[java] Getting java.net.SocketTimeoutException: Connection timed out in android

I'm relatively new to android development. I'm developing an android application where I'm sending requests to the web server and parsing JSON objects. Frequently I'm getting java.net.SocketTimeoutException: Connection timed out exception while communicating with the server. Some times it will work perfectly without any problem. I know this same question has been asked in SO many times. But still, I didn't get any satisfying solution to this problem. I'm posting my logcat and app-server communication code below.

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:

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 

Can anyone help me out to find out a solution for this? Thanks in Advance....

I was facing this problem and the solution was to restart my modem (router). I could get connection for my app to internet after that.

I think the library I am using is not managing connections properly because it happeend just few times.

Set This in OkHttpClient.Builder() Object

val httpClient = OkHttpClient.Builder()
        httpClient.connectTimeout(5, TimeUnit.MINUTES) // connect timeout
            .writeTimeout(5, TimeUnit.MINUTES) // write timeout
            .readTimeout(5, TimeUnit.MINUTES) // read timeout

I'm aware this question is a bit old. But since I stumbled on this while doing research, I thought a little addition might be helpful.

As stated the error cannot be solved by the client, since it is a network related issue. However, what you can do is retry connecting a few times. This may work as a workaround until the real issue is fixed.

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                
    }
}

Maybe this helps someone.

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();
        }
    }
}

I got this same error as I mistakenly changed the order of the statements

OkHttpClient okHttpClient = new OkHttpClient().newBuilder() .connectTimeout(20, TimeUnit.SECONDS).readTimeout(20,TimeUnit.SECONDS).writeTimeout(20, TimeUnit.SECONDS) .build();

After changing the order of writeTimeout and readTimeout, the error resolved. The final code I used is given below:

OkHttpClient okHttpClient = new OkHttpClient.Builder().connectTimeout(60, TimeUnit.SECONDS)
                    .writeTimeout(60, TimeUnit.SECONDS)
                    .readTimeout(60, TimeUnit.SECONDS)
                    .build();

If you are testing the server in localhost your Android device must be connected to the same local network. Then the Server URL used by your APP must include your computer IP Address and not the "localhost" mask.

I faced the same problem when connecting to EC2, the issue was with Security Group, I solved by adding the allowed IPs at port 5432

If you are using Kotlin + Retrofit + Coroutines then just use try and catch for network operations like,

viewModelScope.launch(Dispatchers.IO) {
        try {
            val userListResponseModel = apiEndPointsInterface.usersList()
            returnusersList(userListResponseModel)
        } catch (e: Exception) {
            e.printStackTrace()
        }
    }

Where, Exception is type of kotlin and not of java.lang

This will handle every exception like,

1. HttpException
2. SocketTimeoutException
3. FATAL EXCEPTION: DefaultDispatcher etc

Here is my usersList() function

@GET(AppConstants.APIEndPoints.HOME_CONTENT)
suspend fun usersList(): UserListResponseModel

Note: Your RetrofitClient Classs must have this as client

OkHttpClient.Builder()
            .connectTimeout(10, TimeUnit.SECONDS)
            .readTimeout(10, TimeUnit.SECONDS)
            .writeTimeout(10, TimeUnit.SECONDS)