本文介绍了同时使用POST和GET在AsyncTask的http请求的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我开发一个应用程序，这个过程从服务器获取数据
I am developing an application where the process to get data from server is
第1步：使用HTTP POST特定头内容给url post请求
第2步：作为回报，我会得到一个链接，我已经构建成一个完整的URL的一部分
Step 2: In return, i will get part of a link, which i have to construct into a full URL
科学技术审查小组3：现在，通过使用这个网址HTTP GET方法来获取数据。
Strp 3: Now, pass this URL using Http GET method to obtain the data.
现在我想实现这一点使用以下code，
Now i am trying to achieve this using following code,
@Override
protected String doInBackground(String... params)
{
try
{
/** Performing POST method to url to obtain link for data**/
HttpClient httpClient = HttpClientConstant.getThreadSafeClient();
HttpPost httpPost = new HttpPost(CHANNEL_LANGUAGE_SENTIMENT_URL);
httpPost.setEntity(new ByteArrayEntity(POST_URL_VALUES.toString().getBytes("UTF8")));
HttpResponse response = httpClient.execute(httpPost);
if(response!=null)
{
OBTAIN_URL_LINK = convertJsonToString(response.getEntity().getContent()).toString();
/** getting the link in OBTAIN_URL_LINK**/
System.out.println("Response: " + OBTAIN_URL_LINK);
try
{
/** Constructing the URL**/
JSONObject mainStringJSON = new JSONObject(OBTAIN_URL_LINK);
REFINED_URL_LINK = mainStringJSON.getString("poll_url");
REQUIRED_URL_LINK = PREDEFINED_URL_LINK + REFINED_URL_LINK;
System.out.println("URL to USE: " + REQUIRED_URL_LINK);
/** Performing GET method to obtain the Data**/
HttpClient channelHttpClient = HttpClientConstant.getThreadSafeClient();
HttpGet channelHttpGet = new HttpGet(REQUIRED_URL_LINK);
HttpResponse channelHttpResponse = channelHttpClient.execute(channelHttpGet);
/** Reading the JSON response and stroing in string**/
BufferedReader channelHttpReader = new BufferedReader(new InputStreamReader(channelHttpResponse.getEntity().getContent(), "UTF-8") );
CHANNEL_LANGUAGE_RESPONSE_JSON = channelHttpReader.readLine();
System.out.println(CHANNEL_LANGUAGE_RESPONSE_JSON);
if(CHANNEL_LANGUAGE_RESPONSE_JSON != null)
{
try
{
JSONObject mainJson = new JSONObject(CHANNEL_LANGUAGE_RESPONSE_JSON);
JSONObject dataJson = mainJson.getJSONObject("data");
//JSONObject dataJson = new JSONObject().getJSONObject("data");
/** Values for Channel Graphs**/
JSONObject channelJson = dataJson.getJSONObject("category");
int twitterValues = channelJson.getInt("twitter");
当我debugg的应用程序，它做工精细，它显示的数据。但是当我运行它的崩溃和给我这个应用，
When i debugg the application, it working fine and it shows the data. But when i run the application it's crashing and giving me this,
10-07 09:03:10.517: I/System.out(1330): org.json.JSONException: No value for data
10-07 09:03:10.517: I/System.out(1330): at org.json.JSONObject.get(JSONObject.java:354)
10-07 09:03:10.517: I/System.out(1330): at org.json.JSONObject.getJSONObject(JSONObject.java:569)
10-07 09:03:10.557: I/System.out(1330): at m_brain.m_adaptive.m_DetailActivity.ChannelsAndLanguageFilterFragment$GetChannelAndLanguageData.doInBackground(ChannelsAndLanguageFilterFragment.java:164)
10-07 09:03:10.597: I/System.out(1330): at m_brain.m_adaptive.m_DetailActivity.ChannelsAndLanguageFilterFragment$GetChannelAndLanguageData.doInBackground(ChannelsAndLanguageFilterFragment.java:1)
10-07 09:03:10.597: I/System.out(1330): at android.os.AsyncTask$2.call(AsyncTask.java:287)
10-07 09:03:10.637: I/System.out(1330): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
10-07 09:03:10.637: I/System.out(1330): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
10-07 09:03:10.637: I/System.out(1330): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
10-07 09:03:10.669: I/System.out(1330): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
10-07 09:03:10.708: I/System.out(1330): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
10-07 09:03:10.747: I/System.out(1330): at java.lang.Thread.run(Thread.java:856)
10-07 09:03:10.917: I/Choreographer(1330): Skipped 35 frames! The application may be doing too much work on its main thread.
10-07 09:03:11.047: D/AndroidRuntime(1330): Shutting down VM
10-07 09:03:11.047: W/dalvikvm(1330): threadid=1: thread exiting with uncaught exception (group=0x40a13300)
10-07 09:03:11.077: E/AndroidRuntime(1330): FATAL EXCEPTION: main
10-07 09:03:11.077: E/AndroidRuntime(1330): java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
10-07 09:03:11.077: E/AndroidRuntime(1330): at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:251)
10-07 09:03:11.077: E/AndroidRuntime(1330): at java.util.ArrayList.get(ArrayList.java:304)
10-07 09:03:11.077: E/AndroidRuntime(1330): at m_brain.m_adaptive.m_DetailActivity.ChannelsAndLanguageFilterFragment.generatePieDataChannels(ChannelsAndLanguageFilterFragment.java:311)
10-07 09:03:11.077: E/AndroidRuntime(1330): at m_brain.m_adaptive.m_DetailActivity.ChannelsAndLanguageFilterFragment.access$11(ChannelsAndLanguageFilterFragment.java:304)
10-07 09:03:11.077: E/AndroidRuntime(1330): at m_brain.m_adaptive.m_DetailActivity.ChannelsAndLanguageFilterFragment$GetChannelAndLanguageData.onPostExecute(ChannelsAndLanguageFilterFragment.java:270)
10-07 09:03:11.077: E/AndroidRuntime(1330): at m_brain.m_adaptive.m_DetailActivity.ChannelsAndLanguageFilterFragment$GetChannelAndLanguageData.onPostExecute(ChannelsAndLanguageFilterFragment.java:1)
10-07 09:03:11.077: E/AndroidRuntime(1330): at android.os.AsyncTask.finish(AsyncTask.java:631)
10-07 09:03:11.077: E/AndroidRuntime(1330): at android.os.AsyncTask.access$600(AsyncTask.java:177)
10-07 09:03:11.077: E/AndroidRuntime(1330): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
10-07 09:03:11.077: E/AndroidRuntime(1330): at android.os.Handler.dispatchMessage(Handler.java:99)
10-07 09:03:11.077: E/AndroidRuntime(1330): at android.os.Looper.loop(Looper.java:137)
10-07 09:03:11.077: E/AndroidRuntime(1330): at android.app.ActivityThread.main(ActivityThread.java:4745)
10-07 09:03:11.077: E/AndroidRuntime(1330): at java.lang.reflect.Method.invokeNative(Native Method)
10-07 09:03:11.077: E/AndroidRuntime(1330): at java.lang.reflect.Method.invoke(Method.java:511)
10-07 09:03:11.077: E/AndroidRuntime(1330): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
10-07 09:03:11.077: E/AndroidRuntime(1330): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
10-07 09:03:11.077: E/AndroidRuntime(1330): at dalvik.system.NativeStart.main(Native Method)
我在一个片段这样做的，图中这是在一个ListView中显示的数据。我是初学者在这一点，所以请指导我，如果我在一个错误的方式做这件事还是需要不同的方法。而且我不能够理解，如果这是因为HTTP请求或其他任何hapening。该生产线就显示了在尝试方法终点。
I am doing this in a Fragment and displaying Data in Graphs which are in a ListView. I am beginner in this, so please guide me if i am doing it in a wrong way or need a different approach. Moreover i am not able to understand if this is hapening because of the Http request or anything else. The line it shows point at end of the try method.
推荐答案
您可以使用这个类与此处理：
You can use this class to handle with this:
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
public class ServiceHandler
{
private JSONObject response = null;
public final static int GET = 1;
public final static int POST = 2;
public JSONObject makeServiceCall( String url, int method )
{
return this.makeServiceCall( url, method, null );
}
public JSONObject makeServiceCall( String url, int method, List<NameValuePair> params )
{
try
{
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpEntity httpEntity = null;
HttpResponse httpResponse = null;
if( method == POST )
{
HttpPost httpPost = new HttpPost( url );
if( params != null )
{
httpPost.setEntity( new UrlEncodedFormEntity( params, "UTF-8" ) );
}
httpResponse = httpClient.execute( httpPost );
}else if( method == GET )
{
if( params != null )
{
String paramString = URLEncodedUtils.format( params, "UTF-8" );
url += "?" + paramString;
}
HttpGet httpGet = new HttpGet( url );
//Envia a URL e pega a resposta.
httpResponse = httpClient.execute( httpGet );
}
httpClient = null;
httpEntity = httpResponse.getEntity();
httpResponse = null;
String JSONString = EntityUtils.toString( httpEntity );
Log.e( "JSON", JSONString );
try
{
response = new JSONObject( JSONString );
}catch( JSONException e ) { }
httpEntity = null;
}catch( UnsupportedEncodingException e )
{
e.printStackTrace();
}catch( ClientProtocolException e )
{
e.printStackTrace();
}catch( IOException e )
{
e.printStackTrace();
}
return response;
}
}
使用方法：
ServiceHandler serviceHandler = new ServiceHandler();
JSONObject jsonObj = serviceHandler.makeServiceCall( URL, ServiceHandler.POST OR ServiceHandler.GET, PARAMS );
这篇关于同时使用POST和GET在AsyncTask的http请求的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！