CODEWITHSUNDEEP
javaandroidservlets
Andi Domi
Andi Domi

Reputation: 751

Error while sending a GET Request to a servlet from android

after searching around im able to retreive a response from my servlet , but i cant send a parameter (a username and a password parameter) from android to a servlet! My logcat shows this error:

04-0java.lang.ClassCastException: org.apache.http.client.methods.HttpGet cannot be cast to org.apache.http.HttpResponse
at com.example.httpgetandroidexample.MainActivity$AsyncTaskRunner.doInBackground(MainActivity.java:76)
at com.example.httpgetandroidexample.MainActivity$AsyncTaskRunner.doInBackground(MainActivity.java:1)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)

and i cant understand why! Here it is my android main activity:

package com.example.httpgetandroidexample;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

               public TextView content;
                EditText name,pass;
                String URL,nameValue,passValue;
            @Override
            protected void onCreate(Bundle savedInstanceState) {

                      super.onCreate(savedInstanceState);
                     setContentView(R.layout.activity_main);

                     name      =  (EditText)findViewById(R.id.name);
                     pass       =  (EditText)findViewById(R.id.pass);
                     content       =  (TextView)findViewById(R.id.text);

                   Button button=(Button)findViewById(R.id.but);
                   try {
                    nameValue    =URLEncoder.encode(name.getText().toString(), "UTF-8");
                    passValue    =URLEncoder.encode(pass.getText().toString(), "UTF-8");
                       URL = "http://10.0.2.2:8080/login/web";
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                }

                   button.setOnClickListener(new View.OnClickListener() {
                       @Override
                       public void onClick(View v) {
                        AsyncTaskRunner runner = new AsyncTaskRunner();
                        runner.execute(new String[ ] { URL });
                       }
                      });


   }
            private class AsyncTaskRunner extends AsyncTask<String, Void, String> {


                @Override
                protected String doInBackground(String... urls) {

                  String response = "";
                  for (String url : urls) {
                    DefaultHttpClient client = new DefaultHttpClient();
                    HttpGet httpGet = new HttpGet(url);
                    try {
                        List<NameValuePair> postParameters = 
                                new ArrayList<NameValuePair>();
                            postParameters.add(new BasicNameValuePair("user",nameValue));
                            postParameters.add(new BasicNameValuePair("pass",passValue));
                            UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(
                                    postParameters);
                            ((HttpResponse) httpGet).setEntity(formEntity);
                      HttpResponse execute = client.execute(httpGet);
                      InputStream content = execute.getEntity().getContent();

                      BufferedReader buffer = new BufferedReader(new InputStreamReader(content));
                      String s = "";
                      while ((s = buffer.readLine()) != null) {
                        response += s;
                      }

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

                @Override
                protected void onPostExecute(String result) {
                  content.setText(result);
                }
              }
}

Does anyone have any idea?

UPDATE:

now i have changed my android code like this:
package com.example.httpgetandroidexample;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

               public TextView content;
                EditText name,pass;
                String URL;
            @Override
            protected void onCreate(Bundle savedInstanceState) {

                      super.onCreate(savedInstanceState);
                     setContentView(R.layout.activity_main);

                     name      =  (EditText)findViewById(R.id.name);
                     pass       =  (EditText)findViewById(R.id.pass);
                     content       =  (TextView)findViewById(R.id.text);

                   Button button=(Button)findViewById(R.id.but);
                   try {
                    String nameValue    ="user="+URLEncoder.encode(name.getText().toString(), "UTF-8");
                    String passValue    ="&pass="+URLEncoder.encode(pass.getText().toString(), "UTF-8");
                       URL = "http://10.0.2.2:8080/login/web?"+nameValue+passValue;
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                }

                   button.setOnClickListener(new View.OnClickListener() {
                       @Override
                       public void onClick(View v) {
                        AsyncTaskRunner runner = new AsyncTaskRunner();
                        runner.execute(new String[ ] { URL });
                       }
                      });


   }
            private class AsyncTaskRunner extends AsyncTask<String, Void, String> {


                @Override
                protected String doInBackground(String... urls) {

                  String response = "";
                  for (String url : urls) {
                    DefaultHttpClient client = new DefaultHttpClient();
                    HttpGet httpGet = new HttpGet(url);
                    try {

                      HttpResponse execute = client.execute(httpGet);
                      InputStream content = execute.getEntity().getContent();

                      BufferedReader buffer = new BufferedReader(new InputStreamReader(content));
                      String s = "";
                      while ((s = buffer.readLine()) != null) {
                        response += s;
                      }

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

                @Override
                protected void onPostExecute(String result) {
                  content.setText(result);
                }
              }
}

this time runs without logcat errors but the parameters does not come to the servlet!

Upvotes: 0

Views: 1043

Answers (2)

Andi Domi
Andi Domi

Reputation: 751

i have modified the activity and the problem was that the URL and nameValue and passValue was declared on the wrong section of the code ! Here it is the right android code:

package com.example.httpgetandroidexample;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

               public TextView content;
                EditText name,pass;
                String URL,nameValue,passValue;
            @Override
            protected void onCreate(Bundle savedInstanceState) {

                      super.onCreate(savedInstanceState);
                     setContentView(R.layout.activity_main);

                     name      =  (EditText)findViewById(R.id.name);
                     pass       =  (EditText)findViewById(R.id.pass);
                     content       =  (TextView)findViewById(R.id.text);
                     content.setText("Vendosni Perdoruesin dhe Fjalekalimin");
                   Button button=(Button)findViewById(R.id.but);



                   button.setOnClickListener(new View.OnClickListener() {
                       @Override
                       public void onClick(View v) {
                           nameValue="&user="+name.getText().toString();
                           passValue    ="&pass="+pass.getText().toString();
                           URL = "http://10.0.2.2:8080/login/web2?activitetiNR=1"+nameValue+passValue;
                        AsyncTaskRunner runner = new AsyncTaskRunner();

                           Log.i("url",URL);
                           Log.i("url",nameValue);
                           Log.i("url",passValue);
                        runner.execute(new String[ ] { URL });
                       }
                      });


   }
            private class AsyncTaskRunner extends AsyncTask<String, Void, String> {


                @Override
                protected String doInBackground(String... urls) {

                  String response = "";
                  for (String url : urls) {
                    DefaultHttpClient client = new DefaultHttpClient();
                    HttpGet httpGet = new HttpGet(url);
                    try {

                      HttpResponse execute = client.execute(httpGet);
                      InputStream content = execute.getEntity().getContent();

                      BufferedReader buffer = new BufferedReader(new InputStreamReader(content));
                      String s = "";
                      while ((s = buffer.readLine()) != null) {
                        response += s;
                      }

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

                @Override
                protected void onPostExecute(String result) {
                  content.setText(result);
                }
              }
}

Upvotes: 0

anonymous
anonymous

Reputation: 1317

Looking at the stack trace, I guess your problem is at this line.

((HttpResponse) httpGet).setEntity(formEntity);

Why are you casting it to HttpResponse?

OK. You want to send user/pass parameters using HTTP GET. For HTTP GET, all parameters are part of the URL. Maybe this can give you some help on how to perform a HTTP GET and pass parameters in. But in general, URL would look like this

http://www.blah.com/servlet?user="1234"&pass="password"

The stuff after the ? in the URL contains all the parameters. But there is a length limit in the URL, if you exceed that length, you'll have to use HTTP POST.

Try this link to see if it can help you http://androidexample.com/How_To_Make_HTTP_Get_Request_To_Server_-_Android_Example/index.php?view=article_discription&aid=63&aaid=88

Upvotes: 2

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