无法在 Spring MVC 中发送 POST 请求

Question

我使用 jersey 和 spring boot 创建了一个 API。现在，当我在请求正文中使用 Postman 发出 POST 请求时：

{
     "name":"something", "email":"something","location":"something","dateOfBirth":"something"
}

它有效。保存此数据的函数是：

@POST
@Path("/addEmployee")
    @Produces(MediaType.TEXT_PLAIN)
    public String addEmployee(@RequestBody Employee employee) {
        service.save(employee);
        return "Saved Successfully";
    }

员工模型是：

@Entity
@Table(name = "employee")
@XmlRootElement(name = "employee")
@EntityListeners(AuditingEntityListener.class)
public class Employee {
    public Employee() {
    }
    @Id
    @Column(nullable = false, name = "id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(nullable = false, name = "name")
    private String name;

    @Column(nullable = false, name = "email")
    private String email;

    @Column(nullable = false, name = "location")
    private String location;

    @Column(nullable = false, name = "DOB")
    private String dateOfBirth;

    // getters and setters

这个api是由客户端下面的函数调用的：

@RequestMapping(value = "/addEmployee", method = RequestMethod.GET)
    public ModelAndView addEmployee(ModelAndView model) {

        RestTemplate restTemplate = new RestTemplate();
        String url = "http://localhost:8080/api/addEmployee";

        EmployeeInfo employee = new EmployeeInfo();
        employee.setName("Ashish");
        employee.setEmail("anyhing");
        employee.setDateOfBirth("mybirthday");
        employee.setLocation("home");
        ResponseEntity<String> response = restTemplate.postForEntity(url, employee, String.class);

        model.setViewName("homePage");
        return model;
    }

员工信息类是：

public class EmployeeInfo {

    private String name;

    private String email;

    private String location;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getEmail() {
        return email;
    }

我得到的错误是：

  2018-09-16 15:57:13.706 ERROR 14892 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.web.client.HttpClientErrorException: 404 null] with root cause

org.springframework.web.client.HttpClientErrorException: 404 null
    at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:86) ~[spring-web-4.3.19.RELEASE.jar:4.3.19.RELEASE]
    at org.springframework.web.client.RestTemplate.handleResponse(RestTemplate.java:708) ~[spring-web-4.3.19.RELEASE.jar:4.3.19.RELEASE]
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:661) ~[spring-web-4.3.19.RELEASE.jar:4.3.19.RELEASE]
    at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:621) ~[spring-web-4.3.19.RELEASE.jar:4.3.19.RELEASE]
    at org.springframework.web.client.RestTemplate.postForEntity(RestTemplate.java:415) ~[spring-web-4.3.19.RELEASE.jar:4.3.19.RELEASE]
    at com.example.controller.Home.addEmployee(Home.java:82) ~[classes/:na]

还有一长串这样的清单。

调用它的形式是：

<form name="myform" method="post" action="addEmployee" >
        <input type="submit" value="Save">
</form>

编辑：在将客户端的方法 = RequestMethod.GET 更改为 RequestMethod.POST 时，没有任何反应，仍然出现相同的错误 我做错了什么？

Answer 1

在查看您的代码问题后，您的后端运行在 8090 端口上的客户端应用程序中，而在 api 中您调用的 addEmployee 使用的是 8080。

将此String url = "http://localhost:8080/api/addEmployee"; 更改为String url = "http://localhost:8090/api/addEmployee";，您应该会很好。

@RequestMapping(value = "/addEmployee", method = RequestMethod.GET)
    public String addEmployee(ModelAndView model) {



        RestTemplate restTemplate = new RestTemplate();
        String url = "http://localhost:8090/api/addEmployee";

        EmployeeInfo employee = new EmployeeInfo();
        employee.setName("Ashish");
        employee.setEmail("anyhing");
        employee.setDateOfBirth("mybirthday");
        employee.setLocation("home");

        System.out.println("WE HAVE REACHED HERE");
        String response = restTemplate.postForObject(url, employee, String.class);
        System.out.println(response);

        return "redirect:/home";
    }

Answer 2

404 表示请求的源不存在，可能是因为以下原因之一：

1. 没有控制器方法来处理 POST 请求，所以尝试将 which@RequestMapping(value = "/addEmployee", method = RequestMethod.GET) 更改为 @RequestMapping(value = "/addEmployee", method = RequestMethod.POST)

2. 尝试使用此注解@RestController移动此方法并使其成为restful控制器中的服务

3. 我看到您正在访问这个我认为配置不正确的 /api/addEmployee？

Answer 3

我们应该使用 RequestMethod.POST 而不是 RequestMethod.GET

@RequestMapping(value = "/addEmployee", method = RequestMethod.POST)
    public ModelAndView addEmployee(ModelAndView model) {

        RestTemplate restTemplate = new RestTemplate();
        String url = "http://localhost:8080/api/addEmployee";

        EmployeeInfo employee = new EmployeeInfo();
        employee.setName("Ashish");
        employee.setEmail("anyhing");
        employee.setDateOfBirth("mybirthday");
        employee.setLocation("home");
        ResponseEntity<String> response = restTemplate.postForEntity(url, employee, String.class);

        model.setViewName("homePage");
        return model;
    }