util.servlet.PaypalListenerServlet.java Source code

Introduction

Here is the source code for util.servlet.PaypalListenerServlet.java

Source

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package util.servlet;

import com.paypal.core.Constants;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
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;

/**
 *
 * @author gerasim
 */
public class PaypalListenerServlet extends HttpServlet {

    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        HttpClient client = new DefaultHttpClient();
        HttpPost post = new HttpPost(Constants.IPN_SANDBOX_ENDPOINT);
        List<NameValuePair> params = new ArrayList<>();
        params.add(new BasicNameValuePair("cmd", "_notify-validate")); //You need to add this parameter to tell PayPal to verify
        for (Enumeration<String> e = request.getParameterNames(); e.hasMoreElements();) {
            String name = e.nextElement();
            String value = request.getParameter(name);
            params.add(new BasicNameValuePair(name, value));
        }
        post.setEntity(new UrlEncodedFormEntity(params));
        String rc = getRC(client.execute(post)).trim();
        if ("VERIFIED".equals(rc)) {
            //Your business code comes here
        }
    }

    private String getRC(HttpResponse response) throws IOException, IllegalStateException {
        InputStream is = response.getEntity().getContent();
        BufferedReader br = new BufferedReader(new InputStreamReader(is));
        String result = "";
        String line = null;
        while ((line = br.readLine()) != null) {
            result += line;
        }
        return result;
    }

}