Integrate Paypal in Web Application using Java

Question

I want to integrate paypal in my web application. I am using RESTEasy API for restful requests. I want to know that how to integrate paypal in my application. I have dowonloaded paypal java sdk from their web site but right now I have no good applicaion which will help me to integrate paypal in my app. Can anybody suggest any site which shows step by step inegration of paypal in website or simple to understand ?

Answer 1

We have to follow the below step for configuring paypal in java web application.Here i have shown the configuration for Paypal to Paypal and CreditCard to Paypal payment.

1.create one sandbox account.
2.create web application.
3.Integrate the following struts2 action with your code.If you want to use with any other then just take methods and use directly.

public class PaypalAction extends ActionSupport implements SessionAware {


    private static final long serialVersionUID = 1L;
    private String resultString;
    private String token;

    @SuppressWarnings("rawtypes")
    private Map finalMap = new HashMap();

    public void paypalPay() {
        HttpServletRequest request = ServletActionContext.getRequest();
        HttpServletResponse response = ServletActionContext.getResponse();
        Integer payPercent = 10;     
        Map result = new HashMap();
        String data1 = "";

        try {
            data1 = URLEncoder.encode("USER", "UTF-8") + "="+ URLEncoder.encode("Sandbox UserName","UTF-8");
            data1 += "&" + URLEncoder.encode("PWD", "UTF-8") + "="+ URLEncoder.encode("Sandbox Password", "UTF-8");
            data1 += "&" + URLEncoder.encode("SIGNATURE", "UTF-8") + "="+ URLEncoder.encode("Sandbox Signature","UTF-8");
            data1 += "&" + URLEncoder.encode("METHOD", "UTF-8") + "="+ URLEncoder.encode("SetExpressCheckout", "UTF-8");

            data1 += "&" + URLEncoder.encode("RETURNURL", "UTF-8") + "=" + URLEncoder.encode(request.getRequestURL().toString().replaceAll(request.getServletPath(), "") + "/successPage","UTF-8");
            data1 += "&" + URLEncoder.encode("CANCELURL", "UTF-8") + "="+ URLEncoder.encode(request.getRequestURL().toString().replaceAll(request.getServletPath(), "") + "/failurePage",   "UTF-8");

            data1 += "&" + URLEncoder.encode("VERSION", "UTF-8") + "="+ URLEncoder.encode("104.0", "UTF-8");            
            data1 += "&" + URLEncoder.encode("AMT", "UTF-8")+ "=" + URLEncoder.encode("10", "UTF-8");                       
            data1 += "&" + URLEncoder.encode("CURRENCYCODE", "UTF-8") + "=" + URLEncoder.encode("USD", "UTF-8");            
            data1 += "&" + URLEncoder.encode("L_NAME0", "UTF-8") + "=" + URLEncoder.encode("Sample Test", "UTF-8");
            data1 += "&" + URLEncoder.encode("L_AMT0", "UTF-8") + "=" + URLEncoder.encode("10", "UTF-8");                   
            data1 += "&" + URLEncoder.encode("CUSTOM", "UTF-8") + "="+ URLEncoder.encode("Thank You For business","UTF-8");         
            data1 += "&" + URLEncoder.encode("DESC", "UTF-8") + "=" + URLEncoder.encode("Product Details", "UTF-8");                    
            data1 += "&" + URLEncoder.encode("NOSHIPPING", "UTF-8") + "="+ URLEncoder.encode("1", "UTF-8");


        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        result = post(data1);



        Iterator<?> iter = result.entrySet().iterator();

        while (iter.hasNext()) {
            Map.Entry mEntry = (Map.Entry) iter.next();

        }

        if(result!=null){

            token = (String) result.get("TOKEN");
            String url = "https://www.sandbox.paypal.com/cgi-bin/webscr?cmd=_express"+ "-" + "checkout&token=" + (String) result.get("TOKEN");
            try {
                response.sendRedirect(url);
            } catch (IOException e) {

                e.printStackTrace();
            }

        }


    }

    public String successPage() {
        HttpServletRequest request = ServletActionContext.getRequest();

        String payerID = request.getParameter("PayerID");
        String token=request.getParameter("token");
        doPaypalPayment(payerID,token);
        return "success";
    }


    public String failurePage()
    {

        return "failurePage";
    }


    public void doPaypalPayment(String payerID, String token2) {
        Map result = new HashMap();
        String data = "";
        try {

            data1 = URLEncoder.encode("USER", "UTF-8") + "="+ URLEncoder.encode("Sandbox UserName","UTF-8");
            data1 += "&" + URLEncoder.encode("PWD", "UTF-8") + "="+ URLEncoder.encode("Sandbox Password", "UTF-8");
            data1 += "&" + URLEncoder.encode("SIGNATURE", "UTF-8") + "="+ URLEncoder.encode("Sandbox Signature","UTF-8");

            data += "&" + URLEncoder.encode("METHOD", "UTF-8") + "="+ URLEncoder.encode("DoExpressCheckoutPayment", "UTF-8");
            data += "&" + URLEncoder.encode("PAYERID", "UTF-8") + "="+ URLEncoder.encode(payerID, "UTF-8");
            data += "&" + URLEncoder.encode("PAYMENTACTION", "UTF-8") + "="+ URLEncoder.encode("Sale", "UTF-8");
            data += "&" + URLEncoder.encode("TOKEN", "UTF-8") + "="+ URLEncoder.encode(token2, "UTF-8");
            data += "&" + URLEncoder.encode("AMT", "UTF-8") + "="+ URLEncoder.encode("10", "UTF-8");
            data += "&" + URLEncoder.encode("VERSION", "UTF-8") + "="+ URLEncoder.encode("104.0", "UTF-8");
            data += "&" + URLEncoder.encode("CURRENCYCODE", "UTF-8") + "="+ URLEncoder.encode("USD", "UTF-8");

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }

        result = post(data);    
    }


     public void deformatNVP()
        {   
            try
            {
                String delims = "[&]";
                String equals = "[=]";
                String[] tokens = this.resultString.split(delims);

                for(int i = 0; i < tokens.length; i++)
                {
                    String[] newTokens = tokens[i].split(equals);
                    this.finalMap.put(URLDecoder.decode(newTokens[0], "UTF-8"), URLDecoder.decode(newTokens[1], "UTF-8"));
                }

            } catch (Exception e) {
                System.out.println(e.toString());
            }
            //return finalMap;
        }

        public Map post(String data)
        {
            try
            {
                //Connect to the url
                URL url = new URL("https://api-3t.sandbox.paypal.com/nvp");
                URLConnection conn = url.openConnection();
                conn.setDoOutput(true);
                OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
                //Post the data
                wr.write(data);
                wr.flush();

                // Get the response
                BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
                this.resultString = rd.readLine();
                deformatNVP();
                wr.close();
                rd.close();

            } catch (Exception e) {
                System.out.println(e.toString());
            }
            return finalMap;  
        }





        @Override
        public void setSession(Map<String, Object> arg0) {
            // TODO Auto-generated method stub

        }


         public void doPaypalPaymentWithCreditCard() {
                try 
                {
                    //Load the caller service

                    //Create a new map to hold the result
                    Map result = new HashMap();

                    // Construct data request string
                   String data1 = URLEncoder.encode("USER", "UTF-8") + "="+ URLEncoder.encode("Sandbox UserName","UTF-8");
                   data1 += "&" + URLEncoder.encode("PWD", "UTF-8") + "="+ URLEncoder.encode("Sandbox Password", "UTF-8");
                   data1 += "&" + URLEncoder.encode("SIGNATURE", "UTF-8") + "="+ URLEncoder.encode("Sandbox Signature","UTF-8");                    data += "&" + URLEncoder.encode("METHOD", "UTF-8") + "=" + URLEncoder.encode("DoDirectPayment", "UTF-8");
                    data += "&" + URLEncoder.encode("AMT", "UTF-8") + "=" + URLEncoder.encode("20.10", "UTF-8");
                    data += "&" + URLEncoder.encode("VERSION", "UTF-8") + "=" + URLEncoder.encode("80.0", "UTF-8");
                    data += "&" + URLEncoder.encode("IPADDRESS", "UTF-8") + "=" + URLEncoder.encode("192.168.1.0", "UTF-8");
                    data += "&" + URLEncoder.encode("PAYMENTACTION", "UTF-8") + "=" + URLEncoder.encode("Sale", "UTF-8");
                    data += "&" + URLEncoder.encode("CREDITCARDTYPE", "UTF-8") + "=" + URLEncoder.encode("Visa", "UTF-8");
                    data += "&" + URLEncoder.encode("ACCT", "UTF-8") + "=" + URLEncoder.encode("4532513511140817", "UTF-8");
                    data += "&" + URLEncoder.encode("EXPDATE", "UTF-8") + "=" + URLEncoder.encode("102014", "UTF-8");
                    data += "&" + URLEncoder.encode("CVV2", "UTF-8") + "=" + URLEncoder.encode("123", "UTF-8");
                    data += "&" + URLEncoder.encode("FIRSTNAME", "UTF-8") + "=" + URLEncoder.encode("Jason", "UTF-8");
                    data += "&" + URLEncoder.encode("LASTNAME", "UTF-8") + "=" + URLEncoder.encode("Michels", "UTF-8");
                    data += "&" + URLEncoder.encode("STREET", "UTF-8") + "=" + URLEncoder.encode("123", "UTF-8");
                    data += "&" + URLEncoder.encode("CITY", "UTF-8") + "=" + URLEncoder.encode("Papillion", "UTF-8");
                    data += "&" + URLEncoder.encode("STATE", "UTF-8") + "=" + URLEncoder.encode("NE", "UTF-8");
                    data += "&" + URLEncoder.encode("ZIP", "UTF-8") + "=" + URLEncoder.encode("68046", "UTF-8");
                    data += "&" + URLEncoder.encode("COUNTRYCODE", "UTF-8") + "=" + URLEncoder.encode("US", "UTF-8");


                    result = post(data);

                    //This will iterate through the entire response map
                    Iterator iter = result.entrySet().iterator();
                    while (iter.hasNext()) {
                            Map.Entry mEntry = (Map.Entry) iter.next();
                            System.out.println(mEntry.getKey() + " : " + mEntry.getValue());
                    }

                    //Now that you have a response check to see if it is a success
                    String ack = "" + result.get("ACK");
                    if("Success".equals(ack))
                    {
                        System.out.println("Congratulations your transaction was a success");
                    }
                    else
                    {
                        System.out.println("There was an error with your request.");
                    }
                } 
                catch (Exception e) 
                {
                    System.out.println(e.toString());
                }
            }//end of main function




}

This is working fine for me.Hope it will help to those who want to configure payment through paypal.

Answer 2

Paypal offers a few examples and even a wizard that generates you some code.

After the previous links gone offline start with this small tutorial: https://developer.paypal.com/docs/checkout/integrate/#