CODEWITHSUNDEEP
androidsdkbufferedreaderurlconnection
Kyle McBride
Kyle McBride

Reputation: 169

BufferReader Android

Hello i'm trying to set a simple connection to download the webpage source through an android application so i could later on use it in conjunction with my api. My code bellow show's no errors but in run time the application quits when this code is run. When i comment out the BufferReader line the application continues as normal so the problem must be with this line of code:

BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));

And bellow i've got the full code snippet from where i'm using it.

        currentCustomer.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            try {
                URL url = null;
                url = new URL("http:www.google.com");
                URLConnection conn = url.openConnection();
                BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
                String line = "";
                while((line = reader.readLine()) != null) {
                    tv.append(line);
                }
            } catch(Exception e) {

            }

        }
    });

Any help would be appreciated :)

And Here's the stack trace: 

06-15 16:15:50.911: D/dalvikvm(925): GC_FOR_ALLOC freed <1K, 4% free 7249K/7495K, paused 59ms
06-15 16:15:51.049: D/dalvikvm(925): GC_CONCURRENT freed <1K, 4% free 7249K/7495K, paused 5ms+4ms
06-15 16:15:51.159: V/TLINE(925): new: android.text.TextLine@40633f50
06-15 16:15:51.489: V/TLINE(925): new: android.text.TextLine@4063be20
06-15 16:15:55.019: W/System.err(925): java.lang.NullPointerException
06-15 16:15:55.039: W/System.err(925):  at      org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection$Address.hashCode(HttpConnection.java:296)
06-15 16:15:55.039: W/System.err(925):  at java.util.HashMap.get(HashMap.java:302)
06-15 16:15:55.039: W/System.err(925):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnectionPool.get(HttpConnectionPool.java:73)
06-15 16:15:55.039: W/System.err(925):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getHttpConnection(HttpURLConnectionImpl.java:292)
06-15 16:15:55.049: W/System.err(925):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.makeConnection(HttpURLConnectionImpl.java:274)
06-15 16:15:55.049: W/System.err(925):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.retrieveResponse(HttpURLConnectionImpl.java:1038)
06-15 16:15:55.049: W/System.err(925):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:523)
06-15 16:15:55.049: W/System.err(925):  at com.kylemcbride.SqueakyClean.SqueakyCleanActivity$1.onClick(SqueakyCleanActivity.java:48)
06-15 16:15:55.049: W/System.err(925):  at android.view.View.performClick(View.java:3100)
06-15 16:15:55.049: W/System.err(925):  at android.view.View$PerformClick.run(View.java:11644)
06-15 16:15:55.059: W/System.err(925):  at android.os.Handler.handleCallback(Handler.java:587)
06-15 16:15:55.059: W/System.err(925):  at android.os.Handler.dispatchMessage(Handler.java:92)
06-15 16:15:55.069: W/System.err(925):  at android.os.Looper.loop(Looper.java:126)
06-15 16:15:55.069: W/System.err(925):  at android.app.ActivityThread.main(ActivityThread.java:3997)
06-15 16:15:55.069: W/System.err(925):  at java.lang.reflect.Method.invokeNative(Native Method)
06-15 16:15:55.069: W/System.err(925):  at java.lang.reflect.Method.invoke(Method.java:491)
06-15 16:15:55.080: W/System.err(925):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
06-15 16:15:55.080: W/System.err(925):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
06-15 16:15:55.080: W/System.err(925):  at dalvik.system.NativeStart.main(Native Method)

Upvotes: 0

Views: 473

Answers (2)

metior
metior

Reputation: 385

You should use StringBuilder for concatenating string while getting data from a web source. Concatenating string every time slows established connection speed. Here is a reference for StringBuilder: http://developer.android.com/reference/java/lang/StringBuilder.html

EDITED Also when performing network operations, reading and writing from database or running services. Like you are trying to get data from a web source, its recommended to run these kind of tasks in a separate thread instead running on a main thread (aka UI thread). When you don't use the separate thread for this, you will always have to face exceptions and app crashes. The best solution for the work you are doing, you should use AsynchTask. Checkout these references:

See the Worker Thread section:
http://developer.android.com/guide/components/processes-and-threads.html
See what AsynchTask has to offer:
http://developer.android.com/reference/android/os/AsyncTask.html

Upvotes: 1

James Moore
James Moore

Reputation: 9026

You're trying to load the url:

http:www.google.com

Note the lack of slashes. It's not a real address.

Upvotes: 1

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