获取java.net.SocketTimeoutException: Connection timed out ,怎么解决此异常?

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我对android开发比较陌生。我正在开发一个android应用程序,我正在向web服务器发送请求并解析json对象。java.net.SocketTimeoutException: Connection timed out在与服务器通信时,我经常遇到异常。有些时候它可以很好地工作,没有任何问题。我知道这个问题在很多时候都被问过。但仍然没有得到任何令人满意的解决方案来解决这个问题。我在下面发布我的logcat和应用服务器通信代码。

public JSONObject RequestWithHttpUrlConn(String _url, String param){

    HttpURLConnection con = null;
    URL url;
    String response = "";
    Scanner inStream = null;
    PrintWriter out = null;
    try {
        url = new URL(_url);
        con = (HttpURLConnection) url.openConnection();
        con.setDoOutput(true);
        con.setRequestMethod("POST");
        if(param != null){
            con.setFixedLengthStreamingMode(param.getBytes().length);
        }
        con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
        out = new PrintWriter(con.getOutputStream());
        if(param != null){
            out.print(param);
        }
        out.flush();
        out.close();
        inStream = new Scanner(con.getInputStream());

        while(inStream.hasNextLine()){
            response+=(inStream.nextLine());
        }
    } catch (MalformedURLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } finally{
        if(con != null){
            con.disconnect();
        }if(inStream != null){
            inStream.close();
        }if(out != null){
            out.flush();
            out.close();
        }
    }
}

logcat的:

03-25 10:55:32.613: W/System.err(18868): java.net.SocketTimeoutException: Connection 
timed out
03-25 10:55:32.617: W/System.err(18868):at org.apache.harmony.luni.platform.OSNetworkSystem.connect(Native Method)
03-25 10:55:32.617: W/System.err(18868):at dalvik.system.BlockGuard
$WrappedNetworkSystem.connect(BlockGuard.java:357)
03-25 10:55:32.617: W/System.err(18868):at 
org.apache.harmony.luni.net.PlainSocketImpl.connect(PlainSocketImpl.java:204)
03-25 10:55:32.617: W/System.err(18868):at 
org.apache.harmony.luni.net.PlainSocketImpl.connect(PlainSocketImpl.java:437)
03-25 10:55:32.617: W/System.err(18868):at        java.net.Socket.connect(Socket.java:1002)
03-25 10:55:32.621: W/System.err(18868):at 
org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.<init>
(HttpConnection.java:75)
03-25 10:55:32.621: W/System.err(18868): at 
org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.<init>
(HttpConnection.java:48)03-25 10:55:32.624: W/System.err(18868):at 
org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection$Address.connect
(HttpConnection.java:322)03-25 10:55:32.624: W/System.err(18868):at 
org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnectionPool.get
(HttpConnectionPool.java:89)03-25 10:55:32.628: W/System.err(18868):at 
org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getHttpCon
nection(HttpURLConnectionImpl.java:285)
03-25 10:55:32.628: W/System.err(18868):at     org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.makeConn
ection(HttpURLConnectionImpl.java:267)
03-25 10:55:32.636: W/System.err(18868):at
org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.connect
(HttpURLConnectionImpl.java:205)
03-25 10:55:32.636: W/System.err(18868):at 
org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getOutputS
tream(HttpURLConnectionImpl.java:614)
03-25 10:55:32.636: W/System.err(18868):at 
com.myapp.core.JSONRequest.RequestWithHttpUrlConn(JSONRequest.java:63)
03-25 10:55:32.636: W/System.err(18868):    at com.myapp.core.DetailPage
$AsyncRecBooks.doInBackground(AKBookDetailView.java:265)
03-25 10:55:32.640: W/System.err(18868):    at com.myapp.core.DetailPage
$AsyncRecBooks.doInBackground(AKBookDetailView.java:1)
03-25 10:55:32.640: W/System.err(18868):    at android.os.AsyncTask$2.call
(AsyncTask.java:185)
03-25 10:55:32.640: W/System.err(18868):    at java.util.concurrent.FutureTask
$Sync.innerRun(FutureTask.java:306)
03-25 10:55:32.640: W/System.err(18868):    at java.util.concurrent.FutureTask.run
(FutureTask.java:138)
03-25 10:55:32.640: W/System.err(18868):    at 
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
03-25 10:55:32.648: W/System.err(18868):    at 
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
03-25 10:55:32.648: W/System.err(18868):    at java.lang.Thread.run(Thread.java:1019)
03-25 10:55:32.652: E/JSON Parser(18868): Error parsing data org.json.JSONException:  
End of input at character 0 of 
提问于
用户回答回答于

我搜索了整个网络和阅读了很多关于连接超时异常的文档后,我明白的是,防止SocketTimeoutException超出了我们的限制......有效处理它的一种方法是定义连接超时并稍后处理它通过使用try catch块......希望这将有助于将来面临同样问题的任何人。

HttpUrlConnection conn = (HttpURLConnection) url.openConnection();
conn.setConnectTimeout(7000); //set the timeout in milliseconds
用户回答回答于

我知道这个问题有点老了。但是因为我在研究时偶然发现了这个问题,所以我认为一点补充可能会有所帮助。

如上所述,错误不能由客户解决,因为它是一个网络相关的问题。但是,您可以做的是重试连接几次。这可能会作为一种解决方法,直到真正的问题得到解决。

for (int retries = 0; retries < 3; retries++) {
    try {
        final HttpClient client = createHttpClientWithDefaultSocketFactory(null, null);
        final HttpResponse response = client.execute(get);
        final int statusCode = response.getStatusLine().getStatusCode();
        if (statusCode != 200) {
            throw new IllegalStateException("GET Request on '" + get.getURI().toString() + "' resulted in " + statusCode);
        } else {                
            return response.getEntity();
        }
    } catch (final java.net.SocketTimeoutException e) {
        // connection timed out...let's try again                
    }
}

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