11_springboot JPA crud

1.在StudentController下添加增删改查

@Controller
public class StudentController {
    @Autowired
    StudentDAO studentDAO;

    @RequestMapping("/listStudent")
    public String listStudent(Model m, @RequestParam(value = "start", defaultValue = "0") int start,
                              @RequestParam(value = "size", defaultValue = "5") int size)throws Exception{
        start = start<0?0:start;

        Sort sort = Sort.by(Sort.Direction.DESC, "stuId");
        Pageable pageable = PageRequest.of(start, size, sort);
        Page<Student> page = studentDAO.findAll(pageable);

        m.addAttribute("page", page);
        return "listStudent";
    }

    @RequestMapping("/addStudent")
    public String addStudent(Student s) throws Exception{
        studentDAO.save(s);
        return "redirect:listStudent";
    }

    @RequestMapping("/deleteStudent")
    public String deleteStudent(Student s) throws Exception {
        studentDAO.delete(s);
        return "redirect:listStudent";
    }
    @RequestMapping("/updateStudent")
    public String updateStudent(Student s) throws Exception {
        studentDAO.save(s);
        return "redirect:listStudent";
    }

    @RequestMapping("/editStudent")
    public String editStudent(int stuId,Model m) throws Exception {
        Student s= studentDAO.getOne(stuId);
        m.addAttribute("s", s);
        return "editStudent";
    }
}

2.listStudent.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

<div align="center">

</div>

<div style="width:500px;margin:20px auto;text-align: center">
    <table align='center' border='1' cellspacing='0'>
        <tr>
            <td>stuId</td>
            <td>name</td>
            <td>sex</td>
            <td>编辑</td>
            <td>删除</td>
        </tr>
        <c:forEach items="${page.content}" var="s" varStatus="abc">
            <tr>
                <td>${s.stuId}</td>
                <td>${s.name}</td>
                <td>${s.sex}</td>
                <td><a href="editStudent?stuId=${s.stuId}">编辑</a></td>
                <td><a href="deleteStudent?stuId=${s.stuId}">删除</a></td>
            </tr>
        </c:forEach>

    </table>
    <br>
    <div>
        <a href="?start=0">[首  页]</a>
        <a href="?start=${page.number-1}">[上一页]</a>
        <a href="?start=${page.number+1}">[下一页]</a>
        <a href="?start=${page.totalPages-1}">[末  页]</a>
    </div>
    <br>
    <form action="addStudent" method="post">

        name: <input name="name"> <br>
        sex:  <input name="sex"><br>
        <button type="submit">提交</button>

    </form>
</div>

3.editStudent.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8" isELIgnored="false"%>

<div style="margin:0px auto; width:500px">

    <form action="/updateStudent" method="post">

        name: <input name="name" value="${s.name}"> <br>
        sex:  <input name="sex" value="${s.sex}"><br>

        <input name="stuId" type="hidden" value="${s.stuId}">
        <button type="submit">提交</button>

    </form>
</div>

---

问题：

1.Spring-Data-Jpa的Sort排序时遇到的问题 has private access in 'org.springframework.data.domain.Sort',

springboot2.2.1（含）以上的版本Sort已经不能再实例化了，构造方法已经是私有的了！我们可以改用Sort.by获得Sort对象

https://blog.csdn.net/qq_35953966/article/details/104061854

2.Pageable pageable = new PageRequest(start, size, sort) 不能使用了。改成如下

Pageable pageable = PageRequest.of(start, size, sort);

https://blog.csdn.net/weixin_44900565/article/details/105614972