Express CheckOut-NullPointer Exception

[pavanravikanth]

Here is my Code Please Help me Get this... It is working with SandBox, But not working with Live Server...

Red Line is point of Exception: Checkout Class

/*==================================================================
PayPal Express Checkout Call
===================================================================
*/

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.infinte.adwords.PayPalFunctions;

public class CheckOut extends HttpServlet {

/**
*
*/
private static final long serialVersionUID = 1L;

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

// Use "request" to read incoming HTTP headers (e.g. cookies)
// and HTML form data (e.g. data the user entered and submitted)

// Use "response" to specify the HTTP response line and headers
// (e.g. specifying the content type, setting cookies).

/*
* The paymentAmount is the total value of ' the purchase. ' '
* TODO: Enter the total Payment Amount within the quotes. ' example :
* paymentAmount = "15.00";
*/
String paymentAmount = Double.toString(Double.parseDouble(request.getParameter("amount"))+10);

/*
* '------------------------------------ ' The returnURL is the location
* where buyers return to when a ' payment has been succesfully
* authorized. ' ' This is set to the value entered on the Integration
* Assistant '------------------------------------
*/

String returnURL = "abc.com";

/*
* '------------------------------------ ' The cancelURL is the location
* buyers are sent to when they hit the ' cancel button during
* authorization of payment during the PayPal flow ' ' This is set to
* the value entered on the Integration Assistant
* '------------------------------------
*/
String cancelURL = "xyz.com";

/*
* '------------------------------------ ' The items hashmap contains
* the details of each item '------------------------------------
* TODO: change "item name" to desired item name
*/

Map item = new HashMap();
item.put("name", "INFINITE::Credits");
item.put("amt", paymentAmount);
item.put("qty", "1");

/*
* '------------------------------------ ' Calls the SetExpressCheckout
* API call ' ' The SetExpressCheckout function is defined in the file
* PayPalFunctions.java,
* '-------------------------------------------------
*/
PayPalFunctions ppf = new PayPalFunctions();
HashMap nvp = ppf.setExpressCheckout(paymentAmount, returnURL,
cancelURL, item);
String strAck = (String) nvp.get("ACK");
if (strAck != null && strAck.equalsIgnoreCase("Success")) {

// ' Redirect to paypal.com
String redirectURL = "https://www.sandbox.paypal.com/incontext?token="
+ nvp.get("TOKEN").toString();

response.sendRedirect(redirectURL);
} else {
// Display a user friendly Error on the page using any of the
// following error information returned by PayPal

String ErrorCode = nvp.get("L_ERRORCODE0").toString();
String ErrorShortMsg = nvp.get("L_SHORTMESSAGE0").toString();
String ErrorLongMsg = nvp.get("L_LONGMESSAGE0").toString();
String ErrorSeverityCode = nvp.get("L_SEVERITYCODE0").toString();
}
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}

}

Paypalfunctions Class:

package com.infinte.adwords;

/**
* Created by IntelliJ IDEA.
* User: lhuynh
* Date: Dec 6, 2007
* Time: 5:06:52 PM
* To change this template use File | Settings | File Templates.
*/

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
import java.util.StringTokenizer;

import javax.servlet.http.HttpServletResponse;

public class PayPalFunctions {

private String gv_APIUserName;
private String gv_APIPassword;
private String gv_APISignature;

private String gv_APIEndpoint;
private String gv_BNCode;

private String gv_Version;
private String gv_nvpHeader;
private String gv_ProxyServer;
private String gv_ProxyServerPort;
private int gv_Proxy;
private boolean gv_UseProxy;
private String PAYPAL_URL;

public PayPalFunctions() {// lhuynh - Actions to be Done on init of this
// class

// Replace <API_USERNAME> with your API Username
// Replace <API_PASSWORD> with your API Password
// Replace <API_SIGNATURE> with your Signature

/*    API Credenttials are There....*/

boolean bSandbox = false;

/*
* Servers for NVP API Sandbox: https://api-3t.sandbox.paypal.com/nvp
* Live: https://api-3t.paypal.com/nvp
*/

/*
* Redirect URLs for PayPal Login Screen Sandbox:
* https://www.sandbox.paypal
* .com/webscr&cmd=_express-checkout&token=XXXX Live:
* https://www.paypal.
* com/cgi-bin/webscr?cmd=_express-checkout&token=XXXX
*/
String PAYPAL_DG_URL = null;
if (bSandbox == true) {
gv_APIEndpoint = "https://api-3t.sandbox.paypal.com/nvp";
PAYPAL_URL = "https://www.sandbox.paypal.com/webscr?cmd=_express-checkout&token=";
PAYPAL_DG_URL = "https://www.sandbox.paypal.com/incontext?token=";
} else {
gv_APIEndpoint = "https://api-3t.paypal.com/nvp";
PAYPAL_URL = "https://www.paypal.com/cgi-bin/webscr?cmd=_express-checkout&token=";
PAYPAL_DG_URL = "https://www.paypal.com/incontext?token=";
}

String HTTPREQUEST_PROXYSETTING_SERVER = "";
String HTTPREQUEST_PROXYSETTING_PORT = "";
boolean USE_PROXY = false;

gv_Version = "84";

// WinObjHttp Request proxy settings.
gv_ProxyServer = HTTPREQUEST_PROXYSETTING_SERVER;
gv_ProxyServerPort = HTTPREQUEST_PROXYSETTING_PORT;
gv_Proxy = 2; // 'setting for proxy activation
gv_UseProxy = USE_PROXY;

}

/*********************************************************************************
* SetExpressCheckout: Function to perform the SetExpressCheckout API call
*
* Inputs: paymentAmount: Total value of the purchase currencyCodeType:
* Currency code value the PayPal API paymentType: 'Sale' for Digital Goods
* returnURL: the page where buyers return to after they are done with the
* payment review on PayPal cancelURL: the page where buyers return to when
* they cancel the payment review on PayPal
*
* Output: Returns a HashMap object containing the response from the server.
*********************************************************************************/
public HashMap setExpressCheckout(String paymentAmount, String returnURL,
String cancelURL, Map item) {

/*
* '------------------------------------ ' The currencyCodeType and
* paymentType ' are set to the selections made on the Integration
* Assistant '------------------------------------
*/

String currencyCodeType = "USD";
String paymentType = "Sale";

/*
* Construct the parameter string that describes the PayPal payment the
* varialbes were set in the web form, and the resulting string is
* stored in $nvpstr
*/
String nvpstr = "&PAYMENTREQUEST_0_AMT=" + paymentAmount
+ "&PAYMENTREQUEST_0_PAYMENTACTION=" + paymentType
+ "&RETURNURL=" + URLEncoder.encode(returnURL) + "&CANCELURL="
+ URLEncoder.encode(cancelURL)
+ "&PAYMENTREQUEST_0_CURRENCYCODE=" + currencyCodeType
+ "&REQCONFIRMSHIPPING=0" + "&NOSHIPPING=1"
+ "&L_PAYMENTREQUEST_0_NAME0=" + item.get("name")
+ "&L_PAYMENTREQUEST_0_AMT0=" + item.get("amt")
+ "&L_PAYMENTREQUEST_0_QTY0=" + item.get("qty")
+ "&L_PAYMENTREQUEST_0_ITEMCATEGORY0=Digital";

/*
* Make the call to PayPal to get the Express Checkout token If the API
* call succeded, then redirect the buyer to PayPal to begin to
* authorize payment. If an error occured, show the resulting errors
*/

HashMap nvp = httpcall("SetExpressCheckout", nvpstr);

String strAck = nvp.get("ACK").toString();
if (strAck != null && strAck.equalsIgnoreCase("Success")) {

return nvp;
}

return null;
}

/*********************************************************************************
* GetShippingDetails: Function to perform the GetExpressCheckoutDetails API
* call
*
* Inputs: None
*
* Output: Returns a HashMap object containing the response from the server.
*********************************************************************************/
public HashMap getPaymentDetails(String token) {
/*
* Build a second API request to PayPal, using the token as the ID to
* get the details on the payment authorization
*/

String nvpstr = "&TOKEN=" + token;

/*
* Make the API call and store the results in an array. If the call was
* a success, show the authorization details, and provide an action to
* complete the payment. If failed, show the error
*/

HashMap nvp = httpcall("GetExpressCheckoutDetails", nvpstr);
String strAck = nvp.get("ACK").toString();

if (strAck != null
&& (strAck.equalsIgnoreCase("Success") || strAck
.equalsIgnoreCase("SuccessWithWarning"))) {

return nvp;
}
return null;
}

/*********************************************************************************
* ConfirmPayment: Function to perform the DoExpressCheckoutPayment API call
*
* Inputs: None
*
* Output: Returns a HashMap object containing the response from the server.
*********************************************************************************/
public HashMap confirmPayment(String token, String payerID,
String finalPaymentAmount, String serverName, Map item) {

/*
* '------------------------------------ ' The currencyCodeType and
* paymentType ' are set to the selections made on the Integration
* Assistant '------------------------------------
*/
String currencyCodeType = "USD";
String paymentType = "Sale";

/*
* '----------------------------------------------------------------------------
* '---- Use the values stored in the session from the previous SetEC
* call
* '----------------------------------------------------------------------------
*/
String nvpstr = "&TOKEN=" + token + "&PAYERID=" + payerID
+ "&PAYMENTREQUEST_0_PAYMENTACTION=" + paymentType + "&PAYMENTREQUEST_0_AMT="
+ finalPaymentAmount;

nvpstr = nvpstr + "&PAYMENTREQUEST_0_CURRENCYCODE=" + currencyCodeType + "&IPADDRESS="
+ serverName;

nvpstr = nvpstr + "&L_PAYMENTREQUEST_0_NAME0=" + item.get("name")
+ "&L_PAYMENTREQUEST_0_AMT0=" + item.get("amt")
+ "&L_PAYMENTREQUEST_0_QTY0=" + item.get("qty")
+ "&L_PAYMENTREQUEST_0_ITEMCATEGORY0=Digital";

/*
* Make the call to PayPal to finalize payment If an error occured, show
* the resulting errors
*/
HashMap nvp = httpcall("DoExpressCheckoutPayment", nvpstr);
String strAck = nvp.get("ACK").toString();
if (strAck != null
&& (strAck.equalsIgnoreCase("Success") || strAck
.equalsIgnoreCase("SuccessWithWarning"))) {
return nvp;
}
return null;

}

/*********************************************************************************
* httpcall: Function to perform the API call to PayPal using API signature @
* methodName is name of API method. @ nvpStr is nvp string. returns a NVP
* string containing the response from the server.
*********************************************************************************/
public HashMap httpcall(String methodName, String nvpStr) {

String version = "2.3";
String agent = "Mozilla/4.0";
String respText = "";
HashMap nvp = null; // lhuynh not used?

// deformatNVP( nvpStr );
String encodedData = "METHOD=" + methodName + "&VERSION=" + gv_Version
+ "&PWD=" + gv_APIPassword + "&USER=" + gv_APIUserName
+ "&SIGNATURE=" + gv_APISignature + nvpStr;

try {
URL postURL = new URL(gv_APIEndpoint);
HttpURLConnection conn = (HttpURLConnection) postURL
.openConnection();

// Set connection parameters. We need to perform input and output,
// so set both as true.
conn.setDoInput(true);
conn.setDoOutput(true);

// Set the content type we are POSTing. We impersonate it as
// encoded form data
conn.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded");
conn.setRequestProperty("User-Agent", agent);

// conn.setRequestProperty( "Content-Type", type );
conn.setRequestProperty("Content-Length",
String.valueOf(encodedData.length()));
conn.setRequestMethod("POST");

// get the output stream to POST to.
DataOutputStream output = new DataOutputStream(
conn.getOutputStream());
output.writeBytes(encodedData);
output.flush();
output.close();

// Read input from the input stream.
DataInputStream in = new DataInputStream(conn.getInputStream());
int rc = conn.getResponseCode();
if (rc != -1) {
BufferedReader is = new BufferedReader(new InputStreamReader(
conn.getInputStream()));
String _line = null;
while (((_line = is.readLine()) != null)) {
respText = respText + _line;
}
nvp = deformatNVP(respText);
}
return nvp;
} catch (IOException e) {
// handle the error here
return null;
}
}

/*********************************************************************************
* deformatNVP: Function to break the NVP string into a HashMap pPayLoad is
* the NVP string. returns a HashMap object containing all the name value
* pairs of the string.
*********************************************************************************/
public HashMap deformatNVP(String pPayload) {
HashMap nvp = new HashMap();
StringTokenizer stTok = new StringTokenizer(pPayload, "&");
while (stTok.hasMoreTokens()) {
StringTokenizer stInternalTokenizer = new StringTokenizer(
stTok.nextToken(), "=");
if (stInternalTokenizer.countTokens() == 2) {
String key = URLDecoder.decode(stInternalTokenizer.nextToken());
String value = URLDecoder.decode(stInternalTokenizer
.nextToken());
nvp.put(key.toUpperCase(), value);
}
}
return nvp;
}

/*********************************************************************************
* RedirectURL: Function to redirect the user to the PayPal site token is
* the parameter that was returned by PayPal returns a HashMap object
* containing all the name value pairs of the string.
*********************************************************************************/
public void RedirectURL(HttpServletResponse response, String token) {
String payPalURL = PAYPAL_URL + token;

// response.sendRedirect( payPalURL );
response.setStatus(302);
response.setHeader("Location", payPalURL);
response.setHeader("Connection", "close");
}

// end class
}