Error fetching source code from web page using eclipse

Question

I found online that we can use HttpClient and HttpGet objects to download the source code of a page using java. But, whenever I try to do so, my IDE(Eclipse) asks me to surround some lines of code with a try/catch block and it won't compile unless I do so. But then again, when I surround those lines with a try/catch block some variables go out of scope raising another error. Here's what's happening -

package com.example.prs;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;

public class PrsActivity extends Activity {

private TextView title;
private String url = "http://www.google.com";
private String pageHtml;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_prs); 
    title = (TextView) findViewById(R.id.title); 
    HttpClient client = new DefaultHttpClient();
    HttpGet request = new HttpGet(url);
    HttpResponse response = client.execute(request); // asks to add try/catch block here

    String html = "";
    InputStream in = response.getEntity().getContent(); //asks to add try/catch block here
    BufferedReader reader = new BufferedReader(new InputStreamReader(in));
    StringBuilder str = new StringBuilder();
    String line = null;
    while((line = reader.readLine()) != null)     // asks to add try/catch block here
    {
        str.append(line);
    }
    in.close(); // asks to add try/catch block here
    html = str.toString();
  }

  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_prs, menu);
    return true;
    }
  }

and when I add the try/catch block, these errors show up -

package com.example.prs;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;

public class PrsActivity extends Activity {

private TextView title;
private String url = "http://www.google.com";
private String pageHtml;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_prs); 
    title = (TextView) findViewById(R.id.title); 
    HttpClient client = new DefaultHttpClient();
    HttpGet request = new HttpGet(url);
    HttpResponse response;
    try {
        response = client.execute(request);
    } catch (ClientProtocolException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    String html = "";
    InputStream in;
    try {
        in = response.getEntity().getContent();     //"response" goes out of scope
    } catch (IllegalStateException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    BufferedReader reader = new BufferedReader(new InputStreamReader(in));
    StringBuilder str = new StringBuilder();
    String line = null;
    try {
        while((line = reader.readLine()) != null)
        {
            str.append(line);
        }
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    try {
        in.close();     //"in" goes out of scope
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    html = str.toString();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu`enter code here`.activity_prs, menu);
    return true;
   }
 }

Please help me to fix this problem. Thanks in advance.

Besides your compilation error, you will have a `NetworkOnMainThreadException` because you'll do some HTTP stuff on the UI thread. So please look at `AsyncTask`. — Alexis C., Jan 03 '14 at 20:17

score 0 · Accepted Answer · edited May 23 '17 at 11:50

Purely as a syntax matter, here is how you fix your Exception problem:

package com.example.prs;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;

public class PrsActivity extends Activity {

    private TextView title;
    private String url = "http://www.google.com";
    private String pageHtml;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_prs);
        title = (TextView) findViewById(R.id.title);
        HttpClient client = new DefaultHttpClient();
        HttpGet request = new HttpGet(url);

        try {
            HttpResponse response = client.execute(request); // asks to add
                                                                // try/catch
                                                                // block here

            String html = "";
            InputStream in = response.getEntity().getContent(); // asks to add
                                                                // try/catch
                                                                // block here
            BufferedReader reader = new BufferedReader(
                    new InputStreamReader(in));
            StringBuilder str = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) // asks to add try/catch
                                                        // block here
            {
                str.append(line);
            }
            in.close(); // asks to add try/catch block here
            html = str.toString();
        } catch (IOException err) {
            Log.e(PrsActivity.class.getSimpleName(), err.toString(), err);
        }
    }
}

However, as ZouZou pointed out in his comment, this still won't work because you are trying to execute a network request in your main thread. You need to create an AsyncTask and execute the network request there.

See this answer on how to create an AsyncTask.

Error fetching source code from web page using eclipse

1 Answers1