We Keep Coding

"IllegalsStateException closed" in HttpUrlConnection while download file

I have random IllegalstateException crash in Fabric. But can't reproduce it.
Users download file from server. For download I use regular HttpUrlConnection and read bytes from InputStream in while. Call this in foreground service with separate thread. On some iteration of reading this crash happen. I close InputStream only in finally, so it can't be closed before while finish.
Android 6, 7, 8, 9. Interesting that 100% Samsung, maybe Samsung has some specific behavior? Also interesting that this happen always near finish of download. For example from 2738688 bytes was downloaded 2716156 and only 22532‬ left. All crashes near the end of download.
public static Response downloadFile(String url, String tmpFile) throws IOException {
InputStream is = null;
OutputStream os = null;
Response result;
try {
URL urlFile = new URL(url);
HttpURLConnection connection = (HttpURLConnection) urlFile.openConnection();
connection.connect();
long size = connection.getContentLength();
int code = connection.getResponseCode();
Map<String, List<String>> responseHeaders = connection.getHeaderFields();
result = new Response(code, size, responseHeaders);
if (code != HttpURLConnection.HTTP_OK) {
return result;
}
is = connection.getInputStream();
os = new FileOutputStream(tmpFile);
final byte[] buf = new byte[1024];
int read;
//This read random crash
while ((read = is.read(buf)) != -1) {
os.write(buf, 0, read);
}
os.flush();
} finally {
if (is != null) {
is.close();
}
if (os != null) {
os.close();
}
}
return result;
}

Java gzip pdf from url to file - result gives minor character mismatch

I'm trying to download a gzip pdf from an url, unpacking it and writing it to a file. It almost works, but currently some characters in the pdf made from my code mismatches the real pdf. I checked this by opening both of the pdf's in notepad.
I provide some short text samples from the two pdfs.
From my code:
’8 /qªMiUe°Ä[H`ðKíulýªäqvA®v8;xÒhÖßÚ²ý!Æ¢ØK$áýçpF[¸t1#y$93
From the real pdf:
ƒ8 /qªMiUe°Ä[H`ðKíulªäqvA®—v8;ŸÒhÖßÚ²!ˆ¢ØK$áçpF[¸t1#y$‘‹3
Here is my code:
public void readPDFfromURL(String urlStr) throws IOException {
URL myURL = new URL(urlStr);
HttpURLConnection urlCon = (HttpURLConnection) myURL.openConnection();
urlCon.setRequestProperty("Accept-Encoding", "gzip");
urlCon.setRequestProperty("Content-Type", "application/pdf");
urlCon.setRequestMethod("GET");
urlCon.setDoInput(true);
urlCon.connect();
Reader reader;
if ("gzip".equals(urlCon.getContentEncoding())) {
reader = new InputStreamReader(new GZIPInputStream(urlCon.getInputStream()));
}
else {
reader = new InputStreamReader(urlCon.getInputStream());
}
FileOutputStream fos = new FileOutputStream("document.pdf");
int data = reader.read();
while(data != -1) {
char c = (char) data;
fos.write(c);
data = reader.read();
}
fos.close();
reader.close();
}
I can open the pdf, and it has the correct amount of pages, but the pages are all blank.
My initial thought is that it might got something to do with character codes to do, like some setting in my java project, intellij etc.
Alternatively, I don't actually need to put it in a file. I just need to download it so I can upload it to another place. However, the pdf should of course be working in either case. I'm really just putting it in an actual file to check if it works.
Thank you for your help!

Here is my new implementation, which solves my question:
public void readPDFfromURL(String urlStr) throws IOException {
URL myURL = new URL(urlStr);
HttpURLConnection urlCon = (HttpURLConnection) myURL.openConnection();
urlCon.setRequestProperty("Accept-Encoding", "gzip");
urlCon.setRequestProperty("Content-Type", "application/pdf");
urlCon.setRequestMethod("GET");
urlCon.setDoInput(true);
urlCon.connect();
GZIPInputStream reader = new GZIPInputStream(urlCon.getInputStream());
FileOutputStream fos = new FileOutputStream("document.pdf");
byte[] buffer = new byte[1024];
int len;
while((len = reader.read(buffer)) != -1){
fos.write(buffer, 0, len);
}
fos.close();
reader.close();
}

Exception in thread "main" java.lang.IllegalStateException: Already connected

I'm trying to invoke a webservice call and get a response. When I tried it first time it worked perfectly and printed the response. But after that one run, how many ever times I run it, i throws me
Exception in thread "main" java.lang.IllegalStateException: Already connected
at sun.net.www.protocol.http.HttpURLConnection.setRequestProperty(Unknown Source)
at SOAPClient4XG.main(SOAPClient4XG.java:72)
I have tried various solutions provided for similar problem (like connect / disconnect) but nothing seems to make it work. I understand that it tries to perform an operation on already existing connection, but not sure how to fix. I'm fairly new to all this and I need help.
Below is my code
import java.io.*;
import java.net.*;
public class SOAPClient4XG
{
private static HttpURLConnection httpConn;
public static void main(String[] args) throws Exception {
String SOAPUrl = args[0];
String xmlFile2Send = args[1];*/
String SOAPUrl = "http://10.153.219.88:8011/celg-svcs-soap/business/ApplicantEligibility";
String xmlFile2Send =
"C:\\Users\\dkrishnamoorthy\\workspace\\SOAPUI_Automation\\src\\ApplicantElligibilty.xml";
String SOAPAction = "";
if (args.length > 2)
SOAPAction = args[2];
// Create the connection where we're going to send the file.
URL url = new URL(SOAPUrl);
URLConnection connection = url.openConnection();
//URLConnection connection = new URLConnection(url);
httpConn = (HttpURLConnection) connection;
if(httpConn.getResponseCode()==500)
{
System.out.println("Error Stream for 500 : "+httpConn.getErrorStream());
}
// Open the input file. After we copy it to a byte array, we can see
// how big it is so that we can set the HTTP Cotent-Length
// property. (See complete e-mail below for more on this.)
FileInputStream fin = new FileInputStream(xmlFile2Send);
ByteArrayOutputStream bout = new ByteArrayOutputStream();
// Copy the SOAP file to the open connection.
copy(fin,bout);
fin.close();
byte[] b = bout.toByteArray();
// Set the appropriate HTTP parameters.
httpConn.setRequestProperty( "Content-Length",
String.valueOf( b.length ) );
httpConn.setRequestProperty("Content-Type","text/xml; charset=utf-8");
httpConn.setRequestProperty("SOAPAction",SOAPAction);
httpConn.setRequestMethod( "POST" );
httpConn.setDoOutput(true);
httpConn.setDoInput(true);
// httpConn.connect();
// Everything's set up; send the XML that was read in to b.
OutputStream out = httpConn.getOutputStream();
out.write( b );
out.close();
// Read the response and write it to standard out.
InputStreamReader isr =
new InputStreamReader(httpConn.getInputStream());
BufferedReader in = new BufferedReader(isr);
String inputLine;
System.out.println("Printing the Response ");
while ((inputLine = in.readLine()) != null)
System.out.println(inputLine);
in.close();
}
public static void copy(InputStream in, OutputStream out)
throws IOException {
synchronized (in) {
synchronized (out) {
byte[] buffer = new byte[256];
while (true) {
int bytesRead = in.read(buffer);
if (bytesRead == -1) break;
out.write(buffer, 0, bytesRead);
}
}
}
}
}

If you use eclipse version just restart it. I met the same issue and I sorted out by doing that .

I solved this because I had a forgotten watch for connection.getResponseCode() in my debugging interface in NetBeans. Hope it might help others making the same mistake.
If you have any watch relative to the response value of the request, such as getResponseCode(), getResponseMessage(), getInputStream() or even just connect(), you will get this error in debugging mode.
All of the previous methods implicitly call connect() and fire the request. So when you reach setDoOutput, the connection is already made.

java.net.sockettimeout exception: Read Timed Out

I am reading the "interests" of a user using Facebook API.
When I am trying to read the URL using the following code, I am getting java.net.sockettimeoutexception:
public static String readURL(URL url) throws IOException{
ByteArrayOutputStream baos = new ByteArrayOutputStream();
URLConnection con = url.openConnection();
con.setConnectTimeout(20000);
con.setReadTimeout(20000);
InputStream is = con.getInputStream();
int r;
while ((r = is.read()) != -1) {
baos.write(r);
}
return new String(baos.toByteArray());
}
How can I handle this now? What should I do?

Increase the values of:
con.setConnectTimeout(20000);
con.setReadTimeout(20000);
and add a catch for that exception.

HTTPRequest Get Data in Java

I would like to do an HTTPRequest in Java and then get the data from the server (it's not a webpage the data come from a database).
I try this but the getData doesn't work.
Do you know how I can get the Data?
public static void main(String args[]) throws Exception {
URL url = new URL("http://ip-ad.com");
HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
System.out.println("Request method is " + httpCon.getData());
}
Thanks

You can get the response body of the web request as an InputStream with:
httpCon.getInputStream();
From there it depends on what the format of the response data is. If it's XML then pass it to a library to parse XML. If you want to read it into a String see: Reading website's contents into string. Here's an example of writing it to a local file:
InputStream in = httpCon.getInputStream();
OutputStream out = new FileOutputStream("file.dat");
out = new BufferedOutputStream(out);
byte[] buf = new byte[8192];
int len = 0;
while ((len = in.read(buf)) != -1) {
out.write(buf, 0, len);
}
out.close();

You can use http://jersey.java.net/ .
It's a simple lib for your needs.