java错误405:删除和放置时不允许使用方法

Question

我遵循这个spring tutorial，一切都很顺利。在此之后，我决定添加删除和修改函数。我已经实现了它们，但是当我尝试使用它们时，我得到了以下错误：

{"status":405,"error":"Method Not Allowed","message":"Request method 'POST' not supported","path":"/demo/delete"}

{"status":405,"error":"Method Not Allowed","message":"Request method 'POST' not supported","path":"/demo/modify"}

我正在执行的命令：

curl localhost:8080/demo/delete -d name=First

curl localhost:8080/demo/modify -d name=First -d email=abc@gmail.com

//if the name doesn't exist in both methods, it will return "Nonexistent user!"

以下是以下代码：

主控制器。java

package com.example.accessingdatamysql;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;

@Controller 
@RequestMapping(path="/demo") 
public class MainController {
    @Autowired 
    private UserRepository userRepository;

    @PostMapping(path="/add") 
    public @ResponseBody String addNewUser (@RequestParam String name, 
           @RequestParam String email) {

        User n = new User();
        n.setName(name);
        n.setEmail(email);
        userRepository.save(n);
        return "Saved\n";
    }

    @GetMapping(path="/all")
    public @ResponseBody Iterable<User> getAllUsers() {
        return userRepository.findAll();
    }

    /* ----------------- NEW METHODS THAT I'VE CREATED ----------------- */

    @DeleteMapping(path="/delete")
    public String delete(@RequestParam String name) throws Exception {
        if(userRepository.findByName(name).equals(null)) {
            System.out.println("Nonexistent user!\n");
        }
        userRepository.deleteByName(name);
        return "User successfully deleted!\n";
    }

    @PutMapping(path="/modify")
    public String modify(@RequestParam String name, @RequestParam String email) throws Exception {
        if(userRepository.findByName(name).equals(null)) {
            System.out.println("Nonexistent user!\n");
        }

        userRepository.deleteByName(name);
        User n = new User();
        n.setName(name);
        n.setEmail(email);
        userRepository.save(n);
        return "User successfully modified!\n";
    }
}

用户。java

package com.example.accessingdatamysql;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class User {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Integer id;

    private String name;

    private String email;

    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 String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

用户存储库。java

package com.example.accessingdatamysql;

import org.springframework.data.repository.CrudRepository;

import com.example.accessingdatamysql.User;

public interface UserRepository extends CrudRepository<User, Integer> {

    public User findByName(String name);
    public void deleteByName(String name);
}

我不知道这里发生了什么。我搜索过其他类似的问题，但都没有解决我的问题

Answer 1

在遵循@Dez的答案后，问题得到了解决，但我遇到了另一个错误：

No EntityManager with actual transaction available for current thread - cannot reliably process 'persist' call

我通过在MainController类中的DELETE和PUT方法中添加@Transactional来解决这个问题：

@DeleteMapping(path="/delete")
@Transactional //added
public void delete(@RequestParam String name) throws Exception { (...) }

@PutMapping(path="/modify")
@Transactional //added
public void modify(@RequestParam String name, @RequestParam String email) throws Exception { (...) }

并修改了异常抛出条件，该条件始终返回^{：

if(userRepository.findByName(name).equals(null)) {
     throw new Exception("Nonexistent user!");
}

到

if(userRepository.findByName(name) == null) {
     throw new Exception("Nonexistent user!");
}

Answer 2

您正在使用方法POST执行调用，而不是/demo/delete的DELETE和PUT的/demo/modify

{"status":405,"error":"Method Not Allowed","message":"Request method 'POST' not supported","path":"/demo/delete"}

{"status":405,"error":"Method Not Allowed","message":"Request method 'POST' not supported","path":"/demo/modify"}

您没有展示如何执行这些失败的调用，但是，例如，如果您正在使用GUI客户端（如Postman）来模拟调用，请检查您是否选择了正确的HTTP方法。 如果您正在终端中使用curl库，请注意方法集：

curl -X "DELETE" http://your.url/demo/delete ...

curl -X "PUT" http://your.url/demo/modify ...

Answer 3

这就是@DeleteMapping和@PutMapping的工作原理。这些注释是指向@RequestMapping的快捷方式，其中method属性相应地固定为DELETE或PUT。要允许端点使用多个HTTP方法，应明确列出它们：

@RequestMapping(path = "/modify", method = { RequestMethod.DELETE, RequestMethod.POST })
public String modify(...){
   ...
}