庫中有表user
</mappers>
</configuration>
user.mapper.xml的代碼如下:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" //注意裏面配置的是mapper不是config了
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.mybaits.dao.UserDao">
<select id = "selectUser" resultType="cn.mybaits.entity.User"> //id是方法名,resultType是返回類型
select * from user where user_name = #{name}
</select>
<insert id = "addWorld" parameterType="cn.mybaits.entity.User" useGeneratedKeys="true">
insert into user(name,password,email)values(#{name},#{password},#{email})
</insert>
<delete id = "deleteUser">
delete from user where id = #{id}
</delete>
</mapper>
創建實體類User對應數據庫表user:
package cn.mybaits.entity;
public class User {
private String name;
private String password;
private String email;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public User() {
super();
}
}
創建工具類Mybaitsutil:
package cn.mybaits.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 Mybaitsutil { //配置信息
public static SqlSessionFactory getSqlSessionFactory() throws IOException {
String resource = "Mybaits.config.xml";
InputStream inputstream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlsessionfactory = new SqlSessionFactoryBuilder().build(inputstream);
return sqlsessionfactory;
}
public static SqlSession getSqlSession() throws IOException {
SqlSessionFactory sessionFactory = getSqlSessionFactory();
SqlSession session = sessionFactory.openSession();
return session;
}
}
創建UserDao接口:
簡單實現兩個功能
package cn.mybaits.dao;
import cn.mybaits.entity.User;
public interface UserDao {
/**
* 通過id刪除用戶
* @param id
*/
void deleteUser(int id);
/**
* 根據id查詢一條結果集,返回一個實體對象
* @param uid
* @return
*/
User selectUser(String name);
}
構建類實現接口:
package cn.mybaits.dao;
import java.io.Console;
import java.io.IOException;
import org.apache.ibatis.session.SqlSession;
import cn.mybaits.entity.User;
import cn.mybaits.util.Mybaitsutil;
public class UserDaoImpl implements UserDao{
@Override
public void deleteUser(int id) {
// TODO Auto-generated method stub
try(SqlSession sqlSession = Mybaitsutil.getSqlSession()){
sqlSession.getMapper(UserDao.class).deleteUser(id);
}catch (RuntimeException e){
throw e;
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
@Override
public User selectUser(String name) {
// TODO Auto-generated method stub
try(SqlSession sqlSession = Mybaitsutil.getSqlSession()) {
User user = sqlSession.getMapper(UserDao.class).selectUser(name);
System.out.println(name);
return user;
}catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
return null;
}
}
}
測試運行用application。
package cn.mybaits.text;
import cn.mybaits.dao.UserDaoImpl;
import cn.mybaits.entity.User;
public class Main {
public static void main(String args[]) {
UserDaoImpl handle = new UserDaoImpl();
User u = handle.selectUser("tide");
System.out.println(u.getEmail());
}
}