MyBatis项目学习笔记

柔光的暖阳◎ 2022-05-23 05:09 221阅读 0赞

MyBatis 是一款优秀的[持久层][Link 1]框架，它支持定制化 SQL、存储过程以及高级映射。MyBatis 避免了几乎所有的 JDBC 代码和手动设置参数以及获取[结果集][Link 2]。MyBatis 可以使用简单的 XML 或注解来配置和映射原生信息，将接口和 Java 的 POJOs(Plain Old Java Objects,普通的 Java对象)映射成数据库中的记录。

@Controller  控制层，就是我们的action层

@Service   业务逻辑层，就是我们的service或者manager层

@Repository  持久层，就是我们常说的DAO层

而@Component （字面意思就是组件），它在你确定不了事哪一个层的时候使用。

其实，这四个注解的效果都是一样的，Spring都会把它们当做需要注入的Bean加载在上下文中；

但是在项目中，却建议你严格按照除Componen的其余三个注解的含义使用在项目中。这对分层结构的web架构很有好处！！

![70][]

项目所需Jar包：

![70 1][]

连接数据库SQL语句：

CREATE DATABASE manpower;

USE manpower;

CREATE TABLE \`user\` (

\`id\` INT(10) NOT NULL AUTO\_INCREMENT,

\`name\` VARCHAR(20) DEFAULT NULL,

\`sex\` VARCHAR(10) DEFAULT NULL,

\`birthday\` DATE DEFAULT NULL,

\`feature\` VARCHAR(10) DEFAULT NULL,

\`job\` VARCHAR(10) DEFAULT NULL,

\`jobname\` VARCHAR(15) DEFAULT NULL,

\`education\` VARCHAR(20) DEFAULT NULL,

PRIMARY KEY (\`id\`)

) ENGINE=INNODB AUTO\_INCREMENT=2 DEFAULT CHARSET=utf8

INSERT INTO USER(id,NAME,sex,birthday,feature,job,jobname,education)

VALUES(1,"张三","男","1996-8-8","党员","IT","程序员","本科")

INSERT INTO USER(id,NAME,sex,birthday,feature,job,jobname,education)

VALUES(3,"李四","女","1992-8-8","党员","教育","老师","本科")

jdbc.properties数据库文件配置 ：

driver=com.mysql.jdbc.Driver

url = jdbc\\:mysql\\://localhost\\:3306/manpower

username = root

password = 1234

log4j.properties日志文件配置:

\# Global logging configuration

log4j.rootLogger=DEBUG, stdout

\# Console output...

log4j.appender.stdout=org.apache.log4j.ConsoleAppender

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

log4j.appender.stdout.layout.ConversionPattern=%5p \[%t\] \- %m%n

实体类：

**package** cn.wallance.domain;

**public** **class** User \{

**private** **int** id;

**private** String name;

**private** String sex;

**private** String birthday;

**private** String feature;

**private** String job;

**private** String jobname;

**private**  String education;

**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** String getSex()

**return** sex;

**public** **void** setSex(String sex)

**this**.sex = sex;

**public** String getBirthday()

**return** birthday;

**public** **void** setBirthday(String birthday)

**this**.birthday = birthday;

**public** String getFeature()

**return** feature;

**public** **void** setFeature(String feature)

**this**.feature = feature;

**public** String getJob()

**return** job;

**public** **void** setJob(String job)

**this**.job = job;

**public** String getJobname()

**return** jobname;

**public** **void** setJobname(String jobname)

**this**.jobname = jobname;

**public** String getEducation()

**return** education;

**public** **void** setEducation(String education)

**this**.education = education;

Dao接口:

package cn.wallance.dao;

import java.util.List;

import cn.wallance.domain.User;

public interface IUserDao \{

//全查询

public abstract List<User> selectAll();

//插入数据

public abstract int addUser(User user);

//删除数据

public abstract int deleteUser(int id);

//查询一个用户

public abstract User selectone(int id);

//修改数据

public abstract int updateUser(User user);

Dao接口实现类：

package cn.wallance.dao;

import java.util.List;

import javax.annotation.Resource;

Import

org.apache.ibatis.session.SqlSessionFactory;

import org.mybatis.spring.support.SqlSessionDaoSupport;

import org.springframework.stereotype.Repository;

import cn.wallance.domain.User;

@Repository("userDao")//注解是告诉Spring，让Spring创建一个名字叫“userDao”的UserDaoImpl实例。

public class UserDaoImpl extends SqlSessionDaoSupport implements IUserDao \{

@Resource

public void setSuperSessionFactory(SqlSessionFactory sessionFactory)\{

this.setSqlSessionFactory(sessionFactory);

public List<User> selectAll() \{

// TODO Auto-generated method stub

List<User> users = this.getSqlSession().selectList("getUser");

return users;

@Override

public int addUser(User user) \{

// TODO Auto-generated method stub

int add=this.getSqlSession().insert("adduser",user);

return add;

@Override

public int deleteUser(int id)

// TODO Auto-generated method stub

int del=this.getSqlSession().delete("delete",id);

return del;

@Override

public User selectone(int id)

// TODO Auto-generated method stub

User sl=this.getSqlSession().selectOne("selectone",id);

return sl;

@Override

public int updateUser(User user)

// TODO Auto-generated method stub

int up=this.getSqlSession().update("update",user);

return up;

Mapper映射文件：

<?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=*"cn.wallance.mapping.classMapper"*>

<select id=*"getUser"* resultType=*"cn.wallance.domain.User"*>

select \* from user

</select>

<insert id=*"adduser"* parameterType=*"cn.wallance.domain.User"*>

insert into user(name,sex,birthday,feature,job,jobname,education)

values(\#\{name\},\#\{sex\},\#\{birthday\},\#\{feature\},\#\{job\},\#\{ jobname\},\#\{education\})

</insert>

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

delete from user where id=\#\{id\}

</delete>

<select id=*"selectone"* parameterType=*"int"* resultType=*"cn.wallance.domain.User"*>

select \* from user where id=\#\{id\}

</select>

<update id=*"update"* parameterType=*"cn.wallance.domain.User"*>

update user set name=\#\{name\},sex=\#\{sex\},birthday=\#\{birthday\},

feature=\#\{feature\},job=\#\{job\},jobname=\#\{ jobname\},education=\#\{education\}

where id=\#\{id\}

</update>

</mapper>

业务逻辑层service接口：

package cn.wallance.service;

import java.util.List;

import cn.wallance.domain.User;

public interface IUserService \{

public abstract List<User> selectAll();

public abstract  int addUser(User user);

public abstract int deleteUser(int id);

public abstract User selectone(int id);

public abstract int updateUser(User user);

业务逻辑层service接口实现类：

package cn.wallance.service;

import java.util.List;

import javax.annotation.Resource;

import org.springframework.stereotype.Service;

import cn.wallance.dao.IUserDao;

import cn.wallance.domain.User;

@Service("userService")

public class UserServiceImpl implements IUserService \{

private IUserDao userDao;

public IUserDao getUserDao() \{

return userDao;

@Resource

public void setUserDao(IUserDao userDao) \{

this.userDao = userDao;

@Override

public List<User> selectAll() \{

// TODO Auto-generated method stub

return userDao.selectAll();

@Override

public int  addUser(User user) \{

// TODO Auto-generated method stub

return userDao.addUser(user);

@Override

public int deleteUser(int id)

// TODO Auto-generated method stub

return userDao.deleteUser(id);

@Override

public User selectone(int id)

// TODO Auto-generated method stub

return userDao.selectone(id);

@Override

public int updateUser(User user)

// TODO Auto-generated method stub

return userDao.updateUser(user);

Controller层（用于服务客户端请求的服务端）：

package cn.wallance.web;

import java.util.Date;

import java.util.List;

import javax.annotation.Resource;

import javax.swing.Spring;

import org.springframework.stereotype.Controller;

import org.springframework.ui.Model;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import org.springframework.web.bind.annotation.RequestParam;

import cn.wallance.domain.User;

import cn.wallance.service.IUserService;

@Controller

public class HomeController \{

private IUserService userService;

public IUserService getUserService() \{

return userService;

@Resource

public void setUserService(IUserService userService) \{

this.userService = userService;

@RequestMapping(value="/home",method=RequestMethod.GET)

public String home(Model model)\{

List<User> users = userService.selectAll();

model.addAttribute("users", users);

return "home";

@RequestMapping(value="/insert",method=RequestMethod.GET)

public String insert(Model model)\{

return "insert";

@RequestMapping(value="/insert",method=RequestMethod.POST)

public String insert(String name, String sex, String birthday,

String feature, String job,String jobname,String education)\{

User user=new User();

user.setName(name);

user.setSex(sex);

user.setBirthday(birthday);

user.setFeature(feature);

user.setJob(job);

user.setJobname(jobname);

user.setEducation(education);

userService.addUser(user);

return "redirect:home";

@RequestMapping(value="/delete",method=RequestMethod.GET)

public String delete(Model model,int id)\{

userService.deleteUser(id);

return "redirect:home";

@RequestMapping(value="/update",method=RequestMethod.GET)

public String update(Model model,int id)\{

User user=userService.selectone(id);

model.addAttribute("user",user);

return "update";

@RequestMapping(value="/update",method=RequestMethod.POST)

public String update(int id,User user)\{

userService.updateUser(user);

return "redirect:home";

**school-mybatis.xml环境配置文件：**

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

<beans xmlns=*"http://www.springframework.org/schema/beans"* xmlns:xsi=*"http://www.w3.org/2001/XMLSchema-instance"*

xmlns:mybatis=*"http://mybatis.org/schema/mybatis-spring"*

xmlns:context=*"http://www.springframework.org/schema/context"*

xsi:schemaLocation=*"http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd  *

*       http://mybatis.org/schema/mybatis-spring http://mybatis.org/schema/mybatis-spring.xsd  *

*       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"*>

<context:component-scan base-package=*"cn.wallance"* />

<bean id=*"propertyConfigurer"*

class=*"org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"*>

<property name=*"location"* value=*"classpath:jdbc.properties"* />

</bean>

<bean id=*"dataSource"* class=*"org.apache.commons.dbcp.BasicDataSource"*

destroy-method=*"close"*>

<property name=*"driverClassName"* value=*"$\{driver\}"* />

<property name=*"url"* value=*"$\{url\}"* />

<property name=*"username"* value=*"$\{username\}"* />

<property name=*"password"* value=*"$\{password\}"* />

<property name=*"initialSize"* value=*"1"* />

<property name=*"minIdle"* value=*"1"* />

<property name=*"maxActive"* value=*"100"* />

<property name=*"maxIdle"* value=*"20"* />

<property name=*"maxWait"* value=*"1000"* />

</bean>

<bean id=*"sqlSessionFactory"* class=*"org.mybatis.spring.SqlSessionFactoryBean"*>

<property name=*"dataSource"* ref=*"dataSource"* />

<property name=*"mapperLocations"* value=*"classpath:cn/wallance/mapping/\*.xml"*></property>

</bean>

<bean class=*"org.mybatis.spring.mapper.MapperScannerConfigurer"*>

<property name=*"basePackage"* value=*"cn.wallance.dao"* />

<property name=*"sqlSessionFactoryBeanName"* value=*"sqlSessionFactory"*></property>

</bean>

<bean id=*"transactionManager"*

class=*"org.springframework.jdbc.datasource.DataSourceTransactionManager"*>

<property name=*"dataSource"* ref=*"dataSource"* />

</bean>

</beans>

**school-servlet.xml注解配置文件：**

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

<beans xmlns=*"http://www.springframework.org/schema/beans"*

xmlns:xsi=*"http://www.w3.org/2001/XMLSchema-instance"*

xmlns:context=*"http://www.springframework.org/schema/context"*

xmlns:mvc=*"http://www.springframework.org/schema/mvc"*

xsi:schemaLocation=*"http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd*

*http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd*

*http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd"*>

<mvc:annotation-driven/>

<context:component-scan base-package=*"cn.wallance.web"*/>

<bean class = *"org.springframework.web.servlet.view.InternalResourceViewResolver"*>

<property name=*"prefix"* value=*"/WEB-INF/school/"* />

<property name=*"suffix"* value=*".jsp"* />

</bean>

</beans>

web.xml配置文件:

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

<web-app xmlns:xsi=*"http://www.w3.org/2001/XMLSchema-instance"* xmlns=*"http://java.sun.com/xml/ns/javaee"* xsi:schemaLocation=*"http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app\_3\_0.xsd"* id=*"WebApp\_ID"* version=*"3.0"*>

<servlet-name>school</servlet-name>

<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>school</servlet-name>

<url-pattern>/</url-pattern>

</servlet-mapping>

<context-param>

<param-name>contextConfigLocation</param-name>

<param-value>classpath:school-mybatis.xml</param-value>

</context-param>

<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>

</listener>

<filter-name>CharacterFilter</filter-name>

<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>

<init-param>

<param-name>encoding</param-name>

<param-value>UTF-8</param-value>

</init-param>

</filter>

<filter-mapping>

<filter-name>CharacterFilter</filter-name>

<url-pattern>/\*</url-pattern>

</filter-mapping>

</web-app>

**JSp页面(home.jsp)：**

** ![70 2][]**

<%@ page language=*"java"* import=*"java.util.\*"* pageEncoding=*"UTF-8"*%>

<%@ taglib prefix=*"c"* uri=*"http://java.sun.com/jsp/jstl/core"* %>

String path = request.getContextPath();

String basePath = request.getScheme()+"://"\+request.getServerName()+":"\+request.getServerPort()+path+"/";

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<base href=*"*<%=basePath%>*"*>

<title>My JSP 'index.jsp' starting page</title>

<!--

\-->

</head>

<body>

<table border=*"6"*>

<caption>人员信息表</caption>

<tr>

</tr>

<c:forEach items="$\{users\}" var=*"user"*>

<tr>

<td>$\{user.birthday\}</td>

<td>$\{user.feature\}</td>

<td>$\{user.jobname\}</td>

<td>$\{user.education\}</td>

</tr>

</c:forEach>

</table>

<a href=*"insert"*>新增人员</a>

</body>

</html>

** **

Insert.jsp(添加页面):

![70 3][]

<%@ page language=*"java"* import=*"java.util.\*"* pageEncoding=*"UTF-8"*%>

<%@ taglib prefix=*"c"* uri=*"http://java.sun.com/jsp/jstl/core"* %>

String path = request.getContextPath();

String basePath = request.getScheme()+"://"\+request.getServerName()+":"\+request.getServerPort()+path+"/";

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<base href=*"*<%=basePath%>*"*>

<title>My JSP 'index.jsp' starting page</title>

<!--

\-->

</head>

<body>

<table border=*"6"*>

<caption>人员信息表</caption>

<tr>

</tr>

<c:forEach items="$\{users\}" var=*"user"*>

<tr>

<td>$\{user.birthday\}</td>

<td>$\{user.feature\}</td>

<td>$\{user.jobname\}</td>

<td>$\{user.education\}</td>

</tr>

</c:forEach>

</table>

<a href=*"insert"*>新增人员</a>

</body>

</html>

update.jsp（修改页面）：

<%@ page language=*"java"* contentType=*"text/html; charset=utf-8"*

pageEncoding=*"utf-8"*%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Insert title here</title>

</head>

<body>

<table border=*"6"*>

<caption>人员信息表</caption>

<tr>

</tr>

<tr>

</tr>

<tr>

<form action=*"update"* method=*"post"*>

</form>

</tr>

</table>

</body>

</html>

[Link 1]: https://baike.sogou.com/v55187093.htm
[Link 2]: https://baike.sogou.com/v66020459.htm
[70]: /images/20220523/371df3e9965f46598957469adecf1ac0.png
[70 1]: /images/20220523/53e17f15258242818edfc3b1b1406a15.png
[70 2]: /images/20220523/23c2f794a9524c00a2312bdac80bdaf4.png
[70 3]: /images/20220523/9a9592fe192b4afa8f02248b9e51f212.png