We Keep Coding

java.net.ConnectException: errno: 110 (Connection timed out)

I'm trying to connect client server, where I'm facing below mentioned error while opening connection:
java.net.ConnectException: errno: 110 (Connection timed out), error:
Connection timed out (local port XXXXX to address 0:0:0:0:0:0:0:0, remote
port XXXX to address XXX.XXX.XXX.XX)
Code Snippet:
URL url = new URL("http://XXX.XXX.XXX.XX:XXXX/services/ServiceEngine");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/json");
OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream());
writer.write(json);
writer.close();
BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
while ((line = br.readLine()) != null) {
jsonString.append(line);
}
br.close();
connection.disconnect();

Connection timeouts happen when the server fails to respond in a pre-determined time period and shouldn't have much to do with the logic in your code.
You can change this time period with the HttpURLConnection.setConnectTimeout() like this:
connection.setConnectTimeout(10000); //Time is set in milliseconds, so 1000 is 1 second.
Also as another user pointed out it could be that your server isn't actually up and ready to host connections.

Why doses this code sometimes throw UnknownHostException but other times throw SocketTimeoutException [duplicate]

This question already has answers here:
Networking code sometimes throws UnknownHostException
(4 answers)
Closed 3 years ago.
URL realUrl = new URL("xxx.xxxx.com");
URLConnection conn = realUrl.openConnection();
conn.setRequestProperty("accept", "*/*");
conn.setRequestProperty("connection", "Keep-Alive");
conn.setRequestProperty("user-agent",
"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
conn.setDoOutput(true);
conn.setDoInput(true);
out = new PrintWriter(new OutputStreamWriter(conn.getOutputStream()));
out.print(param);
out.flush();
in = new BufferedReader(
new InputStreamReader(conn.getInputStream()));
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
int len = 0;
InputStream is = conn.getInputStream();
while ((len = is.read(buf)) != -1) {
System.out.println(len);
baos.write(buf, 0, len);
}
Linux OS,Tomcat server,"xxx.xxxx.com" is an incorrect URL.
I am expecting a UnknownHostException all the time, but sometimes what I am getting is UnknownHostException.
UnknownHostException error message
java.net.UnknownHostException: xxx.xxxx.com at
java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:178)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) at
java.net.Socket.connect(Socket.java:579) at
sun.net.NetworkClient.doConnect(NetworkClient.java:178) at
sun.net.www.http.HttpClient.openServer(HttpClient.java:432)
SocketTimeoutException error message
java.net.SocketTimeoutException: connect timed out at
java.net.PlainSocketImpl.socketConnect(Native Method) at
java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
at
java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
at
java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) at
java.net.Socket.connect(Socket.java:579) at
sun.net.NetworkClient.doConnect(NetworkClient.java:178) at
sun.net.www.http.HttpClient.openServer(HttpClient.java:432)

Just a guess - is it possible that sometimes your app can not connect to the DNS server? That would explain why you receive a SocketTimeoutException instead of an UnknownHostException - your app is trying to look up the hostname but it times out before it can determine that the host does not exist.

Error writing to server using Google API

URL url = new URL("https://www.google.com/speech-api/v2/recognize?output=json&lang=en-us&key=mykey");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "audio/x-flac; rate=16000");
conn.setUseCaches(false);
conn.setDoOutput(true);
conn.setDoInput(true);
conn.connect();
DataOutputStream wr = new DataOutputStream(conn.getOutputStream());
wr.write(bytearray);
wr.flush();
wr.close();
InputStream stream = conn.getInputStream(); //throws io exception
so basically I'm trying to send bytearray over httpurlconnection java.io.IOException: Error writing to server at last line.

How to send post parameter which can be read by php

I have some connection to url:
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
How I can send post parameter to this url that php function: http://www.php.net/manual/en/reserved.variables.request.php can read it ? I try to according this question: Java - sending HTTP parameters via POST method easily but with no success. It just display empty array
php code:
print_r($_REQUEST,1)
java code:
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setInstanceFollowRedirects(false);
connection.setRequestMethod("POST");
connection.setRequestProperty("category_name", categoryName);
connection.setRequestProperty("complete", complete);
DataOutputStream wr = new DataOutputStream(connection.getOutputStream());
connection.getResponseCode();
wr.flush();
wr.close();
connection.disconnect();

You forgot to set the Content-Type header, and you need to write the category_name and complete values as a string to the stream.
Quoting the code from the post you mentioned:
String urlParameters = "param1=a&param2=b&param3=c";
String request = "http://example.com/index.php";
URL url = new URL(request);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setDoInput(true);
connection.setInstanceFollowRedirects(false);
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.setRequestProperty("charset", "utf-8");
connection.setRequestProperty("Content-Length", "" + Integer.toString(urlParameters.getBytes().length));
connection.setUseCaches (false);
DataOutputStream wr = new DataOutputStream(connection.getOutputStream ());
wr.writeBytes(urlParameters);
wr.flush();
wr.close();
connection.disconnect();
As you can see, he sets the headers (Content-Type, Charset and Content-Length) and then writes the POST data to the stream.
The POST data is just like the GET format: key-value pairs seperated by &, and the key and value are seperated by =.
As the Content-Type is set to www-form-urlencoded, you need to 'url encode' the key and value values. You can do this using the URLEncoder.encode method.
The urlParameters for your POST data would be:
String urlParameters = "category_name=" + URLEncoder.encode(categoryName) + "&complete=" + URLEncoder.encode(complete);

How to set content-length in android?

I want to get content size by request.getContentLength() in server client JSP page.
But request.getContentLength() always return -1, i do not why?
Android snippet code:
URL uri = new URL(actionUrl);
HttpURLConnection conn = (HttpURLConnection) uri.openConnection();
//conn.setChunkedStreamingMode(100);
conn.setConnectTimeout(setTimeOut>0?setTimeOut:timeoutConnection);
conn.setReadTimeout(setTimeOut>0?setTimeOut:timeoutConnection);
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setRequestMethod("POST");
conn.setRequestProperty("Connection", "keep-alive");
//conn.setRequestProperty("content-length", "10");
//conn.addRequestProperty("content-length", "20");
conn.setFixedLengthStreamingMode(30);
conn.setRequestProperty("Charsert", ENCODING);
conn.setRequestProperty("Content-Type", "multipart/form-data"
+ ";boundary=" + java.util.UUID.randomUUID().toString());
conn.connect();

You are using conn.setChunkedStreamingMode(100) that will effectively enable the chunked transfer encoding in chunks of 100 bytes when the content-lenght is unknown in advance.
Use conn.setFixedLengthStreamingMode(int len) if you know in advance the length of the content you are going to send in the body of the request.