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Processing large input Stream to List String in Java

Hey I am having a file nearly 110MB size at apache. I am reading that file into input stream and then converting that input stream to List of String based on all suggestion i find on stack overflow. But still i am facing out of memory issue.
Below is my code.
private List<String> readFromHttp(String url, PlainDiff diff) throws Exception {
HttpUrlConnection con = new HttpUrlConnection();
con.setGetUrl(url);
List<String> lines = new ArrayList<String>();
final String PREFIX = "stream2file";
final String SUFFIX = ".tmp";
final File tempFile = File.createTempFile(PREFIX, SUFFIX);
tempFile.deleteOnExit();
StringBuilder sb = new StringBuilder();
try {
InputStream data = con.sendGetInputStream();
if(data==null)
throw new UserAuthException("diff is not available at the location");
else {
try (FileOutputStream out = new FileOutputStream(tempFile)) {
IOUtils.copy(data, out);
LineIterator it = FileUtils.lineIterator(tempFile, "UTF-8");
try {
while (it.hasNext()) {
String line = it.nextLine();
lines.add(line);
sb.append(line);
}
} finally {
LineIterator.closeQuietly(it);
}
}
data.close();
diff.setLineAsString(sb.toString());
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//System.out.println(lines);
return lines;
}
public InputStream sendGetInputStream() throws IOException {
String encoding = Base64.getEncoder().encodeToString(("abc:$xyz$").getBytes("UTF-8"));
URL obj = new URL(getGetUrl());
// Setup the connection
HttpURLConnection con = (HttpURLConnection) obj.openConnection();
// Set the parameters from the headers
con.setRequestMethod("GET");
con.setDoOutput(true);
con.setRequestProperty ("Authorization", "Basic " + encoding);
InputStream is;
int responseCode = con.getResponseCode();
logger.info("GET Response Code :: " + responseCode);
if (responseCode == HttpURLConnection.HTTP_OK) {
is = con.getInputStream();
}
else {
is = null;
}
return is;
}
Is something in memory i am doing that is consuming lot of heap? Is there a better way to do it?

Your code has multiple issues. I am not going to solve each and every issue but point that out so that you can review your code and learn to write better code.
In method readFromHttp(..):
There is no need to create a new file by IOUtils.copy(data, out);
No use of String Builder StringBuilder sb = new StringBuilder();
No use of line iterator LineIterator
And there are multiple other memory-related issues but for the time being correct these points and test with the below-mentioned code.
Change your reading lines from file to very simple way after correcting the above mistakes:
try(BufferedReader reader = new BufferedReader(new InputStreamReader(data, StandardCharsets.UTF_8))) {
for (String line; (line = reader.readLine()) != null;) {
lines.add(line);
}
}

Issue with Retrieving JSON from Webpage Android

So I'm facing some difficulty in trying to, what seems simply, obtain a JSON file from a webpage, and then parse it on Android. I have already built the parser, and tested it in Eclipse (in fact, all of the code works in Eclipse). However, when I run the HttpURLConnection and try to retrieve the JSON data in a string in Android Studio, I end up getting no exceptions and an almost empty string (I think I am getting the 1st, 2nd, 3rd, and last character, but not too sure). I have included parts of the code below, and
URL url = null;
HttpURLConnection urc = null;
try {
url = new URL(query);
urc = (HttpURLConnection) url.openConnection();
InputStream in = new BufferedInputStream(urc.getInputStream());
jsoncontent = readStream(in);
System.out.println(jsoncontent);
} catch (MalformedURLException e) {
e.printStackTrace();
}
catch (IOException e) {
e.printStackTrace();
}
finally {
urc.disconnect();
}
The code for readStream() is below
private static String readStream(InputStream is) throws IOException {
StringBuilder sb = new StringBuilder();
BufferedReader r = new BufferedReader(new InputStreamReader(is),1000);
for (String line = r.readLine(); line != null; line =r.readLine()){
sb.append(line);
}
is.close();
return sb.toString();
}

Here is an exact chunk from an assignment I did last semester:
URL u = new URL(url);
HttpURLConnection conn = (HttpURLConnection) u.openConnection();
conn.setRequestMethod("GET");
conn.setRequestProperty("Accept", "text/html");
BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
JSONObject searchResults = new JSONObject(in.readLine());
...
conn.disconnect();
You seem to be missing setRequestMethod("GET") and setRequestProperty("Accept", "text/html") in your code. Hope this helps.

Grabbing JSON works from one link, not from another

I'm doing a simple JSON grab from two links with the same code. I'm doing it two separate times, so the cause of my issue isn't because they're running into each other or something.
Here is my code:
#Override
protected String doInBackground(Object... params) {
try {
URL weatherUrl = new URL("my url goes here");
HttpURLConnection connection = (HttpURLConnection) weatherUrl
.openConnection();
connection.connect();
responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
InputStream inputStream = connection.getInputStream();
Reader reader = new InputStreamReader(inputStream);
int contentLength = connection.getContentLength();
char[] charArray = new char[contentLength];
reader.read(charArray);
String responseData = new String(charArray);
Log.v("test", responseData);
When I try this with:
http://www.google.com/calendar/feeds/developer-calendar#google.com/public/full?alt=json
I get an error of having an array lenth of -1
For this link:
http://api.openweathermap.org/data/2.5/weather?id=5815135
It returns fine and I get a log of all of the JSON. Does anyone have any idea why?
Note: I tried stepping through my code in debug mode, but I couldn't catch anything. I also downloaded a Google chrome extension for parsing json in the browser and both urls look completely valid. I'm out of ideas.

Log this: int contentLength = connection.getContentLength();
I don't see the google url returning a content-length header.
If you just want String output from a url, you can use Scanner and URL like so:
Scanner s = new Scanner(new URL("http://www.google.com").openStream(), "UTF-8").useDelimiter("\\A");
out = s.next();
s.close();
(don't forget try/finally block and exception handling)
The longer way (which allows for progress reporting and such):
String convertStreamToString(InputStream is) throws UnsupportedEncodingException {
BufferedReader reader = new BufferedReader(new
InputStreamReader(is, "UTF-8"));
StringBuilder sb = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null)
sb.append(line + "\n");
} catch (IOException e) {
// Handle exception
} finally {
try {
is.close();
} catch (IOException e) {
// Handle exception
}
}
return sb.toString();
}
}
and then call String response = convertStreamToString( inputStream );

How to download/read html file via ftp url?

I am having trouble getting the html text from this html file via ftp. I use beautiful soup to read an html file via http/https but for some reason I cannot download/read from an ftp. Please help!
Here is the url.
a link
Here is my code so far.
BufferedReader reader = null;
String total = "";
String line;
ur = "ftp://ftp.legis.state.tx.us/bills/832/billtext/html/house_resolutions/HR00001_HR00099/HR00014I.htm"
try {
URL url = new URL(ur);
URLConnection urlc = url.openConnection();
InputStream is = urlc.getInputStream(); // To download
reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
while ((line = reader.readLine()) != null)
total += reader.readLine();
} finally {
if (reader != null)
try { reader.close();
} catch (IOException logOrIgnore) {}
}

This code working for me, Java 1.7.0_25. Notice that you were storing one of every two lines, calling reader.readLine() both in the condition and in the body of the while loop.
public static void main(String[] args) throws MalformedURLException, IOException {
BufferedReader reader = null;
String total = "";
String line;
String ur = "ftp://ftp.legis.state.tx.us/bills/832/billtext/html/house_resolutions/HR00001_HR00099/HR00014I.htm";
try {
URL url = new URL(ur);
URLConnection urlc = url.openConnection();
InputStream is = urlc.getInputStream(); // To download
reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
while ((line = reader.readLine()) != null) {
total += line;
}
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException logOrIgnore) {
}
}
}
}

First thought this is related to a wrong path resolution as discussed here but this does not help.
I don't know what is exactly going wrong here but I can only reproduce this error on this ftp-server and with the MacOS Java 1.6.0_33-b03-424. I can't reproduce it with Java 1.7.0_25. So perhaps you check for a Java update.
Or you could use commons FTPClient to retrieve the file:
FTPClient client = new FTPClient();
client.connect("ftp.legis.state.tx.us");
client.enterLocalPassiveMode();
client.login("anonymous", "");
client.changeWorkingDirectory("bills/832/billtext/html/house_resolutions/HR00001_HR00099");
InputStream is = client.retrieveFileStream("HR00014I.htm");

How to convert the DataInputStream to the String in Java?

I want to ask a question about Java. I have use the URLConnection in Java to retrieve the DataInputStream. and I want to convert the DataInputStream into a String variable in Java. What should I do? Can anyone help me. thank you.
The following is my code:
URL data = new URL("http://google.com");
URLConnection dataConnection = data.openConnection();
DataInputStream dis = new DataInputStream(dataConnection.getInputStream());
String data_string;
// convent the DataInputStream to the String

import java.net.*;
import java.io.*;
class ConnectionTest {
public static void main(String[] args) {
try {
URL google = new URL("http://www.google.com/");
URLConnection googleConnection = google.openConnection();
DataInputStream dis = new DataInputStream(googleConnection.getInputStream());
StringBuffer inputLine = new StringBuffer();
String tmp;
while ((tmp = dis.readLine()) != null) {
inputLine.append(tmp);
System.out.println(tmp);
}
//use inputLine.toString(); here it would have whole source
dis.close();
} catch (MalformedURLException me) {
System.out.println("MalformedURLException: " + me);
} catch (IOException ioe) {
System.out.println("IOException: " + ioe);
}
}
}
This is what you want.

You can use commons-io IOUtils.toString(dataConnection.getInputStream(), encoding) in order to achieve your goal.
DataInputStream is not used for what you want - i.e. you want to read the content of a website as String.

If you want to read data from a generic URL (such as www.google.com), you probably don't want to use a DataInputStream at all. Instead, create a BufferedReader and read line by line with the readLine() method. Use the URLConnection.getContentType() field to find out the content's charset (you will need this in order to create your reader properly).
Example:
URL data = new URL("http://google.com");
URLConnection dataConnection = data.openConnection();
// Find out charset, default to ISO-8859-1 if unknown
String charset = "ISO-8859-1";
String contentType = dataConnection.getContentType();
if (contentType != null) {
int pos = contentType.indexOf("charset=");
if (pos != -1) {
charset = contentType.substring(pos + "charset=".length());
}
}
// Create reader and read string data
BufferedReader r = new BufferedReader(
new InputStreamReader(dataConnection.getInputStream(), charset));
String content = "";
String line;
while ((line = r.readLine()) != null) {
content += line + "\n";
}