用SpringBoot+MySql+JPA实现对数据库的增删改查和分页

2023-08-16 20:18:04

使用SpringBoot+Mysql+JPA实现对数据库的增删改查和分页

JPA是Java Persistence API的简称，中文名Java持久层API，是JDK 5.0注解或XML描述对象－关系表的映射关系，并将运行期的实体对象持久化到数据库中。
使用Springboot和jpa对数据库进行操作时，能够大大减少我们的工作量，在jpa中，已经在底层封装好了增删查的功能和sql语句，可以使我们进行快速开发

项目流程

一、新建一个项目

二、配置文件

#数据源配置

spring.datasource.type=com.alibaba.druid.pool.DruidDataSource

spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver

spring.datasource.url=jdbc:mysql://localhost:3306/stu?useSSL=false&useUnicode=true&characterEncoding=utf-8&autoReconnect=true&serverTimezone=Asia/Shanghai

spring.datasource.username=root

spring.datasource.password=root

spring.datasource.initialSize=20

spring.datasource.minIdle=50

spring.datasource.maxActive=500

#上下文配置

server.port=8888

server.servlet.context-path=/stu

#配置jpa

#帮我们自动生成表结构

spring.jpa.properties.hibernate.hbm2ddl.auto=update

spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect

spring.jpa.show-sql= true

spring.jpa.properties.hibernate.enable_lazy_load_no_trans=true

<?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">

    <modelVersion>4.0.0</modelVersion>

    <parent>

        <groupId>org.springframework.boot</groupId>

        <artifactId>spring-boot-starter-parent</artifactId>

        <version>2.1.4.RELEASE</version>

        <relativePath/> <!-- lookup parent from repository -->

    </parent>

    <groupId>com.kude.stu</groupId>

    <artifactId>kudestu</artifactId>

    <version>0.0.1-SNAPSHOT</version>

    <name>kudestu</name>

    <description>Demo project for Spring Boot</description>

    <properties>

        <java.version>1.8</java.version>

    </properties>

    <dependencies>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-data-jpa</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-web</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-devtools</artifactId>

            <scope>runtime</scope>

        </dependency>

        <dependency>

            <groupId>mysql</groupId>

            <artifactId>mysql-connector-java</artifactId>

            <scope>runtime</scope>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-test</artifactId>

            <scope>test</scope>

        </dependency>

        <!-- druid数据库连接池-->

        <dependency>

            <groupId>com.alibaba</groupId>

            <artifactId>druid</artifactId>

            <version>1.1.10</version>

        </dependency>

        <!-- https://mvnrepository.com/artifact/com.github.pagehelper/pagehelper-spring-boot-starter -->

        <dependency>

            <groupId>com.github.pagehelper</groupId>

            <artifactId>pagehelper-spring-boot-starter</artifactId>

            <version>1.2.10</version>

        </dependency>

    </dependencies>

    <build>

        <plugins>

            <plugin>

                <groupId>org.springframework.boot</groupId>

                <artifactId>spring-boot-maven-plugin</artifactId>

            </plugin>

        </plugins>

    </build>

</project>

三、Mysql数据库

新建一个数据库stu,创建student表和user表

四、后端实现

student实体类

package com.kude.stu.kudestu.stu.entity;

import javax.persistence.*;

import javax.xml.soap.Name;

@Entity

@Table(name = "student")

public class Student {

    @Id

    @GeneratedValue(strategy = GenerationType.IDENTITY)

    private Integer id;

    private String name;

    private int age;

    private String sex;

    @Override

    public String toString() {

        return "Student{" +

                "id=" + id +

                ", name='" + name + '\'' +

                ", age=" + age +

                ", sex='" + sex + '\'' +

                '}';

    }

    public Integer getId() {

        return id;

    }

    public void setId(Integer id) {

        this.id = id;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public int getAge() {

        return age;

    }

    public void setAge(int age) {

        this.age = age;

    }

    public String getSex() {

        return sex;

    }

    public void setSex(String sex) {

        this.sex = sex;

    }

    public Student() {

    }

}

　　user实体类

package com.kude.stu.kudestu.stu.entity;

import javax.persistence.*;

@Entity

@Table(name="user")

public class User {

    @Id

    @GeneratedValue(strategy = GenerationType.IDENTITY)

    private int id;

    private String username;

    private String password;

    public User() {

    }

    @Override

    public String toString() {

        return "User{" +

                "id=" + id +

                ", username='" + username + '\'' +

                ", password='" + password + '\'' +

                '}';

    }

    public int getId() {

        return id;

    }

    public void setId(int id) {

        this.id = id;

    }

    public String getUsername() {

        return username;

    }

    public void setUsername(String username) {

        this.username = username;

    }

    public String getPassword() {

        return password;

    }

    public void setPassword(String password) {

        this.password = password;

    }

}

StudentDao接口

package com.kude.stu.kudestu.stu.dao;

import com.kude.stu.kudestu.stu.entity.Student;

import org.springframework.data.jpa.repository.JpaRepository;

import org.springframework.data.jpa.repository.Query;

import org.springframework.data.repository.query.Param;

import java.util.List;

public interface StudentDao extends JpaRepository<Student,Integer> {

        Student findStuById(Integer id);

        @Query(name = "findStuByName",nativeQuery = true,value = "select * from student where name=:name ")

        List<Student> findStuByName(@Param("name") String name);

}

UserDao接口

package com.kude.stu.kudestu.stu.dao;

import com.kude.stu.kudestu.stu.entity.User;

import org.springframework.data.jpa.repository.JpaRepository;

import org.springframework.data.jpa.repository.Query;

import org.springframework.data.repository.query.Param;

public interface UserDao extends JpaRepository<User,Integer> {

    /**

     * 根据id查询

     */

    User findUserById(int id);

    @Query(name = "login",nativeQuery = true,value = "select * from user where username=:username and password=:password")

    User login(@Param("username") String username,@Param("password") String password);

}

StudentService接口

package com.kude.stu.kudestu.stu.service;

import com.kude.stu.kudestu.stu.entity.Student;

import org.springframework.data.domain.Page;

import java.util.List;

public interface StudentService {

    Student save(Student student);

    Student update(Student student);

    void delete(Integer id);

    Student findStuById(Integer id);

    List<Student> findStuByName(String name);

    /**

     * 分页查询所有数据

     * @param page  当前页

     * @param pageSize  每页记录数

     * @return

     */

    Page<Student> findAll(int page,int pageSize);

}

StudentServiceImpl实现类

package com.kude.stu.kudestu.stu.service;

import com.kude.stu.kudestu.stu.dao.StudentDao;

import com.kude.stu.kudestu.stu.entity.Student;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.data.domain.Page;

import org.springframework.data.domain.PageRequest;

import org.springframework.data.domain.Pageable;

import org.springframework.stereotype.Service;

import java.util.List;

@Service

public class StudentServiceImpl implements StudentService {

    @Autowired

    private StudentDao studentDao;

    @Override

    public Student save(Student student) {

        return studentDao.save(student);

    }

    @Override

    public Student update(Student student) {

        return studentDao.save(student);

    }

    @Override

    public void delete(Integer id) {

        studentDao.deleteById(id);

    }

    @Override

    public Student findStuById(Integer id) {

        return studentDao.findStuById(id);

    }

    @Override

    public List<Student> findStuByName(String name) {

        return studentDao.findStuByName(name);

    }

    @Override

    public Page<Student> findAll(int page, int pageSize) {

        Pageable pageable = PageRequest.of(page,pageSize);

        return studentDao.findAll(pageable);

    }

}

UserService接口

package com.kude.stu.kudestu.stu.service;

import com.kude.stu.kudestu.stu.entity.User;

import java.util.List;

public interface UserService {

    List<User> findAll();

    User findUserById(int id);

    User save(User user);

    User update(User user);

    User login(String username,String password);

}

UserServiceImpl实现类

package com.kude.stu.kudestu.stu.service;

import com.kude.stu.kudestu.stu.dao.UserDao;

import com.kude.stu.kudestu.stu.entity.User;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Service;

import java.util.List;

@Service

public class UserServiceImpl implements UserService {

    @Autowired

    private UserDao userDao;

    @Override

    public List<User> findAll() {

        return userDao.findAll();

    }

    @Override

    public User findUserById(int id) {

        return userDao.findUserById(id);

    }

    @Override

    public User save(User user) {

        return userDao.save(user);

    }

    @Override

    public User login(String username, String password) {

        return userDao.login(username,password);

    }

    @Override

    public User update(User user) {

        return null;

    }

}

StudentController类

package com.kude.stu.kudestu.stu.controller;

import com.kude.stu.kudestu.stu.entity.Student;

import com.kude.stu.kudestu.stu.service.StudentService;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.data.domain.Page;

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

import javax.servlet.http.HttpServletResponse;

import java.util.List;

@RestController

@RequestMapping("/s")

public class StudentController {

    @Autowired

    private StudentService studentService;

    /**

     * 添加学生

     * @param student  要添加的学生对象

     * @return

     */

    @PostMapping("/add")

    public Student save(Student student){

        return studentService.save(student);

    }

    /**

     * 修改学生

     * @param student  要修改的学生对象

     * @return

     */

    @PostMapping("/update")

    public Student update(Student student){

        return studentService.save(student);

    }

    /**

     * 删除学生

     * @param id 要删除学生对象的id

     */

    @GetMapping("/del/{id}")

    public String del(@PathVariable Integer id){

        studentService.delete(id);

        return "yes";

    }

    /**

     * 通过姓名查询学生信息

     * @param name 要查询的学生的姓名

     * @return

     */

    @GetMapping("/findByName/{name}")

    public List<Student> findStuByName(@PathVariable String name){

        return studentService.findStuByName(name);

    }

    /**

     * 分页查询

     * @param page

     *

     * @return

     */

    @GetMapping("/query")

    public Page<Student> findByPage(Integer page, HttpServletResponse response){

        response.setHeader("Access-Control-Allow-Origin","*");

        if(page==null||page<=0){

            page=0;

        }else {

            page -=1;

        }

        return studentService.findAll(page,5);

    }

}

UserController类

package com.kude.stu.kudestu.stu.controller;

import com.kude.stu.kudestu.stu.entity.User;

import com.kude.stu.kudestu.stu.service.UserService;

import org.springframework.beans.factory.annotation.Autowired;

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

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

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

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

import java.util.List;

/**

 *处理用户信息的控制层

 * @author 张玉贤

 * */

@RestController

@RequestMapping("/user")

public class UserController {

    @Autowired

    private UserService userService;

    /**

     *查询用户的方法

     *

     */

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

    public List<User> findAll(){

        return userService.findAll();

    }

    /**

     * 根据id查询用户

     */

    @RequestMapping(value = "/findById")

    public User findUserById(int id){

        return userService.findUserById(id);

    }

    /**

     * 注册用户

     */

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

    public User reg(User user){

        return userService.save(user);

    }

    /**

     * 用户登录

     */

    @PostMapping("/login")

    public User login(String username,String password){

        return userService.login(username,password);

    }

}

五、前端分页实现

新建一个项目

百度搜索菜鸟教程并打开

在js目录下新建一个jquery.js

将所有内容全选复制粘贴进js目录下的jquery.js中保存即可

index.html

<!DOCTYPE html>

<html>

	<head>

		<meta charset="utf-8">

		<title></title>

		<script src="js/jquery.js" type="text/javascript" charset="utf-8"></script>

		<script type="text/javascript">

			var page = 1;

			var tp = 0;

			$(function(){

				showData();

			});

			function upPage(){

				if(page>1){

					page--;

					showData();

				}

			}

			function downPage(){

				if(page<tp){

					page++;

					showData();

				}

			}

			function showData(){

				$.ajax({

					url:'http://localhost:8888/stu/s/query?page='+page,

					success:function(result){

						var rel = result.content;

						tp = result.totalPages;

						var htmlStr = "<table width='80%' algin='center' border='1'>"+

									"<tr><th>ID</th><th>姓名</th><th>年龄</th><th>性别</th><th>操作</th></tr>";

						for(var i=0;i<rel.length;i++){

							var stu = rel[i];

							htmlStr += "<tr><td>"+stu.id+"</td><td>"+stu.name+"</td><td>"+stu.age+"</td><td>"+stu.sex+"</td>"+

							"<td><a href=''>修改</a> <a href='http://localhost:8888/stu/s/del/"+stu.id+"'>删除</a></td></tr>";

						}

						htmlStr += "</table>";

						$("#show").html(htmlStr);

					}

				});

			}

		</script>

	</head>

	<body>

		<h1 style="text-align: center;">学生管理系统</h1>

		<hr>

		<a href="add.html">添加学生</a>

		<div id="show">

		</div>

		<a href="javascript:upPage();">上一页</a>  <a href="javascript:downPage();">下一页</a>

	</body>

</html>

add.html

<!DOCTYPE html>

<html>

	<head>

		<meta charset="utf-8">

		<title></title>

	</head>

	<body>

		<h1>添加学生</h1>

		<hr>

		<form action="http://localhost:8888/stu/s/add" method="post">

			<p>

				姓名：<input type="text" name="name" />

			</p>

			<p>

				年龄：<input type="text" name="age" />

			</p>

			<p>

				性别：

				<input type="radio" name="sex" value="男"  checked />男

				<input type="radio" name="sex" value="女" />女

			</p>

			<p>

				<input type="submit" value="保存" />

			</p>

		</form>

	</body>

</html>