如何使用Jersey客户端消费Facebook JSON

Question

我的代码不起作用:

package com.foo.json;

import javax.xml.bind.annotation.XmlRootElement;

import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.WebResource;

@XmlRootElement
public class Me {

    public String id;
    public String name;

    public static void main(String[] args) {
        Client client = Client.create();
        WebResource web_resource = client.resource("https://graph.facebook.com/me?fields=id,name&access_token=deleted");
        Me response = web_resource.get(Me.class);
        System.out.println(response);
    }

}

错误是:

Mar 28, 2012 11:56:43 AM com.sun.jersey.api.client.ClientResponse getEntity
SEVERE: A message body reader for Java class com.foo.json.Me, and Java type class com.foo.json.Me, and MIME media type text/javascript; charset=UTF-8 was not found
Mar 28, 2012 11:56:43 AM com.sun.jersey.api.client.ClientResponse getEntity
SEVERE: The registered message body readers compatible with the MIME media type are:
*/* ->
  com.sun.jersey.core.impl.provider.entity.FormProvider
  com.sun.jersey.core.impl.provider.entity.StringProvider
  com.sun.jersey.core.impl.provider.entity.ByteArrayProvider
  com.sun.jersey.core.impl.provider.entity.FileProvider
  com.sun.jersey.core.impl.provider.entity.InputStreamProvider
  com.sun.jersey.core.impl.provider.entity.DataSourceProvider
  com.sun.jersey.core.impl.provider.entity.XMLJAXBElementProvider$General
  com.sun.jersey.core.impl.provider.entity.ReaderProvider
  com.sun.jersey.core.impl.provider.entity.DocumentProvider
  com.sun.jersey.core.impl.provider.entity.SourceProvider$StreamSourceReader
  com.sun.jersey.core.impl.provider.entity.SourceProvider$SAXSourceReader
  com.sun.jersey.core.impl.provider.entity.SourceProvider$DOMSourceReader
  com.sun.jersey.json.impl.provider.entity.JSONJAXBElementProvider$General
  com.sun.jersey.json.impl.provider.entity.JSONArrayProvider$General
  com.sun.jersey.json.impl.provider.entity.JSONObjectProvider$General
  com.sun.jersey.core.impl.provider.entity.XMLRootElementProvider$General
  com.sun.jersey.core.impl.provider.entity.XMLListElementProvider$General
  com.sun.jersey.core.impl.provider.entity.XMLRootObjectProvider$General
  com.sun.jersey.core.impl.provider.entity.EntityHolderReader
  com.sun.jersey.json.impl.provider.entity.JSONRootElementProvider$General
  com.sun.jersey.json.impl.provider.entity.JSONListElementProvider$General
  com.sun.jersey.json.impl.provider.entity.JacksonProviderProxy

Exception in thread "main" com.sun.jersey.api.client.ClientHandlerException: A message body reader for Java class com.foo.json.Me, and Java type class com.foo.json.Me, and MIME media type text/javascript; charset=UTF-8 was not found
    at com.sun.jersey.api.client.ClientResponse.getEntity(ClientResponse.java:550)
    at com.sun.jersey.api.client.ClientResponse.getEntity(ClientResponse.java:506)
    at com.sun.jersey.api.client.WebResource.handle(WebResource.java:684)
    at com.sun.jersey.api.client.WebResource.get(WebResource.java:191)
    at com.foo.json.Me.main(Me.java:18)

卷曲URL的响应是:

$ curl --head https://graph.facebook.com/me?fields=id,name\&access_token=deleted
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Cache-Control: private, no-cache, no-store, must-revalidate
Content-Type: text/javascript; charset=UTF-8
Expires: Sat, 01 Jan 2000 00:00:00 GMT
Pragma: no-cache
X-FB-Rev: 532491
X-FB-Debug: EGBmGLM1xfMiWi8KILCkQaG6FTn+WnRufgVY7FXDxnQ=
X-Cnection: close
Content-Length: 0
Date: Wed, 28 Mar 2012 18:58:53 GMT

内容是:

$curl --head https://graph.facebook.com/me?fields=id,name\&access_token=deleted
{"id":"100001234567890","name":"My Name"}

我究竟做错了什么？我确实想使用Jersey Client库,而不想切换到另一个库.谢谢!

Answer 1

您只需要提及对application/json的响应的Accept标头,因为它将以json的形式出现.如果没有它,它将被视为text/javascript响应(检查curl响应的标题),它会给你ClientHandlerException.

运行代码:

TestClient.java

public class TestClient {

    public static void main(String[] args) {

        Client client = Client.create();
        WebResource web_resource = client.resource("https://graph.facebook.com/me?fields=id,name&access_token=deleted");
        MyBean response=web_resource.accept(MediaType.APPLICATION_JSON).get(MyBean.class);
        System.out.println(response.getId());
    }

}

MyBean.java

@XmlRootElement
public class MyBean{

    String id;
    String name;

    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}