get data from remote server in android

Question

I am using oracle db and weblogic as web server. From my android app i am able to send parameters to my remote server.. My PROBLEM is HOW TO GET THE RESULT SET GENERATED BY

Answer 1

The best thing you can do is to implement JSON with a RESTFUL Web Service.

More info:

1. JSON.ORG

2. How to create a JSON response

3. Android includes JSON classes such as JSONArray, JSONObject that can be used to interpret the response the Web Service will return. See more at here.

You can't go wrong. JSON is fast, there are ways to secure the communication if you implement RESTFUL Authentication.

Best of all your Web Service will be compatible with iOS Apps and any other platform with JSON support.

Good luck!

Answer 2

The code to be witten in android should be this:

package com.campuspro.start;

import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
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 Login_Menu extends Activity {

EditText usname;
EditText pass;
TextView tv;
HttpClient client;
HttpPost post;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.login_lay);
 tv=(TextView) findViewById(R.id.login_stat_tv);
 usname=(EditText)findViewById(R.id.uname);
 pass=(EditText)findViewById(R.id.pass);
Button login=(Button)findViewById(R.id.login_but);
Button cancel=(Button)findViewById(R.id.cancel_but);

client = new DefaultHttpClient();
String url="http://10.0.2.2:7001/proj/login.jsp";//your url
post = new HttpPost(url);
login.setOnClickListener(new View.OnClickListener() {

    public void onClick(View arg0) {
        new Login().execute("");
    }
});

cancel.setOnClickListener(new View.OnClickListener() {

    public void onClick(View v) {
        usname.getText().clear();
        pass.getText().clear();
    }
});

 }




private class Login extends AsyncTask<String, Void, JSONObject>{
ProgressDialog dialog = ProgressDialog.show(Login_Menu.this, "", "Authenticating, Please wait...");

@Override
protected JSONObject doInBackground(String... params) {
    Log.i("thread", "Doing Something...");
   //authentication operation
try{

    List<NameValuePair> pairs = new ArrayList<NameValuePair>();   
    pairs.add(new BasicNameValuePair("username",usname.getText().toString()));   
    pairs.add(new BasicNameValuePair("password",pass.getText().toString()));   
    post.setEntity(new UrlEncodedFormEntity(pairs));   
    HttpResponse response = client.execute(post);
    int status=response.getStatusLine().getStatusCode();

    if(status == 200)
    {
        HttpEntity e=response.getEntity();
        String data=EntityUtils.toString(e);
        JSONObject last=new JSONObject(data);
        return last;

    }

}

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

}

    return null;
}

protected void onPreExecute(){
    //dialog.dismiss();
    Log.i("thread", "Started...");
    dialog.show();
}
protected void onPostExecute(JSONObject result){
    Log.i("thread", "Done...");
    String status;
    String name;
    try {
        status= result.getString("status");
        name=result.getString("uname");

       if(dialog!=null)
       {
         dialog.dismiss();
       }
       else{}

     if(status.equalsIgnoreCase("yes"))
          {
        tv.setText("Login Successful...");

        Bundle newbundle=new Bundle();
        newbundle.putString("uname",name);

        Intent myIntent=new Intent(Login_Menu.this,Instruction.class);
        myIntent.putExtras(newbundle);

        startActivity(myIntent);

        }
      else{

            tv.setText("No User Found, please try again!");
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }
  }

}

}

And the server side JSP code should be:

<%@page contentType="text/html; charset=UTF-8"%>
<%@page import="org.json.simple.JSONObject"%>
<%@page import="java.util.*,java.sql.*"%>

<%!

Connection con;
PreparedStatement ps;
ResultSet rs;
String x,y;

%>

<%
 Class.forName("oracle.jdbc.driver.OracleDriver");

 con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:XE","db_username","db_password");
x=request.getParameter("username");
y=request.getParameter("password");

ps=con.prepareStatement("select * from table_name where suid=? and spwd=?");
ps.setString(1,x);
ps.setString(2,y);
rs=ps.executeQuery();


JSONObject obj=new JSONObject();
if(rs.next())
{
String uname=rs.getString(4);
obj.put("status","yes");
obj.put("uname",uname);
out.print(obj);

}
else
{
obj.put("status","no");
out.print(obj);
}
out.flush();
 %>