使用SpringMVC实现对一个表的增删改查

视频课程里面已经教了增删查三个功能，主要修改功能是自己实现的。

思路：增加一个修改数据的按钮，点击时将这一条数据的id作为参数，查询到数据库里对应的数据，返回到专门的修改页面上，修改页面可以复制自增加页面来使用。

 

 

 

 

 

点击更新以后就执行更新方法，再重定向回查询所有用户的主页面。

中间遇到的问题是，使用request传递不了查询出来的单个Teacher对象到修改页面，经过百度以后，使用request.getSession().setAttribute解决：1、如果你是在同一个服务器（容器）里做的转向工作。那么可以这样
把request.setAttribute(“cha”, cha);改成request.getSession().setAttribute(“cha”, cha);
然后<%Object a = (Object)request.getSession().getAttribute(“cha”);%>其他不变。

参考链接：https://blog.csdn.net/qq_33551891/article/details/88988181

 

 

项目创建步骤1，先在resources文件夹下配置好SpringMVC,Spring,Mybaits的相关配置文件:

db.properties

jdbc.url=jdbc:mysql://localhost:3306/mybatis?serverTimezone=GMT%2B8&useSSL=false
jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.username=root
jdbc.password=zengyu1234

SqlMapConfig.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <typeAliases>
        <package name="com.xzit.entity"/>
    </typeAliases>
    <mappers>
        <package name="com.xzit.mapper"/>
    </mappers>
</configuration>

springmvc.xml

<?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.alibaba.com/schema/stat"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.alibaba.com/schema/stat http://www.alibaba.com/schema/stat.xsd">
    <!--自动扫描-->
    <context:component-scan base-package="com.xzit"></context:component-scan>
    <!--处理器映射器和适配器-->
    <mvc:annotation-driven></mvc:annotation-driven>
</beans>

applicationContext.xml

<?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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       https://www.springframework.org/schema/context/spring-context.xsd">
    <!--对应db.properties文件-->
    <context:property-placeholder location="classpath:db.properties"></context:property-placeholder>
    <!--数据源-->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
        <property name="url" value="${jdbc.url}"></property>
        <property name="username" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>
    <!--配置SqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <property name="configLocation" value="classpath:SqlMapConfig.xml"></property>
    </bean>
    <!--对Mapper的扫描-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>
        <!--配置Mapper文件的基准包-->
        <property name="basePackage" value="com.xzit.mapper"></property>
    </bean>
</beans>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
                      http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
  <!--spring配置-->
  <!--配置加载ApplicationContext-->
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  <!--配置spring文件的地址-->
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext.xml</param-value>
  </context-param>

  <!--springmvc配置-->
  <!--配置前端控制器-->
  <servlet>
    <servlet-name>mvc</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <!--配置初始化参数，指定springmvc配置文件的位置-->
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:springmvc.xml</param-value>
    </init-param>
  </servlet>
  <servlet-mapping>
    <servlet-name>mvc</servlet-name>
    <!--过滤除jsp以外的资源-->
    <url-pattern>/</url-pattern>
  </servlet-mapping>
</web-app>

pom.xml

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

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springmvc_project</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.xzit</groupId>
    <artifactId>day7_job</artifactId>
    <packaging>war</packaging>

    <name>day7_job Maven Webapp</name>
    <!-- FIXME change it to the project's website -->
    <url>http://www.example.com</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>
        <!--spring-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.3.15</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>5.3.15</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.15</version>
        </dependency>
        <!--druid数据源-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.8</version>
        </dependency>
        <!--mysql驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.28</version>
        </dependency>
        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.22</version>
        </dependency>
        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.9</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.7</version>
        </dependency>
        <!--servlet api-->
        <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
        <!--jsp api-->
        <!-- https://mvnrepository.com/artifact/javax.servlet.jsp/javax.servlet.jsp-api -->
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>javax.servlet.jsp-api</artifactId>
            <version>2.3.3</version>
            <scope>provided</scope>
        </dependency>
        <!--引用json格式依赖-->
        <!-- https://mvnrepository.com/artifact/javax.annotation/jsr250-api -->
        <dependency>
            <groupId>javax.annotation</groupId>
            <artifactId>jsr250-api</artifactId>
            <version>1.0</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.13.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.13.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.13.2</version>
        </dependency>
    </dependencies>
    <build>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>
    </build>
</project>

 

项目创建步骤2，创建好实体类，Mapper和service类，以及解决中文乱码问题的过滤器类：

package com.xzit.entity;

import lombok.Data;
import lombok.experimental.Accessors;

@Data
@Accessors(chain = true)
public class Teacher {
    private int id;
    private String name;
    private String addr;
    private int age;
    private String job;
    private int sal;
}

package com.xzit.mapper;

import com.xzit.entity.Teacher;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface TeacherMapper {
    /*增加老师的方法*/
    @Insert("insert into teacher values(null,#{name},#{addr},#{age},#{job},#{sal})")
    void save(Teacher teacher);

    /*删除老师的方法*/
    @Delete("delete from teacher where id=#{id}")
    void delete(int id);

    /*修改老师的方法*/
    @Update("update teacher t set t.name=#{name},t.addr=#{addr},t.age=#{age},t.job=#{job},t.sal=#{sal} where t.id=#{id}")
    void update(Teacher teacher);

    /*查询老师的方法*/
    @Select("select * from teacher")
    List<Teacher> selectList();

    /*根据id查询老师的方法*/
    @Select("select * from teacher where id=#{id}")
    Teacher selectTeacher(int id);
}

package com.xzit.service;

import com.xzit.entity.Teacher;

import java.util.List;

public interface TeacherService {
    void save(Teacher teacher);
    void delete(int id);
    void update(Teacher teacher);
    List<Teacher> selectList();
    Teacher selectTeacher(int id);
}

package com.xzit.service;

import com.xzit.entity.Teacher;
import com.xzit.mapper.TeacherMapper;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;

@Service
public class TeacherServiceImpl implements TeacherService {

    @Resource
    private TeacherMapper teacherMapper;

    @Override
    public void save(Teacher teacher) {
        teacherMapper.save(teacher);
    }

    @Override
    public void delete(int id) {
        teacherMapper.delete(id);
    }

    @Override
    public void update(Teacher teacher) {
        teacherMapper.update(teacher);
    }

    @Override
    public List<Teacher> selectList() {
        return teacherMapper.selectList();
    }

    @Override
    public Teacher selectTeacher(int id) {
        return teacherMapper.selectTeacher(id);
    }
}

package com.xzit.filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;

/**
 * 配置过滤器解决servlet请求传输的中文乱码的问题
 */
@WebFilter("/*")
public class EncodingFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        servletRequest.setCharacterEncoding("utf-8");
        servletResponse.setCharacterEncoding("utf-8");
        filterChain.doFilter(servletRequest,servletResponse);
    }
}

 

项目创建步骤3，写完Controller类和jsp页面

package com.xzit.controller;

import com.xzit.entity.Teacher;
import com.xzit.service.TeacherService;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.Principal;
import java.util.*;

@Controller
public class TeacherController {
    @Resource
    private TeacherService teacherService;

    /*增*/
    @PostMapping("save")
    public String save(Teacher teacher){
        teacherService.save(teacher);
        //重定向
        return "redirect:select";
    }

    /*删*/
    @RequestMapping("delete/{id}")
    public String delete(@PathVariable int id){
        teacherService.delete(id);
        return "redirect:/select";
    }

    /*改*/
    @PostMapping("update")
    public String update(Teacher teacher){
        teacherService.update(teacher);
        //重定向
        return "redirect:select";
    }

    /*查*/
    @GetMapping("select")
    public String select(HttpServletRequest request){
        List<Teacher> list=teacherService.selectList();
        request.setAttribute("list",list);
        return "list.jsp";
    }

    /*按照id查询老师到修改页面*/
    @GetMapping ("updateId/{id}")
    public String selectTeacher(@PathVariable("id") Integer id,HttpServletRequest request){
        Teacher teacher=teacherService.selectTeacher(id);
        request.getSession().setAttribute("teacher",teacher);
        return "redirect:/update.jsp";
    }
}

<%--
  Created by IntelliJ IDEA.
  User: zengy
  Date: 2022/7/16
  Time: 22:37
  To change this template use File | Settings | File Templates.
--%>
<%@ page import="java.util.List" %>
<%@ page import="com.xzit.entity.Teacher" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
    <style>
        table,td{
            border: 1px solid black;
            border-collapse: collapse;
        }
        table{
            margin:0 auto;
            text-align: center;
            width: 700px;
        }
    </style>
</head>
<body>
<table>
    <tr>
        <td>序号</td>
        <td>姓名</td>
        <td>地址</td>
        <td>年龄</td>
        <td>职位</td>
        <td>工资</td>
        <td>操作</td>
    </tr>
    <%List<Teacher> list= (List<Teacher>) request.getAttribute("list");
        int x=1;
        for (Teacher teacher:list){%>
    <tr>
        <td><%=x++%></td>
        <td><%=teacher.getName()%></td>
        <td><%=teacher.getAddr()%></td>
        <td><%=teacher.getAge()%></td>
        <td><%=teacher.getJob()%></td>
        <td><%=teacher.getSal()%></td>
        <td><a href="javascript:;" onclick="doDel(<%=teacher.getId()%>)">删除数据</a></td>
        <td><a href="javascript:;" onclick="doPost(<%=teacher.getId()%>)">修改数据</a></td>
    </tr>
    <%}%>
</table>
<script>
    function doDel(id){
        if (confirm("确定删除吗？"))
            location="delete/"+id
    }

    function doPost(id){
        /*alert(id)*/
        location="updateId/"+id
    }
</script>
</body>
</html>

<%--
  Created by IntelliJ IDEA.
  User: zengy
  Date: 2022/7/16
  Time: 23:38
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <form action="save" method="post">
        <div>姓名:<input type="text" name="name"></div>
        <div>地址:<input type="text" name="addr"></div>
        <div>年龄:<input type="number" name="age"></div>
        <div>职位:<input type="text" name="job"></div>
        <div>工资:<input type="number" name="sal"></div>
        <div>
            <button type="submit">提交</button>
        </div>
    </form>
</body>
</html>

<%@ page import="com.xzit.entity.Teacher" %><%--
  Created by IntelliJ IDEA.
  User: zengy
  Date: 2022/7/16
  Time: 23:38
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>更新老师</title>
</head>
<body>
<%Teacher teacher = (Teacher) request.getSession().getAttribute("teacher"); %>
    <form action="update" method="post">
        <div>姓名:<input type="text" name="id" value="<%=teacher.getId()%>"></div>
        <div>姓名:<input type="text" name="name" value="<%=teacher.getName()%>"></div>
        <div>地址:<input type="text" name="addr" value="<%=teacher.getAddr()%>"></div>
        <div>年龄:<input type="number" name="age" value="<%=teacher.getAge()%>"></div>
        <div>职位:<input type="text" name="job" value="<%=teacher.getJob()%>"></div>
        <div>工资:<input type="number" name="sal" value="<%=teacher.getSal()%>"></div>
        <div>
            <button type="submit">更新</button>
        </div>
    </form>
</body>
</html>