Q: HttpURLConnection throws java.io.IOException: insufficient data written I developed a dispatcher application and when I do tests I get the exception IOException: insufficient data written this is the part of code that's throws the error:
final int responseCode = connection.getResponseCode();

final HttpURLConnection connection = (HttpURLConnection) new URL(getUrl()).openConnection();
final int timeout =200;
final HttpRequestContext data = getData();//data contains the data send in the request to dispatche
connection.setConnectTimeout(timeout);
for (final Entry<String, List<String>> entry : data.getHeaders().entrySet()) {
    for (final String value : entry.getValue()) {
    connection.setRequestProperty(entry.getKey(), value);
    }
}
connection.setUseCaches(false);
connection.setDoInput(true);
connection.setDoOutput(true);
if (data.getContentLength() > 0) {
    connection.setFixedLengthStreamingMode(data.getContentLength());
}
connection.setReadTimeout(timeout);
connection.setRequestMethod(data.getMethod());
final int responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
    final HttpRequestContext data = getData();

if (ArrayUtils.isEmpty(data.getBody())) {
    LOGGER.debug("No data to send");
} else {
    IOUtils.write(data.getBody(), connection.getOutputStream());
}
}

Log: 
java.io.IOException: insufficient data written
at sun.net.www.protocol.http.HttpURLConnection$StreamingOutputStream.close(HttpURLConnection.java:3501)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1470)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1441)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480)
at com.dhl.dispatcher.HttpRequestWriter.doRun(HttpRequestWriter.java:78)
at com.dhl.dispatcher.AbstractRequestWriter.run(AbstractRequestWriter.java:73)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

thanks for your help. 

A: you never send any data but you set 
connection.setFixedLengthStreamingMode(data.getContentLength());

you need to do smth like this before u get the response:
        DataOutputStream out = new DataOutputStream(connection.getOutputStream());
        out.write(body);
        out.close();


UPDATE:
doing 

final int responseCode = connection.getResponseCode();

makes the request 
you have to add the body before that.

A: The following code can be deleted if it's not being used:
if (data.getContentLength() > 0) {
    connection.setFixedLengthStreamingMode(data.getContentLength());
}

This is the part of the code that's causing the insufficient data written exception.
