Question

我开发了一个学生管理Web应用程序，使用spring MVC，Hibernate和MYSQL数据库添加，编辑和删除学生。

添加和编辑选项正常工作，但点击删除时显示HTTP状态400。

控制器中的删除功能与编辑相同，只是在url中，而在hibernate中调用delete函数。

控制器

package com.akhil.controller;

import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.ui.ModelMap;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.mvc.annotation.ModelAndViewResolver;

import com.akhil.model.Student;
import com.akhil.service.StudentService;

@Controller
public class StudentController {
@Autowired
private StudentService studentService;

@RequestMapping("/")
public String setupForm(ModelMap model){
    Student student = new Student();
    model.addAttribute("student", student);
    model.addAttribute("studentList", studentService.getAllStudent());
    return "student";
}
@RequestMapping(value="/student.do", method=RequestMethod.POST)
public String doActions(@ModelAttribute Student student, BindingResult result, @RequestParam String action, Map<String, Object> map){
    Student studentResult = new Student();
    studentService.add(student);
    map.put("student", studentResult);
    map.put("studentList", studentService.getAllStudent());
    return "student";
}
@RequestMapping(value="/editstudent", method=RequestMethod.GET)
public String editstudent(@RequestParam("studentId") int studentID, Model model) {

    Student student = studentService.getStudent(studentID);
    model.addAttribute(student);
    return "student1";
    }
@RequestMapping(value="/updatestudent.do", method=RequestMethod.POST)
public String updatestudent(@ModelAttribute Student student, BindingResult result, @RequestParam String action, Map<String, Object> map){
    Student studentResult = new Student();
    studentService.edit(student);
    //map.put("student", studentResult);
    map.put("studentList", studentService.getAllStudent());
    return "student";
}
@RequestMapping(value="/deletestudent", method=RequestMethod.GET)
public String deletestudent(@RequestParam("studentId") int studentID, Model model) {
    Student studentResult = new Student();
    studentService.delete(studentID);
    model.addAttribute("student", studentResult);
    model.addAttribute("studentList", studentService.getAllStudent());
    return "student";
    }

}

查看

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ include file="/WEB-INF/jsp/includes.jsp"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"   "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Student Management</title>
</head>
<body>
<h1>Students Data</h1>
<form:form action="student.do" method="POST" commandName="student">
<table>
    <tr>
        <td><form:label path="studentId">Student ID:</form:label></td>
        <td><form:input path="studentId" value="${Student.studentID}" />   </td>
    </tr>
    <tr>
        <td>First name</td>
        <td><form:input path="firstname" value="${Student.firstname}"/></td>
    </tr>
    <tr>
        <td>Last name</td>
        <td><form:input path="lastname" value="${Student.lastname}" /></td>
    </tr>
    <tr>
        <td>Year Level</td>
        <td><form:input path="yearLevel" value="${Student.yearLevel}" />  </td>
    </tr>
    <tr>
        <td colspan="2">
            <input type="submit" name="action" value="Add" />
            <input type="submit" name="action" value="Edit" />
            <input type="submit" name="action" value="Delete" />
            <input type="submit" name="action" value="Search" />
        </td>
    </tr>
</table>
</form:form>
<br>
<table border="1">
<tr>
<th>ID</th>
<th>First name</th>
<th>Last name</th>
<th>Year level</th>
</tr>
<c:forEach items="${studentList}" var="student">
    <tr>
        <td>${student.studentId}</td>
        <td>${student.firstname}</td>
        <td>${student.lastname}</td>
        <td>${student.yearLevel}</td>
        <td align="center"><a href="editstudent.html? studentId=${student.studentId}">Edit</a> | <a href="deletestudent.html?studentIds=${student.studentId}">Delete</a></td>
    </tr>
</c:forEach>
</table>
</body>
</html>

Answer 1

'delete'链接发送一个名称错误的参数（'studentIdsssss'而不是'studentId'）。这会产生错误，因为@RequestParam默认为'required = true'。

顺便说一句，请注意，将“副作用”操作（例如编辑，删除）公开为POST更为习惯。但是除了这一点之外，如果仅仅是为了一个简单的演示，它可能还可以。

Spring MVC HTTP Status 400

1 个答案: