Java的Android的OutputStreamWriter IOException異常

我有一個代碼發送請求給PHP頁面，它工作得很好，但突然（我不記得任何更改），它停止工作無論在模擬器和真實設備Java的Android的OutputStreamWriter IOException異常

URL url = new URL(this.site); 
      URLConnection conn = url.openConnection(); 

      if (!(conn instanceof HttpURLConnection)) { 
       Log.e(TAG, "connection is not HttpURLConnection"); 
       throw new IOException("Not an HTTP connection"); 

      } 

      try{ 
       Log.e(TAG, "Trying"); 
       HttpURLConnection httpConn = (HttpURLConnection) conn; 
       Log.e(TAG, "Created connection"); 
       httpConn.setAllowUserInteraction(false); 
       httpConn.setInstanceFollowRedirects(true); 
       httpConn.setRequestMethod("POST"); 
       Log.e(TAG, "connecting"); 
       httpConn.connect(); 
       Log.e(TAG, "connected"); 

       OutputStreamWriter wr = new OutputStreamWriter(httpConn.getOutputStream()); 
       Log.e(TAG, "created outputstream");

這裏是堆棧跟蹤：

 12-25 00:32:14.024: W/System.err(885): java.net.ProtocolException: Does not support output 
    12-25 00:32:14.090: W/System.err(885):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:575) 
    12-25 00:32:14.090: W/System.err(885):  at com.*****.StringAsyncRetriever.OpenHttpConnection(StringAsyncRetriever.java:122) 
    12-25 00:32:14.090: W/System.err(885):  at com.******.StringAsyncRetriever.getData(StringAsyncRetriever.java:66) 
    12-25 00:32:14.094: W/System.err(885):  at com.******.StringAsyncRetriever.doInBackground(StringAsyncRetriever.java:38) 
    12-25 00:32:14.094: W/System.err(885):  at com.******.StringAsyncRetriever.doInBackground(StringAsyncRetriever.java:1) 
    12-25 00:32:14.094: W/System.err(885):  at android.os.AsyncTask$2.call(AsyncTask.java:185) 
    12-25 00:32:14.094: W/System.err(885):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306) 
    12-25 00:32:14.094: W/System.err(885):  at java.util.concurrent.FutureTask.run(FutureTask.java:138) 
    12-25 00:32:14.094: W/System.err(885):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088) 
    12-25 00:32:14.094: W/System.err(885):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581) 
    12-25 00:32:14.094: W/System.err(885):  at java.lang.Thread.run(Thread.java:1019)

來源

2012-12-24 Romans

什麼是IOException？信息？堆棧跟蹤？ – EJP

而例外是...？ –

發佈您的stacktrace ... – PermGenError

查看源代碼，當doOutput未設置爲true該異常被拋出：

（來源：http://www.java2s.com/Open-Source/Android/android-core/platform-libcore/org/apache/harmony/luni/internal/net/www/protocol/http/HttpURLConnectionImpl.java.htm）

public OutputStream getOutputStream() throws IOException { 
    if (!doOutput) { 
     throw new ProtocolException("Does not support output"); 
    }

的HttpURLConnectionImpl類是從Java的HttpUrlConnection延伸URLConnection類擴展。看着你找到Javadoc中：

保護布爾則將DoOutput

此變量由setDoOutput 方法設置。它的值由getDoOutput方法返回。一個URL 連接可用於輸入和/或輸出。將doOutput 標誌設置爲true表示應用程序打算將數據寫入到的URL連接。

此字段的默認值爲false。

所以，你需要做的：

httpConn.setDoOutput(true);

在你的代碼。

來源

2012-12-24 23:09:08

感謝您的答案，節省了我很多時間的疑惑。我看到這隻發生在Andoird 2.x和3.x仿真器上。它很奇怪。 – Hong

Java的Android的OutputStreamWriter IOException異常

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