1、用intellij idea2018搭建ssm框架：SpringMVC+Spring+Mybatis

开发环境：
intellij idea：2018 + maven：3.5.4+ jdk：1.8

在这之前，需要在idea中配置好maven，没有配置的按照下述连接配置
https://blog.csdn.net/nba_linshuhao/article/details/82715485

下面正式开始配置过程

1、新建项目

2、项目目录结构如下（三张图连着看），文件内容往下看
目录颜色不同看步骤3

3、让idea识别目录作用
file----project structure-----modelues
main包下面的java对应Sources，resources对应上面的Resources
test是测试，对应上面的Test Resources
设置之后颜色就跟步骤2的目录颜色一样了

3、pom.xml
直接复制文件到pom.xml中，然后maven会自动下载需要的jar包
（复制文件之后，右下角会提示选中第二个自动下载就好了）

  4.0.0
  com.ssm
  ssm
  war
  1.0-SNAPSHOT
  ChatRobot Maven Webapp
  http://maven.apache.org

  
    
    UTF-8
    UTF-8
    
    4.3.5.RELEASE
    
    3.4.1
  

  

    
    
      javax
      javaee-api
      7.0
    

    
    
      junit
      junit
      4.12
    

    
    
      ch.qos.logback
      logback-classic
      1.2.2
    

    
    
      com.fasterxml.jackson.core
      jackson-databind
      2.8.7
    


    
    
      mysql
      mysql-connector-java
      5.1.41
      runtime
    

    
    
      com.mchange
      c3p0
      0.9.5.2
    

    
    
      org.mybatis
      mybatis
      ${mybatis.version}
    

    
    
      org.mybatis
      mybatis-spring
      1.3.1
    

    
    
      org.springframework
      spring-core
      ${spring.version}
    
    
      org.springframework
      spring-beans
      ${spring.version}
    
    
      org.springframework
      spring-context
      ${spring.version}
    
    
      org.springframework
      spring-jdbc
      ${spring.version}
    
    
      org.springframework
      spring-tx
      ${spring.version}
    
    
      org.springframework
      spring-web
      ${spring.version}
    
    
      org.springframework
      spring-webmvc
      ${spring.version}
    
    
      org.springframework
      spring-test
      ${spring.version}
    

  

  
    ChatRobot
    
      
        org.apache.maven.plugins
        maven-compiler-plugin
        
          
          1.8
          1.8
        
      
    
  

4、logback.xml

    
        
            %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
        
    
    
        
    

5、jdbc.properties

jdbc.driver=com.mysql.jdbc.Driver
#数据库地址
jdbc.url=jdbc:mysql://localhost:3306/mytest?useUnicode=true&characterEncoding=utf8
#用户名
jdbc.username=root
#密码
jdbc.password=root
#最大连接数
c3p0.maxPoolSize=30
#最小连接数
c3p0.minPoolSize=10
#关闭连接后不自动commit
c3p0.autoCommitOnClose=false
#获取连接超时时间
c3p0.checkoutTimeout=10000
#当获取连接失败重试次数
c3p0.acquireRetryAttempts=2

6、spring-mybatis.xml

7、spring-mvc.xml

8、web.xml

  
    index.html
  

  ChatRobot
  ChatRobot_Alpha_0.0.1

  
  
    encodingFilter
    org.springframework.web.filter.CharacterEncodingFilter
    
      encoding
      UTF-8
    
  
  
    encodingFilter
    /*
  

  
  
    SpringMVC
    org.springframework.web.servlet.DispatcherServlet
    
    
      contextConfigLocation
      classpath:spring-*.xml
    
    1
    true
  
  
    SpringMVC
    
    
    /
  

9、准备数据库--------mysql数据库，mysql用户名：root 密码：root
数据库名mytest、表名user
不一样的自行修改。

10、UserController.java

package com.ssm.controller;

import com.ssm.model.User;
import com.ssm.service.IUserService;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Controller
@RequestMapping("/user")
public class UserController {

    @Resource
    private IUserService userService;

    @RequestMapping("/showUser.do")
    public void selectUser(HttpServletRequest request, HttpServletResponse response) throws IOException {
        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("UTF-8");
        long userId = Long.parseLong(request.getParameter("id"));
        User user = this.userService.selectUser(userId);
        ObjectMapper mapper = new ObjectMapper();
        response.getWriter().write(mapper.writeValueAsString(user));
        response.getWriter().close();
    }

}

11、IUserDao.java

package com.ssm.dao;
import com.ssm.model.User;
public interface IUserDao {
   User selectUser(long id);
}

12、User.java

package com.ssm.model;
import java.util.Date;
public class User {
    private long id;
    private String email;
    private String password;
    private String username;
    private String role;
    private int status;
    private Date regTime;
    private String regIp;

    public long getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getRole() {
        return role;
    }
    public void setRole(String role) {
        this.role = role;
    }
    public int getStatus() {
        return status;
    }
    public void setStatus(int status) {
        this.status = status;
    }
    public Date getRegTime() {
        return regTime;
    }
    public void setRegTime(Date regTime) {
        this.regTime = regTime;
    }
    public String getRegIp() {
        return regIp;
    }
    public void setRegIp(String regIp) {
        this.regIp = regIp;
    }
}

13、IUserService.java

package com.ssm.service;

import com.ssm.model.User;


public interface IUserService {

    User selectUser(long userId);

    int insert(User user);

}

14、UserServiceImpl.java

package com.ssm.service.impl;

import com.ssm.dao.IUserDao;
import com.ssm.model.User;
import com.ssm.service.IUserService;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

@Service("userService")
public class UserServiceImpl implements IUserService {

    @Resource
    private IUserDao userDao;

    public User selectUser(long userId) {
        return this.userDao.selectUser(userId);
    }

    @Override
    public int insert(User user) {
        return 0;
    }

}

15、UserDao.xml

    
        SELECT * FROM user WHERE id = #{id}
    

16、新建测试类，测试mybatis
IUserDaoTest.java

package com.ssm.daoTest;
import com.ssm.dao.IUserDao;
import com.ssm.model.User;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

// 加载spring配置文件
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({"classpath:spring-mybatis.xml"})
public class IUserDaoTest {

    @Autowired
    private IUserDao dao;

    @Test
    public void testSelectUser() throws Exception {
        long id = 1;
        User user = dao.selectUser(id);
        System.out.println(user.getUsername());
    }

}

17、运行测试
上面的测试代码的目的是：从数据库中查询id为1的数据。所以运行测试之前需要在数据库中插入一两条数据，以免报错

测试结果：idea输出面板会输出id为1的用户的名字

18、新建index.html页面来测试SpringMVC和Mybatis
index.html

    
    



Hello World!
onclick test

19、配置tomact，右上角edit configurations

20、运行Tomact

点击按钮

21、还可以直接在地址栏中输入url，同样可以得到上面的结果
http://localhost:8080/user/showUser.do?id=1

可能出现的问题：
1、数据库名字密码错误
2、数据库中没有id为1的数据
3、mapper映射文件UserDao.xml中的namespace和包dao的路径不一样

整个项目的下载地址：
https://download.csdn.net/download/nba_linshuhao/10680908

Spring-mybatis的配置详解
https://blog.csdn.net/happy_wu/article/details/61216112