Java EE框架

1、表现层 springMVC

2、粘合剂 spring（IOC/控制反转 AOP/面向切面编程 DI/依赖注入）

3、持久层 mybatis

Dao模式创建mybatis项目过程

1、下载jar包

mybatis jar包下载地址：

链接：https://pan.baidu.com/s/1xvZauxhkAPYxWvoJuxlLFg 

提取码：ia7w 

复制这段内容后打开百度网盘手机App，操作更方便哦

mybatis中文手册地址：

http://www.dba.cn/book/mybatis/MYBATISZhongWenShouCe/MYBATISXMLPeiZhi.html

2、导入所需要的jar包

commons-logging-1.2.jar 用于日志处理

log4j-1.2.17.jar 日志系统，负责日志输出

mybatis-3.5.0.jar mybatis核心jar包

mysql-connector-java-5.1.46.jar MySQL数据库驱动jar包

将jar包部署到项目中

3、编写mybatis核心配置文件

创建mybatis核心配置文件mybatis-config.xml

创建Java属性配置文件jdbc.properties

创建日志属性配置文件log4j.properties

mybatis-config.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD config.3.0//EN" 

"mybatis-3-config.dtd" >

<configuration>

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

 <typeAliases>

  <package name="com.Model"/>

 </typeAliases>

 <environments default="development">

  <environment id="development">

   <transactionManager type="JDBC">

   </transactionManager>

   <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>

  <package name="com.user"/>

 </mappers>

</configuration>

jdbc.properties

jdbc.DriverClassName=com.mysql.jdbc.Driver

jdbc.url=jdbc:mysql://localhost:3306/数据库名?characterEncoding=utf-8

jdbc.username=用户名

jdbc.password=密码

log4j.properties

log4j.rootLogger=DEBUG, Console

#Console

log4j.appender.Console=org.apache.log4j.ConsoleAppender

log4j.appender.Console.layout=org.apache.log4j.PatternLayout

log4j.appender.Console.layout.ConversionPattern=%d [%t] %-5p [%c] - %m%n

log4j.logger.java.sql.ResultSet=INFO

log4j.logger.org.apache=INFO

log4j.logger.java.sql.Connection=DEBUG

log4j.logger.java.sql.Statement=DEBUG

log4j.logger.java.sql.PreparedStatement=DEBUG

4、创建实体类

创建实体类并生成seter/geter方法重写toString方法。

User.java

package com.model;

public class User {

 private int userId;

 private String userName;

 private String userPass;

 private int userSex;

 private int userAge;

 public int getUserId() {

  return userId;

 }

 public void setUserId(int userId) {

  this.userId = userId;

 }

 public String getUserName() {

  return userName;

 }

 public void setUserName(String userName) {

  this.userName = userName;

 }

 public String getUserPass() {

  return userPass;

 }

 public void setUserPass(String userPass) {

  this.userPass = userPass;

 }

 public int getUserSex() {

  return userSex;

 }

 public void setUserSex(int userSex) {

  this.userSex = userSex;

 }

 public int getUserAge() {

  return userAge;

 }

 public void setUserAge(int userAge) {

  this.userAge = userAge;

 }

 @Override

 public String toString() {

  return "User [userId=" + userId + ", userName=" + userName + ", userPass=" + userPass + ", userSex=" + userSex

    + ", userAge=" + userAge + "]";

 }

}

5、创建Dao接口

UserDao.java

package com.dao;

import com.model.User; 

public interface UserDao {

 public User findUserById(int Id);

 //通过id查询用户信息

 public void addUser(User user);

 //向数据库中增加用户信息

 public void deleteUser(int Id);

//删除用户信息

public void updateUser(User user);

//修改用户信息

}

userService.java

package com.service;

import com.model.User;

public interface userService {

 public User findUserById(int Id);

 public void addUser(User user);

 public void deleteUser(int Id);

 

public void updateUser(User user);

}

6、创建 sql 映射文件

在dao包下创建sql映射文件 UserDao.xml。这里使用mapper动态代理所以映射文件必须和接口UserDao.java在同一个包下。

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD mapper.3.0//EN" "mybatis-3-mapper.dtd" >

<mapper namespace="com.mzdx.dao.UserDao">

     <select id="findUserById" parameterType="int" resultType="user">

  select * from userdb where userId=#{Id}

     </select>

     <insert id="addUser" parameterType="user">

  insert into userdb (userName,userPass,userSex,userAge)

  values (#{userName},#{userPass},#{userSex},#{userAge})

    </insert> 

    <delete id="deleteUser" parameterType="int">

  delete from userdb where userId=#{value}

    </delete> 

    <update id="updateUser" parameterType="user"> 

 update userdb set userName=#{userName},userPass=#{userPass},userSex=#{userSex},userAge=#{userAge} 

 where userId=#{userId}

 </update>

</mapper>

7、单例模式创建SqlSessionFactory工厂

MyBatisUtilsLazy.java

package com.utils;

import java.io.InputStream;

import org.apache.ibatis.io.Resources;

import org.apache.ibatis.session.SqlSessionFactory;

import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class MyBatisUtilsLazy {

 public static SqlSessionFactory factory=null;

 public static SqlSessionFactory getFactory() {

  if (factory==null) {

   InputStream in;

   try {

   synchronized(MyBatisUtilsLazy.class){

   if (factory==null) {

      in =Resources.getResourceAsStream("mybatis-config.xml");

      factory = new SqlSessionFactoryBuilder().build(in);

     } 

    }

   } catch (Exception e) {

      // TODO Auto-generated catch block

      e.printStackTrace();

   }

  }

  return factory;

 }

}

8、编写实现类

UserServiceImpl.java

package com.service.impl;

import org.apache.ibatis.session.SqlSession;

import com.dao.UserDao;

import com.model.User;

import com.service.userService;

import com.utils.MyBatisUtilsLazy;

public class UserServiceImpl implements userService {

     SqlSession session = MyBatisUtilsLazy.getFactory().openSession();

 UserDao mapper = session.getMapper(UserDao.class);

 @Override

 public User findUserById(int Id) {

  // TODO Auto-generated method stub

  return mapper.findUserById(Id);

 }

 @Override

 public void addUser(User user) {

  // TODO Auto-generated method stub

  try {

   mapper.addUser(user);

   session.commit();

  } catch (Exception e) {

   // TODO Auto-generated catch block

   e.printStackTrace();

  }finally {

   session.close();

  }

 }

 @Override

 public void deleteUser(int Id) {

  // TODO Auto-generated method stub

  try {

   mapper.deleteUser(Id);

   session.commit();

  } catch (Exception e) {

   // TODO Auto-generated catch block

   e.printStackTrace();

  }finally {

   session.close();

  }

 }

 @Override

 public void updateUser(User user) {

  // TODO Auto-generated method stub

  try {

   mapper.updateUser(user);

   session.commit();

  } catch (Exception e) {

   // TODO Auto-generated catch block

   e.printStackTrace();

  }finally {

   session.close();

  }

 }

}

9、编写测试类

TestAddUser.java

package com.test;

import org.junit.Test;

import com.model.User;

import com.service.impl.UserServiceImpl;

public class TestAddUser {

 @Test

 public void testAddUser() {

  UserServiceImpl userServiceImpl = new UserServiceImpl();

  User user = new User();

  String userName="aaa";

  String userPass="152425";

  int userSex=0;

  int userAge=28;

  user.setUserName(userName);

  user.setUserPass(userPass);

  user.setUserSex(userSex);

  user.setUserAge(userAge);

  userServiceImpl.addUser(user);

  System.out.println(user);

 }

}

TestDeleteUser.java

package com.test;

import org.junit.Test;

import com.service.impl.UserServiceImpl;

public class TestDeleteUser {

 @Test

 public void testdeleteUser() {

  UserServiceImpl userServiceImpl = new UserServiceImpl();

  int Id=16;

  userServiceImpl.deleteUser(Id);

 }

}

TestFindUserById.java

package com.test;

import org.junit.jupiter.api.Test;

import com.model.User;

import com.service.impl.UserServiceImpl;

public class TestFindUserById {

 @Test

 public void testFindUserById(){

  UserServiceImpl userServiceImpl = new UserServiceImpl();

  int Id=17;

  User user = userServiceImpl.findUserById(Id);

  System.out.println(user);

 }

}

TestUpdateUser.java

package com.test;

import org.junit.Test;

import com.model.User;

import com.service.impl.UserServiceImpl;

public class TestUpdateUser {

 @Test

 public void testupdateUser() {

  UserServiceImpl userServiceImpl = new UserServiceImpl();

  User user = new User();

  String userName="张三";

  String userPass="152425";

  int userSex=0;

  int userAge=25;

  user.setUserId(18);

  user.setUserName(userName);

  user.setUserPass(userPass);

  user.setUserSex(userSex);

  user.setUserAge(userAge);

  userServiceImpl.updateUser(user);

  System.out.println(user);

 }

}