如何使用Google API Java客户端向Google Shortener API发布请求并解析JSON响应?
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12-10-2019 - |
题
我想使用 Google Shortener API. 。我想使用Google API Java客户端库发布请求并解析JSON响应。
接下来,我发布了我尝试过的代码:
import java.io.IOException;
import net.sf.json.JSONObject;
import com.google.api.client.googleapis.GoogleHeaders;
import com.google.api.client.googleapis.GoogleTransport;
import com.google.api.client.googleapis.json.JsonCParser;
import com.google.api.client.http.HttpRequest;
import com.google.api.client.http.HttpResponse;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.JsonHttpContent;
import com.google.api.client.util.GenericData;
public class GoogleShortener {
public static final String GOOGL_URL = "https://www.googleapis.com/urlshortener/v1/url";
public static void main(String[] args) {
// setup up the HTTP transport
HttpTransport transport = GoogleTransport.create();
// add default headers
GoogleHeaders defaultHeaders = new GoogleHeaders();
transport.defaultHeaders = defaultHeaders;
transport.defaultHeaders.put("Content-Type", "application/json");
transport.addParser(new JsonCParser());
// build the HTTP GET request and URL
GenericData data = new GenericData();
data.put("longUrl", "http://www.google.com/");
JsonHttpContent content = new JsonHttpContent();
content.data = data;
HttpRequest request = transport.buildPostRequest();
request.content = content;
request.setUrl(GOOGL_URL);
HttpResponse response;
try {
JSONObject json = request.execute().parseAs(JSONObject.class);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
当我执行上述代码时,我将获得下一个输出:
Exception in thread "main" java.lang.IllegalArgumentException: data key not found
at com.google.api.client.googleapis.json.JsonCParser.parserForResponse(JsonCParser.java:77)
at com.google.api.client.googleapis.json.JsonCParser.parse(JsonCParser.java:47)
at com.google.api.client.http.HttpResponse.parseAs(HttpResponse.java:261)
at GoogleShortener.main(GoogleShortener.java:43)
有什么想法如何正确设置JSONCPARSER?
错误路径
一开始,我没有正确设置请求内容。如@DWB所指出的那样,应设置请求内容:
GenericData data = new GenericData();
data.put("longUrl", "http://www.google.com/");
JsonHttpContent content = new JsonHttpContent();
content.data = data;
request.content = content;
如果您不正确设置内容,您将获得下一个错误
com.google.api.client.http.httpresponseexception:411在com.google.api.api.client.http.http.httprequest.execute(httprequest.java:209)
解决方案
您需要像这样将JSON内容添加到请求主体:
GenericData data = new GenericData();
data.put("longUrl", "http://www.google.com/");
JsonHttpContent content = new JsonHttpContent();
content.data = data;
request.content = content;
对于响应,请尝试使用JSONHTPPPARSER而不是JSONCPARSER。您需要创建一个子类的概括,该子类包含您要检索的每个JSON属性的字段。您可以使用Response.parseasString()查看所有可用属性。
这是一个完整的工作示例:
import com.google.api.client.googleapis.GoogleHeaders;
import com.google.api.client.googleapis.GoogleTransport;
import com.google.api.client.http.HttpRequest;
import com.google.api.client.http.HttpResponse;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.GenericJson;
import com.google.api.client.json.JsonHttpContent;
import com.google.api.client.json.JsonHttpParser;
import com.google.api.client.util.GenericData;
import com.google.api.client.util.Key;
public class Shortener {
public static final String GOOGL_URL = "https://www.googleapis.com/urlshortener/v1/url";
/**
* @param args
*/
public static void main(String[] args) throws Exception {
// setup up the HTTP transport
HttpTransport transport = GoogleTransport.create();
// add default headers
GoogleHeaders defaultHeaders = new GoogleHeaders();
transport.defaultHeaders = defaultHeaders;
transport.defaultHeaders.put("Content-Type", "application/json");
transport.addParser(new JsonHttpParser());
// build the HTTP GET request and URL
HttpRequest request = transport.buildPostRequest();
request.setUrl(GOOGL_URL);
GenericData data = new GenericData();
data.put("longUrl", "http://www.google.com/");
JsonHttpContent content = new JsonHttpContent();
content.data = data;
request.content = content;
HttpResponse response = request.execute();
Result result = response.parseAs(Result.class);
System.out.println(result.shortUrl);
}
public static class Result extends GenericJson {
@Key("id")
public String shortUrl;
}
}
其他提示
DWB给出的代码是正确的,但是它使用了Google客户端API的不弃用方法。
具有当前图书馆支持的实施如下:
import java.util.HashMap;
import java.util.Map;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.GenericUrl;
import com.google.api.client.http.HttpContent;
import com.google.api.client.http.HttpHeaders;
import com.google.api.client.http.HttpRequest;
import com.google.api.client.http.HttpResponse;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.http.json.JsonHttpContent;
import com.google.api.client.json.GenericJson;
import com.google.api.client.json.JsonObjectParser;
import com.google.api.client.json.jackson.JacksonFactory;
import com.google.api.client.util.Key;
public class ShortenUrl {
/**
* @param args
*/
public static void main(String[] args) throws Exception {
HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
HttpHeaders headers = new HttpHeaders();
JsonObjectParser parser = new JsonObjectParser(new JacksonFactory());
GenericUrl url = new GenericUrl("https://www.googleapis.com/urlshortener/v1/url");
Map<String, String> json = new HashMap<String, String>();
json.put("longUrl", "http://www.google.com/");
final HttpContent content = new JsonHttpContent(new JacksonFactory(), json);
HttpRequest request = httpTransport.createRequestFactory().buildPostRequest(url, content);
try {
HttpResponse response = request.execute();
Result result = response.parseAs(Result.class);
System.out.println(result.shortUrl);
} catch (Exception e) {
e.printStackTrace();
}
}
public static class Result extends GenericJson {
@Key("id")
public String shortUrl;
}
}
注意:您应该使用OAuth 2.0凭据使用Google API服务。
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