Springboot和Jpa实现学生CRUD操作代码实例

前期准备

使用idea新建个SpringBoot项目

在数据库中建student表

建包

1.编写entity包下实体类Student

（一个Javabean规范）

package com.example.stu.kudestu.stu.entity;import javax.persistence.*;@Entity@Table(name = 'student')//@Entity 应用在实体类上 @Table(name = 'student') 应用在实体类上,并且name属性为数据库表名public class Student { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) //ID自增 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 Student() { } 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; }}

2.编写dao层StudentDao类

package com.example.stu.kudestu.stu.dao;import com.example.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,Integer>两个参数实体类和主键类型 Student findStuById(Integer id); @Query(name='findStuByName',nativeQuery = true,value = 'select * from student where name=:name ') List<Student> findStuByName(@Param('name') String name);}

3.编写service层类StudentService，面象接口

import com.example.stu.kudestu.stu.entity.Student;import org.springframework.data.domain.Page;import java.util.List;public interface StudentService { Student save(Student student);//添加学生 Student update(Student student);//修改 void delete(Integer id);//通过id删除学生 Student findStuById(Integer id);//通过ID查找学生，接口中没有此方法，在StudentDao接口创建 List<Student> findStuByName(String name);//通过学生姓名查找，在StudentDao接口创建 /** * 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);}

在service对接口实现

import org.springframework.stereotype.Service;import java.util.List;@Servicepublic class StudentServiceimpl implements StudentService { @Autowired//用于类中的属性注入 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); }}

4.编写Controller层StudentController类

package com.example.stu.kudestu.stu.controller;import com.example.stu.kudestu.stu.dao.StudentDao;import com.example.stu.kudestu.stu.entity.Student;import com.example.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 /*应用在Controller层的类上面@RequestMapping('/s')public class StudentController { @Autowired//依赖注入 private StudentService studentService; /** * 添加学生 * @param student 要添加学生对象 * @return */ @PostMapping('/add') /*@PostMapping 映射一个POST请求 Spring MVC新特性 提供了对Restful风格的支持@GetMapping，处理get请求 @PostMapping，处理post请求 @PutMapping，处理put请求 @DeleteMapping，处理delete请求*/ public Student save(Student student){ return studentService.save(student); } /** * 修改学生 * @param student */ @PostMapping('/update') public Student update(Student student){ return studentService.save(student); } /** * 删除学生 * @param id 要删除学生id * @return */ @GetMapping('/del/{id}') public String del(@PathVariable int id){ studentService.delete(id); return 'yes'; } @GetMapping('/findByName/{name}') public List<Student> findByName(@PathVariable String name){ return studentService.findStuByName(name); } @GetMapping('/query') public Page<Student> findByPage(Integer page , HttpServletResponse response){ response.setHeader('Access-Control-Allow-Origin','*'); //解决跨域请求 if(page==null||page<=0){ page=0; }else{ page-=1; } return studentService.findAll(page,5); }}

@RestController

应用在Controller层的类上面，@RestController注解相当于@ResponseBody ＋ @Controller合在一起的作用，同时返回的数据为json数据

使用@Controller 注解，在对应的方法上，视图解析器可以解析return 的jsp,html页面，并且跳转到相应页面若返回json等内容到页面，则需要加@ResponseBody注解

@PostMapping(value = '/add')等价于@RequestMapping(value = '/add',method = RequestMethod.POST)

5.利用HBuilder进行前端编写

Jquery.js内容到https://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js复制即可

主页面：index.html

<!DOCTYPE html><html> <head> <meta charset='utf-8'> <title></title> <script src='https://www.haobala.com/bcjs/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=’’>编辑</a>&nbsp;<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='https://www.haobala.com/bcjs/add.html' rel='external nofollow' >添加学生</a><div id='show'> </div><a href='javascript:upPage();' rel='external nofollow' >上一页</a>&nbsp;&nbsp;<a href='javascript:downPage();' rel='external nofollow' >下一页</a> </body></html>

页面效果

添加学生的页面信息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>

页面效果

’

如何利用分页

直接调用Dao接口的父类JPA接口的分页方法

在Service接口层定义：

/** * 分页查询所有数据 * @param page * @param pageSize * @return */ Page<Student> findAll(int page,int pageSize);

Service实现：

public Page<Student> findAll(int page,int pageSize) { Pageable pageable= PageRequest.of(page,pageSize); return studentDao.findAll(pageable); }

Controller层：

@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); }

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持好吧啦网。