IDEA完成Spring+Mybatis的增删改查

第一次写CSDN献给IDEA编译器里使用Maven搭建Spring4+Mybatis3的小教程。

以下内容参考“博客园”的一篇博客，传送门：Mybatis学习总结(八)。

需要用到的工具：IDEA | Tomcat | 连接mysql的Jar包 | mysql

一. 创建项目

1. IDEA版本2018.1

2.选择Maven类型，选择SDK1.8，Next

3.取个名字吧，Next

4.取个项目名字吧(建议以上的命名都一致)，设置项目路径，Next

5.留意右下角，选择Enable Auto-import

二. 正式开始

1. 修改pom.xml文件, 添加依赖

* 自行修改 | 标签为自己的项目名(projectName)

    4.0.0

    SpringMybatisDemo
    SpringMybatisDemo
    war
    http://maven.apache.org
    1.0-SNAPSHOT

    
        
        
            org.springframework
            spring-core
            4.1.4.RELEASE
        
        
        
            org.springframework
            spring-context
            4.1.4.RELEASE
        
        
        
            org.springframework
            spring-tx
            4.1.4.RELEASE
        
        
        
            org.springframework
            spring-jdbc
            4.1.4.RELEASE
        
        
        
            org.springframework
            spring-test
            4.1.4.RELEASE
        
        
        
            org.springframework
            spring-web
            4.1.4.RELEASE
        
        
        
            org.aspectj
            aspectjweaver
            1.8.5
        
        
        
            org.mybatis
            mybatis
            3.2.8
        
        
        
            org.mybatis
            mybatis-spring
            1.2.2
        
        
        
            javax.servlet
            javax.servlet-api
            3.0.1
        
        
            javax.servlet.jsp
            javax.servlet.jsp-api
            2.3.2-b01
        
        
        
            javax.servlet
            jstl
            1.2
        
        
        
            mysql
            mysql-connector-java
            5.1.34
        
        
        
            com.alibaba
            druid
            1.0.12
        
        
        
            junit
            junit
            4.12
            test
        
        
            junit
            junit
            4.12
            test
        
        
            junit
            junit
            4.12
            test
        
    

    
        spring4mybatis3
        
            
                src/main/java
                
                    **/*.xml
                
            
            
                src/main/resources
            
        
        
            
                org.mybatis.generator
                mybatis-generator-maven-plugin
                1.3.2
                
                    spring-mybatis.xml
                    true
                    true
                
                
                    
                        Generate MyBatis Artifacts
                        
                            generate
                        
                    
                
                
                    
                        org.mybatis.generator
                        mybatis-generator-core
                        1.3.2
                    
                
            
        
    

2. 添加数据库和数据表，以下使用Mysql

Create DATABASE spring4_mybatis3;
USE spring4_mybatis3;

DROP TABLE IF EXISTS t_user;
CREATE TABLE t_user (
  user_id char(32) NOT NULL,
  user_name varchar(30) DEFAULT NULL,
  user_birthday date DEFAULT NULL,
  user_salary double DEFAULT NULL,
  PRIMARY KEY (user_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

创建好的数据库和数据表如下

3. 在resources中添加四个配置文件dbconfig.properties | generatorConfig.xml | spring.xml | spring-mybatis.xml

dbconfig.properties(修改username | password)

driverClassName=com.mysql.jdbc.Driver
validationQuery=SELECT 1
jdbc_url=jdbc:mysql://localhost:3306/spring4_mybatis3?useUnicode=true&characterEncoding=UTF-8
jdbc_username=root
jdbc_password=123456

generatorConfig.xml

*修改mysql.connector-java.jar的路径

*修改数据库连接信息中userId | password

spring.xml

spring-mybatis.xml

    
    
    
    
    
        
        
        
        
        
        
        
        
        
        
        
        
        
        
        
        
        
        
    

    
        
        
    

    
        
        
    

    
        
    

    
        
            
            
            
            
            
            
            
            
            
            
            

            
            
            
            
            

            
        
    
    
        
        
    

    
    
    
        
            
                service.*
            
        
    
    
        
    

* 注意：各配置文件中有些地方会显示报错，都是因为没有依赖或者路径不正确或者文件不存在引起的。

4. 添加项目目录（dao | entity | mapping）

5. 在编译器的右边，有一个"Maven Projects"标签，打开选中Plugins，找到mybatis-generator,双击运行

若成功，控制台显示：

* 报错的话，请留意mysql连接的jar包版本问题 或 文件路径问题 或 文件名字问题

6. 以上，完成用generator插件自动生成代码。若生成失败，可以手写代码，如下展示：

entity/TUser.java

package entity;

import java.util.Date;

public class TUser {
    private String userId;

    private String userName;

    private Date userBirthday;

    private Double userSalary;

    public String getUserId() {
        return userId;
    }

    public void setUserId(String userId) {
        this.userId = userId == null ? null : userId.trim();
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName == null ? null : userName.trim();
    }

    public Date getUserBirthday() {
        return userBirthday;
    }

    public void setUserBirthday(Date userBirthday) {
        this.userBirthday = userBirthday;
    }

    public Double getUserSalary() {
        return userSalary;
    }

    public void setUserSalary(Double userSalary) {
        this.userSalary = userSalary;
    }
}

dao/TUserMapper

package dao;

import entity.TUser;
import entity.TUserExample;
import org.apache.ibatis.annotations.Param;

import java.util.List;

public interface TUserMapper {
    int countByExample(TUserExample example);

    int deleteByExample(TUserExample example);

    int deleteByPrimaryKey(String userId);

    int insert(TUser record);

    int insertSelective(TUser record);

    List selectByExample(TUserExample example);

    TUser selectByPrimaryKey(String userId);

    int updateByExampleSelective(@Param("record") TUser record, @Param("example") TUserExample example);

    int updateByExample(@Param("record") TUser record, @Param("example") TUserExample example);

    int updateByPrimaryKeySelective(TUser record);

    int updateByPrimaryKey(TUser record);

    List getAllUser();
}

mapping/TUserMapper.xml（删除了部分未用到的操作）

  
    
    
    
    
  
  
    user_id, user_name, user_birthday, user_salary
  
  
    select
    
    from t_user
    where user_id = #{userId,jdbcType=CHAR}
  
  
    delete from t_user
    where user_id = #{userId,jdbcType=CHAR}
  
  
    insert into t_user (user_id, user_name, user_birthday,
      user_salary)
    values (#{userId,jdbcType=CHAR}, #{userName,jdbcType=VARCHAR}, #{userBirthday,jdbcType=DATE},
      #{userSalary,jdbcType=DOUBLE})
  
  
    insert into t_user
    
      
        user_id,
      
      
        user_name,
      
      
        user_birthday,
      
      
        user_salary,
      
    
    
      
        #{userId,jdbcType=CHAR},
      
      
        #{userName,jdbcType=VARCHAR},
      
      
        #{userBirthday,jdbcType=DATE},
      
      
        #{userSalary,jdbcType=DOUBLE},
      
    
  
  
    update t_user
    
      
        user_name = #{userName,jdbcType=VARCHAR},
      
      
        user_birthday = #{userBirthday,jdbcType=DATE},
      
      
        user_salary = #{userSalary,jdbcType=DOUBLE},
      
    
    where user_id = #{userId,jdbcType=CHAR}
  
  
    update t_user
    set user_name = #{userName,jdbcType=VARCHAR},
      user_birthday = #{userBirthday,jdbcType=DATE},
      user_salary = #{userSalary,jdbcType=DOUBLE}
    where user_id = #{userId,jdbcType=CHAR}
  
  
        select user_id, user_name, user_birthday, user_salary from t_user
    

*使用插件后，立刻从pox.xml中删除标签内容，以免引起后面项目部署的时候重复自动生成代码。

三. 现在基本搭建完成，可以做一下单元测试

1. 建立service目录，如下

service / UserServiceI

package service;

import entity.TUser;

import java.util.List;

public interface UserServiceI {

    /**
     * 添加用户
     * @param user
    */
    void addUser(TUser user);

    /**
     * 根据用户id获取用户
     * @param userId
     * @return
     */
    TUser getUserById(String userId);

    /**获取所有用户信息
     * @return List
     */
    List getAllUser();

    /**删除指定用户
     * @param userId
     */
    void deleteByPrimaryKey(String userId);

    /**更新指定用户
     * @param user
     */
    void updateByPrimaryKey(TUser user);
}

service/impl/UserServiceImpl

package service.impl;

import dao.TUserMapper;
import entity.TUser;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import service.UserServiceI;

import java.util.List;

/**
 * 使用@Service注解将UserServiceImpl类标注为一个service
 * service的id是userService
 */
@Service("userService")
public class UserServiceImpl implements UserServiceI {

    /**
     * 使用@Autowired注解标注userMapper变量，
     * 当需要使用UserMapper时，Spring就会自动注入UserMapper
     */
    @Autowired
    private TUserMapper userMapper;//注入dao

    @Override
    public void addUser(TUser user) {
        userMapper.insert(user);
    }

    @Override
    public TUser getUserById(String userId) {
        return userMapper.selectByPrimaryKey(userId);
    }

    @Override
    public List getAllUser() {
        return userMapper.getAllUser();
    }

    @Override
    public void deleteByPrimaryKey(String userId) {
        userMapper.deleteByPrimaryKey(userId);
    }

    @Override
    public void updateByPrimaryKey(TUser user) {
        userMapper.updateByPrimaryKey(user);
    }
}

此时，可能会有报错：@Overide is not allowed when implementing interface method.

解决方法：右键project->Open Modules Setting->Language level->6-@Overide in interfaces

2. 编写测试类，在src/test/java 新建MyBatisTest.java

import entity.TUser;
import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import service.UserServiceI;

import java.util.Date;
import java.util.UUID;


public class MyBatisTest {

    private UserServiceI userService;

    /**
     * 这个before方法在所有的测试方法之前执行，并且只执行一次
     * 所有做Junit单元测试时一些初始化工作可以在这个方法里面进行
     * 比如在before方法里面初始化ApplicationContext和userService
     */
    @Before
    public void before(){
        //使用"spring.xml"和"spring-mybatis.xml"这两个配置文件创建Spring上下文
        ApplicationContext ac = new ClassPathXmlApplicationContext(new String[]{"classpath*:spring.xml","classpath*:spring-mybatis.xml"});
        //从Spring容器中根据bean的id取出我们要使用的userService对象
        userService = (UserServiceI) ac.getBean("userService");
    }

    @Test
    public void testAddUser(){
        ApplicationContext ac = new ClassPathXmlApplicationContext(new String[]{"classpath*:spring.xml","classpath*:spring-mybatis.xml"});
        UserServiceI userService = (UserServiceI) ac.getBean("usrService");
        TUser user = new TUser();
        user.setUserId(UUID.randomUUID().toString().replaceAll("-", ""));
        user.setUserName("testUser");
        user.setUserBirthday(new Date());
        user.setUserSalary(10000D);
        userService.addUser(user);
    }

}

3. 右键->Run"MyBatisTest"

以上，单元测试通过。

四. 在Tomcat上部署

1. 在src/main中 新建包webapp、web.xml、add.jsp 、index.jsp 、update.jsp 。目录结构如下。

web.xml

    
        index.jsp
    

    
        Spring监听器
        org.springframework.web.context.ContextLoaderListener
    
    
    
        contextConfigLocation
        
        classpath:spring.xml,classpath:spring-mybatis.xml
    

add.jsp

<%--
  Created by IntelliJ IDEA.
  User: WUCHAKMING
  Date: 2018/6/7
  Time: 21:43
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>


    



    
A D D
    

        USERNAME: 
        

        

        SALARY: 
        

        

        submit
    

index.jsp

<%--
  Created by IntelliJ IDEA.
  User: WUCHAKMING
  Date: 2018/6/7
  Time: 21:28
  To change this template use File | Settings | File Templates.
--%>
<%@ page language="java" pageEncoding="UTF-8"%>
<%--引入JSTL核心标签库 --%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>



    
    



    <%--遍历lstUsers集合中的User对象 --%>
    
        

    

        
用户ID
        
用户名
        
用户生日
        
工资
        
操作
        
    

            
${user.userId}
            
${user.userName}
            
${user.userBirthday}
            
${user.userSalary}
            
修改
            
删除
        
    

增加
刷新

update.jsp

<%--
  Created by IntelliJ IDEA.
  User: WUCHAKMING
  Date: 2018/6/7
  Time: 22:36
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>


    



<%
    String userId = request.getParameter("userId");
    String userName = request.getParameter("userName");
    String userBirthday = request.getParameter("userBirthday");
    String userSalary = request.getParameter("userSalary");
%>


    
U P D A T E
    

        userId: 
        

        

        USERNAME: 
        

        

        BIRTHDAY: 
        

        

        SALARY: 
        

        

        submit
    

2. Views视图布置完毕，接下来编写Controller控制器。在src/main/java目录下新建包controller 、AddServlet、DeleteServlet、UpdateServlet、UserServlet。目录结构如下：

AddServlet

package controller;

import entity.TUser;
import org.springframework.context.ApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import service.UserServiceI;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Date;
import java.util.UUID;

@WebServlet("/AddServlet")
public class AddServlet extends HttpServlet {

    private UserServiceI userService;

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        TUser user = new TUser();
        user.setUserId(UUID.randomUUID().toString().replaceAll("-", ""));
        user.setUserName(request.getParameter("userName"));
        user.setUserBirthday(new Date());
        user.setUserSalary(Double.parseDouble(request.getParameter("salary")));
        userService.addUser(user);
        request.getRequestDispatcher("/index.jsp").forward(request, response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
           doPost(request, response);
    }

    public void init() throws ServletException {
        //在Servlet初始化时获取Spring上下文对象(ApplicationContext)
        ApplicationContext ac = WebApplicationContextUtils.getWebApplicationContext(this.getServletContext());
        //从ApplicationContext中获取userService
        userService = (UserServiceI) ac.getBean("userService");
    }
}

DeleteServlet

package controller;

import org.springframework.context.ApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import service.UserServiceI;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet("/DeleteServlet")
public class DeleteServlet extends HttpServlet {

    private UserServiceI userService;

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        userService.deleteByPrimaryKey(request.getParameter("userId"));
        request.getRequestDispatcher("/index.jsp").forward(request, response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }

    public void init() throws ServletException {
        //在Servlet初始化时获取Spring上下文对象(ApplicationContext)
        ApplicationContext ac = WebApplicationContextUtils.getWebApplicationContext(this.getServletContext());
        //从ApplicationContext中获取userService
        userService = (UserServiceI) ac.getBean("userService");
    }
}

UpdateServlet

package controller;

import entity.TUser;
import org.springframework.context.ApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import service.UserServiceI;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Date;

@WebServlet("/UpdateServlet")
public class UpdateServlet extends HttpServlet {

    private UserServiceI userService;

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        TUser user = new TUser();
        user.setUserId(request.getParameter("userId"));
        user.setUserName(request.getParameter("userName"));
        user.setUserBirthday(new Date());
        user.setUserSalary(Double.parseDouble(request.getParameter("userSalary")));
        userService.updateByPrimaryKey(user);
        request.getRequestDispatcher("/index.jsp").forward(request, response);

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    public void init() throws ServletException {
        //在Servlet初始化时获取Spring上下文对象(ApplicationContext)
        ApplicationContext ac = WebApplicationContextUtils.getWebApplicationContext(this.getServletContext());
        //从ApplicationContext中获取userService
        userService = (UserServiceI) ac.getBean("userService");
    }
}

UserServlet

package controller;

import entity.TUser;
import org.springframework.context.ApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import service.UserServiceI;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;

@WebServlet("/UserServlet")
public class UserServlet extends HttpServlet {

    private UserServiceI userService;

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //获取所有的用户信息
        List lstUsers = userService.getAllUser();
        request.setAttribute("lstUsers", lstUsers);
        request.getRequestDispatcher("/index.jsp").forward(request, response);
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        this.doGet(request, response);
    }

    public void init() throws ServletException {
        //在Servlet初始化时获取Spring上下文对象(ApplicationContext)
        ApplicationContext ac = WebApplicationContextUtils.getWebApplicationContext(this.getServletContext());
        //从ApplicationContext中获取userService
        userService = (UserServiceI) ac.getBean("userService");
    }
}

3. 部署Tomcat。由于使用了标注@WebServlet，因此Tomcat版本必须在7.0以上。

在编译器右上角，点击Edit Configurations.

添加Tomcat-local

设置部署项

4. 以上，Tomcat部署完成，运行项目

如果遇到浏览器输入地址localhost:8080/无任何响应：

首先删除Tomcat部署，然后点击编译器右侧的Maven Project->Project->LifeCycle->双击clean->双击deploy.

再次按第3步重新部署Tomcat，问题将得到解决。

五. 运行样例

六. 本人小白一个，有错请各位直接指出，大家一起进步！