一、前言

如果还不了解剧情，请返回第3集的剧情             

二、在Eclipse中创建Maven类型的SSM项目

2.1：SSM简介

SSM（Spring+SpringMVC+MyBatis）框架集由Spring、SpringMVC、MyBatis三个开源框架整合而成，常作为数据源较简单的web项目的框架。其中spring是一个轻量级的控制反转（IoC）和面向切面（AOP）的容器框架。SpringMVC分离了控制器、模型对象、分派器以及处理程序对象的角色，这种分离让它们更容易进行定制。MyBatis是一个支持普通SQL查询，存储过程和高级映射的优秀持久层框架

2.2：搭建maven类型的SSM项目的步骤

2.2.1：在pom.xml文件引入SSM所需要的包

        
       
        4.0.0
         
       
        king.weixin
         
       
        KingWeixin
         
       
        war
         
       
        0.0.1-SNAPSHOT
         
       
        KingWeixin Maven Webapp
         
       
        http://maven.apache.org
         
         
           
        
         UTF-8
            
        
         1.8
            
        
         4.3.5.RELEASE
            
        
         1.7.2
            
        
         UTF-8
          
         
         
         
            
              
         
          junit
               
         
          junit
               
         
          3.8.1
               
         
          test
             
          
          
            
              
         
          org.springframework
               
         
          spring-webmvc
               
         
          ${org.springframework-version}
             
                
              
         
          org.springframework
               
         
          spring-context-support
               
         
          ${org.springframework-version}
             
                
              
         
          org.springframework
               
         
          spring-tx
               
         
          ${org.springframework-version}
             
            
              
         
          org.springframework
               
         
          spring-jdbc
               
         
          ${org.springframework-version}
             
            
              
         
          org.springframework
               
         
          spring-web
               
         
          ${org.springframework-version}
             
            
              
         
          org.springframework
               
         
          spring-context
               
         
          ${org.springframework-version}
               
                 
                  
                    
           
            commons-logging
                     
           
            commons-logging
                   
                
             
          
          
            
              
         
          mysql
               
         
          mysql-connector-java
               
         
          5.1.31
             
            
              
         
          commons-dbcp
               
         
          commons-dbcp
               
         
          1.4
             
            
              
         
          org.mybatis
               
         
          mybatis-spring
               
         
          1.3.0
             
            
              
         
          org.mybatis
               
         
          mybatis
               
         
          3.4.1
             
              
          
            
              
         
          javax.servlet
               
         
          javax.servlet-api
               
         
          3.0.1
               
         
          provided
             
          
            
            
              
         
          commons-configuration
               
         
          commons-configuration
               
         
          1.9
             
            
              
         
          commons-fileupload
               
         
          commons-fileupload
               
         
          1.3.2
             
            
              
         
          commons-io
               
         
          commons-io
               
         
          2.5
             
            
              
         
          commons-net
               
         
          commons-net
               
         
          3.5
             
            
              
         
          org.apache.commons
               
         
          commons-lang3
               
         
          3.2
             
          
          
            
              
         
          org.apache.logging.log4j
               
         
          log4j-api
               
         
          2.10.0
             
            
              
         
          org.apache.logging.log4j
               
         
          log4j-core
               
         
          2.10.0
             
            
            
              
         
          org.apache.logging.log4j
               
         
          log4j-web
               
         
          2.10.0
             
              
              
                  
         
          org.apache.logging.log4j
                   
         
          log4j-jcl
                   
         
          2.10.0
               
              
              
                  
         
          org.apache.logging.log4j
                   
         
          log4j-slf4j-impl
                   
         
          2.10.0
               
          
            
              
         
          javax.servlet
               
         
          jstl
               
         
          1.2
           
             
         
         
           
        
         KingWeixin
            
              
                 
          
           org.apache.maven.plugins
                  
          
           maven-compiler-plugin
                  
                    
           1.8          
           
            1.8
                   
                
               
          
         
       
      

2.2.2：修改web.xml文件

      
          
           
       
        KingWeixin
           
           
               
        
         CharacterEncodingFilter
                
        
         org.springframework.web.filter.CharacterEncodingFilter
                
                    
         
          encoding
                     
         
          utf-8
                 
                
                    
         
          forceEncoding
                     
         
          true
                 
            
           
               
        
         CharacterEncodingFilter
                
        
         /*
            
            
                
           
               
        
         contextConfigLocation
                
        
         classpath*:/config/spring-*.xml
            
           
               
           
               
        
         org.springframework.web.context.ContextLoaderListener
            
            
               
           
               
        
         springDispatcherServlet
                
        
         org.springframework.web.servlet.DispatcherServlet
                
                    
         
          contextConfigLocation
                     
         
          classpath:/config/spring-mvc.xml
                 
                
        
         1
            
           
               
        
         springDispatcherServlet
                
        
         /
            
            
                   
      

2.2.2：新建SSM相关文件

首先，创建spring-mvc.xml主要配置文件

其次创建spring-common.xml通用性配置文件

      
          
           
           
           
           
           
           
           
           
           
               
                    
         
          com.mysql.jdbc.Driver
                 
                
                    
         
          jdbc:mysql://数据服务器IP:3306/king?user=root&password=密码&useUnicode=true&characterEncoding=utf-8            
                 
                
                
                
                
                
                
                
                
                
                
            
           
           
               
                
            
           
           
               
                
            
           
           
               
            
           
           
       
      

最后创建mybatis-config.xml数据持久层配置文件

关系，两个Spring文件会在web.xml中引入，mybatis-config文件会在sping定义数据源配置的spring-common.xml文件中引入，具体可以看代码，截止目前，项目搭建完毕，Maven-update  project的话，系统会根据pom.xml自动下载相关jar包，这就是Maven的好处

2.3：SSM查询实例

（1）新建entity类User.java

package com.king.weixin.entity;/** * @author KING * 2018-6-8 16:00:06 */public class User {    private int id;    private String age;    private String userName;    public User(){        super();    }    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getAge() {        return age;    }    public void setAge(String age) {        this.age = age;    }    public String getUserName() {        return userName;    }    public void setUserName(String userName) {        this.userName = userName;    }    public User(int id, String age, String userName) {        super();        this.id = id;        this.age = age;        this.userName = userName;    }}

（2）新建UserMapper.java接口类

package com.king.weixin.mapper;import java.util.List;import com.king.weixin.entity.User;public interface UserMapper {    void save(User user);    boolean update(User user);    boolean delete(int id);    User findById(int id);    List
      
        findAll();}
      

（3）新建userMapper.xml

      
      
              
       
                insert into t_user(user_name,user_age) values(#{userName},#{age})    
           
       
                update t_user set user_name=#{userName},user_age=#{age} where user_id=#{id}    
               
       
                delete from t_user where user_id=#{id}    
           
             
               select user_id id,user_name userName,user_age age from t_user where user_id=#{id}        
               select user_id id,user_name userName,user_age age from t_user        
      

(4)新建UserService.java接口类

package com.king.weixin.service;import java.util.List;import com.king.weixin.entity.User;public interface UserService {    void save(User user);    boolean update(User user);    boolean delete(int id);    User findById(int id);    List
      
        findAll();}
      

(5)新建UserServiceImpl.java实现类

package com.king.weixin.service;import java.util.List;import javax.annotation.Resource;import org.springframework.stereotype.Service;import org.springframework.transaction.annotation.Transactional;import com.king.weixin.mapper.UserMapper;import com.king.weixin.entity.User;import com.king.weixin.service.UserService;@Service@Transactional  //此处不再进行创建SqlSession和提交事务，都已交由spring去管理了public class UserServiceImpl implements UserService {        @Resource    private UserMapper mapper;    public boolean delete(int id) {                return mapper.delete(id);    }    public List
      
        findAll() {        List
       
         findAllList = mapper.findAll();        return findAllList;    }    public User findById(int id) {        User user = mapper.findById(id);                return user;    }    public void save(User user) {        mapper.save(user);    }    public boolean update(User user) {        return mapper.update(user);    }        }
       
      

(6)新建UserController.java控制类

package com.king.weixin.controller;import java.io.IOException;import java.io.PrintWriter;import java.util.List;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import com.king.weixin.entity.User;import com.king.weixin.service.UserService;@Controller@RequestMapping("/user")public class UserController {    @Autowired    private UserService userService;        /**     * 获取所有用户列表     * @param request     * @return     */    @RequestMapping("/getAllUser")    public String getAllUser(HttpServletRequest request){                System.out.println("访问的是我");        List
      
        findAll = userService.findAll();                request.setAttribute("userList", findAll);        return "/index";    }        /**     * 跳转到添加用户界面     * @param request     * @return     */    @RequestMapping("/toAddUser")    public String toAddUser(HttpServletRequest request){                return "/addUser";    }    /**     * 添加用户并重定向     * @param user     * @param request     * @return     */    @RequestMapping("/addUser")    public String addUser(User user,HttpServletRequest request){        userService.save(user);        return "redirect:/user/getAllUser";    }        /**     *编辑用户     * @param user     * @param request     * @return     */    @RequestMapping("/updateUser")    public String updateUser(User user,HttpServletRequest request){                        if(userService.update(user)){            user = userService.findById(user.getId());            request.setAttribute("user", user);            return "redirect:/user/getAllUser";        }else{            return "/error";        }    }    /**     * 根据id查询单个用户     * @param id     * @param request     * @return     */    @RequestMapping("/getUser")    public String getUser(int id,HttpServletRequest request){                request.setAttribute("user", userService.findById(id));        return "/editUser";    }    /**     * 删除用户     * @param id     * @param request     * @param response     */    @RequestMapping("/delUser")    public void delUser(int id,HttpServletRequest request,HttpServletResponse response){        String result = "{\"result\":\"error\"}";                if(userService.delete(id)){            result = "{\"result\":\"success\"}";        }                response.setContentType("application/json");                try {            PrintWriter out = response.getWriter();            out.write(result);        } catch (IOException e) {            e.printStackTrace();        }    }        @RequestMapping("/GoLogin")    public String GoLogin(HttpServletRequest request,HttpServletResponse response)    {            return "/login";               }    @RequestMapping("/CheckLogin")    public void CheckLogin(HttpServletRequest request,HttpServletResponse response) throws IOException    {            String sysusername="king";            String syspassword="123456";            String username=request.getParameter("userName");            String password=request.getParameter("passWord");            System.out.println("用户名："+username);            System.out.println("密码："+password);            HttpSession session=request.getSession();            if(username.equals(sysusername)&&password.equals(syspassword))            {                session.setAttribute("username",username );                response.getWriter().write("success");            }            else            {                response.getWriter().write("err");            }    }}
      

后台的类已创建完成，下面我们新建一个index.jsp页面做测试，页面内容如下，这里我引入了jstl标签，具体代码请看下面的代码

<%@ page language="java" contentType="text/html; charset=utf8"    pageEncoding="utf8"%><%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> 
      
Hello，world
查询所有用户    
                    
      
      
           
        
             
用户编号
         
年龄
         
姓名
            
            
                            
${user.id}
                            
${user.age}
                            
${user.userName}
                           
                   
      

启动项目，访问如下图所示，访问到首页

点击查询所有用户按钮

后台我在UserController里面的getAllUser方法做了打印，可以看到请求已经到了Controller里面，实战结束