CODEWITHSUNDEEP
javaandroidfile-io
JmRag
JmRag

Reputation: 1459

Read file from url java to android problems

I have a txt file at the online storage that my university offers me and I want to read it at an android application. I've managed to do this in Java but when I try to do this in Android nothing happens. The Eclipse suggestions changes the code and nothing works. Please help me I am new to android development.

The a.txt file has content: This is a message!

This is the java code:

import java.io.*;
import java.net.*;

public class Java_Parser {    

        public static void main(String[] args) throws Exception {

            URL oracle = new URL("http://cgi.di.uoa.gr/~std10108/a.txt");
            BufferedReader in = new BufferedReader(
            new InputStreamReader(oracle.openStream()));

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

And the output is, as it should be : This is a message!

I have added the internet permission to the manifest so it's not the problem. I copy paste it in a function on an android project and after the suggestions of Eclipse it turns to this:

//This a function called when a button is clicked
 public void OnClick(View view){


        URL oracle = null;
         BufferedReader in = null;
 String inputLine;

         String text=null;

        try {
            oracle = new URL("http://cgi.di.uoa.gr/~std10108/a.txt");
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        try {
            in = new BufferedReader(
            new InputStreamReader(oracle.openStream()));
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


        try {
            while ((inputLine = in.readLine()) != null)
                text=text + inputLine;
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        try {
            in.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


        EditText edittext= (EditText) findViewById(R.id.editText1);
        edittext.setText(text);

    }

The application compiles succesfully but when I try to run it and click the button, it crashes. Can you help me?

This is the logcat

> 11-20 17:40:04.089: I/Process(9926): Sending signal. PID: 9926 SIG: 9
> 11-20 17:50:37.009: D/libEGL(10534): loaded
> /system/lib/egl/libEGL_mali.so 11-20 17:50:37.014: D/libEGL(10534):
> loaded /system/lib/egl/libGLESv1_CM_mali.so 11-20 17:50:37.014:
> D/libEGL(10534): loaded /system/lib/egl/libGLESv2_mali.so 11-20
> 17:50:37.024: D/(10534): Device driver API match 11-20 17:50:37.024:
> D/(10534): Device driver API version: 10 11-20 17:50:37.024:
> D/(10534): User space API version: 10  11-20 17:50:37.024: D/(10534):
> mali: REVISION=Linux-r2p4-02rel0 BUILD_DATE=Tue Oct 16 15:37:13 KST
> 2012  11-20 17:50:37.054: D/OpenGLRenderer(10534): Enabling debug mode
> 0 11-20 17:50:39.449: D/AndroidRuntime(10534): Shutting down VM 11-20
> 17:50:39.449: W/dalvikvm(10534): threadid=1: thread exiting with
> uncaught exception (group=0x416d22a0) 11-20 17:50:39.454:
> E/AndroidRuntime(10534): FATAL EXCEPTION: main 11-20 17:50:39.454:
> E/AndroidRuntime(10534): java.lang.IllegalStateException: Could not
> execute method of the activity 11-20 17:50:39.454:
> E/AndroidRuntime(10534):  at
> android.view.View$1.onClick(View.java:3704) 11-20 17:50:39.454:
> E/AndroidRuntime(10534):  at
> android.view.View.performClick(View.java:4232) 11-20 17:50:39.454:
> E/AndroidRuntime(10534):  at
> android.view.View$PerformClick.run(View.java:17318) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> android.os.Handler.handleCallback(Handler.java:615) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> android.os.Handler.dispatchMessage(Handler.java:92) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> android.os.Looper.loop(Looper.java:137) 11-20 17:50:39.454:
> E/AndroidRuntime(10534):  at
> android.app.ActivityThread.main(ActivityThread.java:4921) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> java.lang.reflect.Method.invokeNative(Native Method) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> java.lang.reflect.Method.invoke(Method.java:511) 11-20 17:50:39.454:
> E/AndroidRuntime(10534):  at
> com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
> 11-20 17:50:39.454: E/AndroidRuntime(10534):  at
> com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> dalvik.system.NativeStart.main(Native Method) 11-20 17:50:39.454:
> E/AndroidRuntime(10534): Caused by:
> java.lang.reflect.InvocationTargetException 11-20 17:50:39.454:
> E/AndroidRuntime(10534):  at
> java.lang.reflect.Method.invokeNative(Native Method) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> java.lang.reflect.Method.invoke(Method.java:511) 11-20 17:50:39.454:
> E/AndroidRuntime(10534):  at
> android.view.View$1.onClick(View.java:3699) 11-20 17:50:39.454:
> E/AndroidRuntime(10534):  ... 11 more 11-20 17:50:39.454:
> E/AndroidRuntime(10534): Caused by:
> android.os.NetworkOnMainThreadException 11-20 17:50:39.454:
> E/AndroidRuntime(10534):  at
> android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1118)
> 11-20 17:50:39.454: E/AndroidRuntime(10534):  at
> java.net.InetAddress.lookupHostByName(InetAddress.java:385) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> java.net.InetAddress.getAllByNameImpl(InetAddress.java:236) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> java.net.InetAddress.getAllByName(InetAddress.java:214) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> libcore.net.http.HttpConnection.<init>(HttpConnection.java:70) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> libcore.net.http.HttpConnection.<init>(HttpConnection.java:50) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
> 11-20 17:50:39.454: E/AndroidRuntime(10534):  at
> libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
> 11-20 17:50:39.454: E/AndroidRuntime(10534):  at
> libcore.net.http.HttpConnection.connect(HttpConnection.java:128) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:315)
> 11-20 17:50:39.454: E/AndroidRuntime(10534):  at
> libcore.net.http.HttpEngine.connect(HttpEngine.java:310) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:289)
> 11-20 17:50:39.454: E/AndroidRuntime(10534):  at
> libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:239) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    at
> libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:273)
> 11-20 17:50:39.454: E/AndroidRuntime(10534):  at
> libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:168)
> 11-20 17:50:39.454: E/AndroidRuntime(10534):  at
> java.net.URL.openStream(URL.java:462) 11-20 17:50:39.454:
> E/AndroidRuntime(10534):  at
> com.example.test.MainActivity.OnClick(MainActivity.java:55) 11-20
> 17:50:39.454: E/AndroidRuntime(10534):    ... 14 more

Edit1: I added the Internet permission but nothing changed

Upvotes: 0

Views: 3585

Answers (5)

xdevs23
xdevs23

Reputation: 1

You can use a PHP file on your server to display it.

First, you have to create an webview.

On the PHP file write the following code:

<!doctype html>
<html xmlns="http://w3.org/1999/xhtml">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <meta http-equiv="Cache-Control" content="no-Cache" />
    <title>Somewhat</title>
    <style type="text/css">body {font-family: sans-serif;}</style>
</head>

<body>
    <?php
      $yourfile = fopen("path/to/file.txt", "r");
      $contentoffile = fread($yourfile, 1024);
      fclose($yourfile);
    ?>
    <p><?php echo $contentoffile; ?></p>
</body>

Upvotes: 0

Shubhendu
Shubhendu

Reputation: 1

oracle.openConnection.getInputStream() would fit better ..

Upvotes: 0

Rahul Gupta
Rahul Gupta

Reputation: 5295

Add this code in the onCreate method :-

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();

StrictMode.setThreadPolicy(policy);

ADD this to ManiFestFile: 

<uses-permission android:name="android.permission.INTERNET"/>

Upvotes: 1

Grambot
Grambot

Reputation: 4523

Your issue is rooted in this exception: android.os.NetworkOnMainThreadException

The android system protects long blocks on using the Internet during the UI thread to prevent apps from becoming unresponsive. To properly download a file on the main thread you'll want to use some sort of Asynchronous thread to download the file and do a callback to the main thread to process it.

Start with looking into the AsyncTask here or searching for the exception itself on this site to help find numerous examples.

Upvotes: 1

M. Mimpen
M. Mimpen

Reputation: 1232

Have you set the correct permissions in the AndroidManifest.xml? For example, the android.permission.INTERNET permission would be required:

public static final String INTERNET. Allows applications to open network sockets. Constant Value: "android.permission.INTERNET"

For debugging purposes, it may be easy to just pack all the code in one try-catch statement, as is being done below:

try {
    URL oracle = new URL("http://cgi.di.uoa.gr/~std10108/a.txt");
    BufferedReader in = new BufferedReader(new InputStreamReader(oracle.openStream()));
    String inputLine;
    while ((inputLine = in.readLine()) != null)
        System.out.println(inputLine);
    in.close();
} catch (Exception e) {
    e.printStackTrace();
}

Upvotes: 0

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