Question

我的Android代码一直发送数据，它似乎一直有效，直到抛出完全意外的IOException，冻结所有内容。我不明白为什么我可以毫无问题地发送几个帖子请求，直到出现异常，几乎是随机的。这是我的代码：

public class HttpsClient {

private final static String TAG = "HttpsClient";

private final static String TOKEN_HEADER_KEY = "Token";

private final String urlString;

private SSLContext sslContext;

// application-specific HTTP header
private String TokenHeaderValue = null;



public HttpsClient(String host, String path) {
    // this.sslContext will be init'ed in open()
    this.urlString = "https://" + host + ":443/" + path;
}


public boolean open() {
    try {
        this.sslContext = SSLContext.getInstance("TLS");
        this.sslContext.init(null, null, new java.security.SecureRandom());
        return true;
    } catch (NoSuchAlgorithmException e) {
        Logger.e(TAG, "NoSuchAlgorithmException:");
    } catch (KeyManagementException e) {
        Logger.e(TAG, "KeyManagementException:");
    }

    return false;
}


public byte[] send(byte[] req) {

    Logger.d(TAG, "sending " + Utils.byteArrayToString(req) + " to " + this.urlString);

    URL url;
    try {
        url = new URL(this.urlString);
    } catch (MalformedURLException e) {
        Logger.e(TAG, "MalformedURLException:");
        return null;
    }
    HttpsURLConnection connection;
    try {
        connection = (HttpsURLConnection) url.openConnection();
    } catch (IOException e) {
        Logger.e(TAG, "send IOException 1 " + ((null == e.getMessage()) ? e.getMessage() : ""));
        e.printStackTrace();
        return null;
    }

    connection.setDoInput(true);
    connection.setDoOutput(true);
    connection.setRequestProperty("Connection", "close");
    try {
        connection.setRequestMethod("POST");

    } catch (ProtocolException ignored) { }
    connection.setSSLSocketFactory(this.sslContext.getSocketFactory());
    connection.setReadTimeout(3000);



    if ( this.TokenHeaderValue != null )
        connection.setRequestProperty(TOKEN_HEADER_KEY, this.TokenHeaderValue);



    {
        final Map<String, List<String>> requestProps = connection.getRequestProperties();
        Logger.d(TAG, requestProps.size() + " Request header(s):");
        for (Map.Entry<String, List<String>> entry : requestProps.entrySet())
            for (String value : entry.getValue())
                Logger.d(TAG, " " + entry.getKey() + ": <" + value + ">");
    }

    try {
        // open up the output stream of the connection 
        DataOutputStream output = new DataOutputStream(connection.getOutputStream()); 

        // write out the data 
        output.write(req, 0, req.length);
        output.flush();


        Logger.i(TAG, "Response Code: " + connection.getResponseCode());
        Logger.i(TAG, "Response Message: " + connection.getResponseMessage()); 
    } catch (SocketTimeoutException e) {
        Logger.e(TAG, "SocketTimeoutException:" + ((null == e.getMessage()) ? e.getMessage() : ""));
        return null;
    } catch (IOException e) { // FAILS HERE !!!!!!!
        Logger.e(TAG, "send IOException 2 " + ((null == e.getMessage()) ? e.getMessage() : ""));
        return null;
    }


    final Map<String, List<String>> responseHeaderFields = connection.getHeaderFields();
    Logger.d(TAG, responseHeaderFields.size() + " Response header(s):");
    for (Map.Entry<String, List<String>> entry : responseHeaderFields.entrySet()) {
        final String key = entry.getKey();
        if ( (null != key) && key.equals(TOKEN_HEADER_KEY) )
            this.TokenHeaderValue = entry.getValue().get(0);
        for (String value : entry.getValue())
            Logger.d(TAG, " " + key + ": <" + value + ">");
    }


    // read response
    ArrayList<Byte> response = new ArrayList<Byte>();

    try {
        DataInputStream input = new DataInputStream(connection.getInputStream()); 

        // read in each character until end-of-stream is detected
        for( int c = input.read(); c != -1; c = input.read() ) {
            response.add((byte) c);
        }
        Logger.w(TAG, "Https connection is " + connection);
        connection.disconnect();
        Logger.w(TAG, "Https connection is " + connection);
        input.close();

    } catch (IOException e) {
        Logger.e(TAG, "send IOException 3 " + ((null == e.getMessage()) ? e.getMessage() : ""));
        return null;
    }

    if ( 0 == response.size() ) {
        Logger.w(TAG, "response is null");

        return null;
    }

    // else

    byte[] result = new byte[response.size()];
    for (int i = 0; i < result.length; i++)
        result[i] = response.get(i).byteValue();

    Logger.i(TAG, "Response payload: " + Utils.byteArrayToString(result));



    return result;          
}
}

我再说一遍：代码在许多发送后发挥作用，然后崩溃导致IO异常。此外，服务器很好，我的代码有问题。

这是整个错误堆栈跟踪：

send IOException 2 

0: org.apache.harmony.xnet.provider.jsse.NativeCrypto.SSL_read_byte(Native Method)

1: org.apache.harmony.xnet.provider.jsse.OpenSSLSocketImpl$SSLInputStream.read(OpenSSLSocketImpl.java:783)

2: org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.readLine(HttpURLConnectionImpl.java:671)

3: org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.readResponseHeaders(HttpURLConnectionImpl.java:699)

4: org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getFromNetwork(HttpURLConnectionImpl.java:1088)

5: org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.retrieveResponse(HttpURLConnectionImpl.java:1041)

6: org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getResponseCode(HttpURLConnectionImpl.java:736)

7: org.apache.harmony.luni.internal.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:146)

8: com.bitstorms.gui.channels.HttpsClient.send(HttpsClient.java:117)

9: com.bitstorms.gui.apps.Application$MyRunnable.run(Application.java:81)

10: java.lang.Thread.run(Thread.java:1020)

Answer 1

可疑点是你永远不会正确释放流。例如，您创建DataOutputStream output，使用它，但永远不会关闭。尝试更改使用finally关闭流的代码：

DataOutputStream output = null;
try {
    output = new DataOutputStream(connection.getOutputStream());
    ...
} catch (...) {
    ...
} finally {
    if (output != null) {
         try {
             output.close();
         } catch (IOException ignored) {}
    }
}

同样应该使用DataInputStream input和connection本身（在某些全球finally部分中应保证关闭）。

当我尝试通过HttpsUrlConnection发送帖子时出现意外的IOException

1 个答案: