如何解决415不支持的媒体类型错误？

Question

I have angular 5 which try to send PUT request to a rest service in java application:

The Angular call:

    ...
    import 'rxjs/add/operator/toPromise';

    const httpOptions = {
        headers: new HttpHeaders({ 'Accept': 'application/json', 'Content-Type': 'application/json' })
    };

    @Injectable()
    export class TripService {

...

    saveTrip(trip: Trip): Observable<any> {
    return this.http.put(`${this.baseUrl}/Trip`, JSON.stringify(trip), httpOptions);
  }

The server (java) service:

@PUT
@Consumes("application/json")
public Response updateTrip(Trip trip) {
    tripDao.updateTrip(trip);
    return Response.ok().entity("trip updated successfully").build();
}

The entity!:

@Entity
@Table(name = "trip")
@XmlRootElement
public class Trip implements java.io.Serializable {

    private static final long serialVersionUID = 1L;

    @XmlElement(name = "id")
    private Integer id;
    @XmlElement(name = "user")
    private User user;
    @XmlElement(name = "start_date")
    private Date startDate;
    ...

Request header:

Accept: application/json
Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9,he;q=0.8
Authorization: Bearer fake-jwt-token
Connection: keep-alive
Content-Length: 538
Content-Type: application/json
Host: localhost:8080
Origin: http://localhost:4200
Referer: http://localhost:4200/manager/company
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36 

The error:

Request URL: http://localhost:8080/... /rest/Trip
Request Method: PUT
Status Code: 415 Unsupported Media Type
Remote Address: [::1]:8080
Referrer Policy: no-referrer-when-downgrade

I need help with the JSON to Java conversion ? I have this jar for example: javax.ws.rs-api-2.0.1

I added the jackson jars which included currently in the project:

Answer 1

Your client is requesting application/json in its Accept header, but the server does not produce it. Add the Produces annotation that declares that the content type is supported.

@PUT
@Consumes("application/json")
@Produces("application/json")
public Response updateTrip(Trip trip) {

Beside this, your server is not responding with JSON , which is a different problem altogether. You probably want to annotate the method with:

@Consumes("text/plain") 

The most likely fix you need is to make your client send Accept: */* , or Accept: text/plain

Answer 2

Use Jackson

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.9.5</version>
    </dependency>

Unless you have any specific case, it can convert your XML response to JSON without any additional code.