Android java.net.SocketTimeoutException：连接超时

Question

最近，我在程序中遇到以下错误：

11-18 12:30:30.259: W/System.err(21368): java.net.SocketTimeoutException: Connection timed out
11-18 12:30:30.259: W/System.err(21368):    at org.apache.harmony.luni.platform.OSNetworkSystem.connect(Native Method)
11-18 12:30:30.259: W/System.err(21368):    at dalvik.system.BlockGuard$WrappedNetworkSystem.connect(BlockGuard.java:357)
11-18 12:30:30.259: W/System.err(21368):    at org.apache.harmony.luni.net.PlainSocketImpl.connect(PlainSocketImpl.java:204)
11-18 12:30:30.259: W/System.err(21368):    at org.apache.harmony.luni.net.PlainSocketImpl.connect(PlainSocketImpl.java:437)
11-18 12:30:30.259: W/System.err(21368):    at java.net.Socket.connect(Socket.java:1002)
11-18 12:30:30.259: W/System.err(21368):    at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.<init>(HttpConnection.java:75)
11-18 12:30:30.259: W/System.err(21368):    at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.<init>(HttpConnection.java:48)
11-18 12:30:30.269: W/System.err(21368):    at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection$Address.connect(HttpConnection.java:322)
11-18 12:30:30.269: W/System.err(21368):    at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnectionPool.get(HttpConnectionPool.java:89)
11-18 12:30:30.269: W/System.err(21368):    at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getHttpConnection(HttpURLConnectionImpl.java:285)
11-18 12:30:30.269: W/System.err(21368):    at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.makeConnection(HttpURLConnectionImpl.java:267)
11-18 12:30:30.269: W/System.err(21368):    at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:205)
11-18 12:30:30.269: W/System.err(21368):    at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:614)
11-18 12:30:30.269: W/System.err(21368):    at com.example.simplevider.SimpleVideo$4.run(SimpleVideo.java:122)
11-18 12:30:30.279: W/System.err(21368):    at java.lang.Thread.run(Thread.java:1019)

产生此错误的函数如下：

    private void sendStuff() {
    Log.e("sendStuff", "======================================");
    new Thread(new Runnable() {

        @Override
        public void run() {
            final int BUFFER_SIZE = 4096;
            try {
                File uploadFile = new File(existingFileName);
                System.out.println("File to upload: " + existingFileName);
                URL url = new URL(URL);

                HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
                httpConn.setUseCaches(false);
                httpConn.setDoOutput(true);
                httpConn.setRequestMethod("POST");
                httpConn.setReadTimeout(60*1000);
                httpConn.setConnectTimeout(60 * 1000);
                // sets file name as a HTTP header
                httpConn.setRequestProperty("fileName", uploadFile.getName());
                httpConn.setRequestProperty("extra-id", uploadFile.getAbsoluteFile().toString());
                httpConn.setRequestProperty("extra-id2", uploadFile.getParent());
                httpConn.setRequestProperty("extra-id3", uploadFile.length() + "");



                OutputStream outputStream = httpConn.getOutputStream(); //<< this is the source of the error


                FileInputStream inputStream = new FileInputStream(uploadFile);

                byte[] buffer = new byte[BUFFER_SIZE];
                int bytesRead = -1;

                System.out.println("Start writing data...");

                while ((bytesRead = inputStream.read(buffer)) != -1) {
                    outputStream.write(buffer, 0, bytesRead);
                }

                System.out.println("Data was written.");
                outputStream.close();
                inputStream.close();

                // always check HTTP response code from server
                int responseCode = httpConn.getResponseCode();
                if (responseCode == HttpURLConnection.HTTP_OK) {
                    // reads server's response
                    BufferedReader reader = new BufferedReader(new InputStreamReader(httpConn.getInputStream()));
                    String response = reader.readLine();
                    System.out.println("Server's response: " + response);
                } else {
                    System.out.println("Server returned non-OK code: " + responseCode);
                }

            } catch (Exception e) {
                e.printStackTrace();
                sendStuff();
            }

        }
    }).start();

}

该功能在普通的JAVA中可以正常使用，但是当它复制到Android时会强制转换java.net.SocketTimeoutException: Connection timed out，我不知道为什么。

Answer 1

有两种可能性，

1）您是否检查并测试了连接。

2）最好不要设置任何连接超时，如果您设置了选择的最大时间，则bcos会引发错误，如果服务器在给定时间内没有响应。