java - 为什么我的 Spring Boot POST 输出 "Whitelabel Error Page"？

Question

所以我试图发布某种“登录”窗口，用户必须在其中写下他们的全名才能登录。但我却得到了一个“Whitelabel Error Page”。您可以在下面找到我的代码。非常感谢您的帮助

首先是我的“用户”类(“vorname”= 名字和“nachname”= 姓氏):

package POST;

public class User {
    private String vorname;
    private String nachname;

    public User(String vorname, String nachname) {
        this.vorname = vorname;
        this.nachname = nachname;
    }

    public String getVorname() {
        return vorname;
    }

    public void setVorname(String vorname) {
        this.vorname = vorname;
    }

    public String getNachname() {
        return nachname;
    }

    public void setNachname(String nachname) {
        this.nachname = nachname;
    }
}

这是我的“UserData”类:

package POST;

import java.util.List;

public class UserData {

    private List<User> blogs;

    public User createBlog(String vorname, String nachname) {
        User newBlog = new User(vorname, nachname);
        blogs.add(newBlog);
        return newBlog;
    }

    private static UserData instance = null;
    public static UserData getInstance(){
        if(instance == null){
            instance = new UserData();
        }
        return instance;
    }
}

我的“UserAPI”类(“vorname”= 名字和“nachname”= 姓氏):

package POST;

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

import java.util.Map;

public class UserAPI {
    UserData userData = UserData.getInstance();

    @PostMapping(value = "/createUser", consumes = "application/json", produces = "application/json")
    public User createUser(@RequestBody Map<String, String> user) {
        String vorname = user.get("vorname");
        String nachname = user.get("nachname");
        return userData.createBlog(vorname, nachname);
    }
}

和我的“POSTApplication”类:

package POST;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class POSTApplication {
    public static void main(String[] args) {

        SpringApplication.run(POSTApplication.class, args);
    }
}

这是我本地主机上的输出:

Whitelabel Error Page This application has no explicit mapping for /error, so you are seeing this as a fallback. Tue Dec 24 15:30:49 CET 2019 There was an unexpected error (type=Not Found, status=404). No message available

感谢您的帮助。

Answer 1

404 Http 状态代码 表示您尝试访问的资源未在服务器中找到。

所以，我认为您忘记在 UserAPI 类的顶部添加 @RestController 注释，这就是找不到资源的原因。

试试这个:

@RestController
public class UserAPI {
UserData userData = UserData.getInstance();

@PostMapping(value = "/createUser", consumes = "application/json", produces = "application/json")
public User createUser(@RequestBody Map<String, String> user) {
    String vorname = user.get("vorname");
    String nachname = user.get("nachname");
    return userData.createBlog(vorname, nachname);
 }
}