Read contents of a URL in Android

Question

I'm new to android and I'm trying to figure out how to get the contents of a URL as a String. For example if my URL is http://www.google.com/ I want to get the HTML for the page as a String. Could anyone help me with this?

score 51 · Accepted Answer · edited Jun 13 '12 at 06:31

51

From the Java Docs : readingURL

URL yahoo = new URL("http://www.yahoo.com/");
BufferedReader in = new BufferedReader(
            new InputStreamReader(
            yahoo.openStream()));

String inputLine;

while ((inputLine = in.readLine()) != null)
    System.out.println(inputLine);

in.close();

Instead of writing each line to System.out just append it to a string.

edited Jun 13 '12 at 06:31

Praveenkumar

24,084
23
95
173

answered Jan 16 '10 at 01:30

Drew

2,269
21
16

4

Thanks, I tried that before and I just realized my problem: I forgot to give it internet permissions... – user200565 Jan 16 '10 at 01:54
2

If you post code examples which seem to be doing the right thing, it gives everyone else a chance to figure out what else could be causing the problem (like your permission issue). – Drew Jan 16 '10 at 02:10
can you get it all in one string at once or do you have to append it line by line? – gonzobrains Jul 14 '11 at 12:36
2

since API 11 remeber about http://stackoverflow.com/questions/6343166/android-os-networkonmainthreadexception – Selvin Sep 17 '13 at 15:28
2

the code should be inside AsyncTask or any background thread. – iDeveloper Oct 18 '17 at 12:55

score 6 · Answer 2 · answered Jul 09 '15 at 15:05

6

You can open a stream and read and append each line to a string - remember to wrap everything with a try-catch block - hope it helps!

String fullString = "";
URL url = new URL("http://example.com");
BufferedReader reader = new BufferedReader(new InputStreamReader(url.openStream()));
String line;
while ((line = reader.readLine()) != null) {
    fullString += line;
}
reader.close();

answered Jul 09 '15 at 15:05

nurnachman

4,468
2
37
40

1

How would I write the try-catch block? I'm pretty new and Java is telling me to handle exceptions. Also: fullString is the output, isn't it? – Saman Miran Apr 25 '16 at 09:16
@SamanMiran try-catch is used in java for doing something that might raise an exception, and catching that exception. try {// do something risky } catch (Exception exception) {// handle it} – nurnachman Apr 28 '16 at 12:15
@SamanMiran yes - fullString is the output; you can see that it starts as an empty string ("") and in every loop of the while block - another line is being added to it in the end – nurnachman Apr 28 '16 at 12:16
Using String like that is very bad: you allocate a new String object in every step of the loop. Use a StringBuilder instead, and append to it. Use StringBuilder.toString() to get the resulting String. – noamtm Dec 28 '17 at 11:59

score 5 · Answer 3 · answered Jun 07 '18 at 22:55

You can put it in an AsyncTask like this:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main2);

    try {
        new Main2Activity.MyTask().execute(this);

    } catch (Exception e) {
        e.printStackTrace();
    }
}

private static class MyTask extends AsyncTask<Object, Void, String> {

    Main2Activity activity;

    @Override
    protected String doInBackground(Object... params) {
        activity = (Main2Activity)params[0];
        try {
            StringBuilder sb = new StringBuilder();
            URL url = new URL("http://www.google.com/");

            BufferedReader in;
            in = new BufferedReader(
                    new InputStreamReader(
                            url.openStream()));

            String inputLine;
            while ((inputLine = in.readLine()) != null)
                sb.append(inputLine);

            in.close();

            return sb.toString();

        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    @Override
    protected void onPostExecute(String str) {
        //Do something with result string
        WebView webView = activity.findViewById(R.id.web_view);
        webView.loadData(str, "text/html; charset=UTF-8", null);
    }

}

Read contents of a URL in Android

3 Answers3

Linked