paypal支付标准按钮（from表单）集成

1.简介

　　PayPal是倍受全球亿万用户追捧的国际贸易支付工具，即时支付，即时到账，全中文操作界面，能通过中国的本地银行轻松提现，解决外贸收款难题，助您成功开展海外业务，决胜全球。注册PayPal后就可立即开始接受信用卡付款。作为在线付款服务商，PayPal是您向全世界近2.54亿的用户敞开大门的最快捷的方式。最大的好处是，注册完全免费！集国际流行的信用卡，借记卡，电子支票等支付方式于一身。帮助买卖双方解决各种交易过程中的支付难题。PayPal是名副其实的全球化支付平台， 服务范围超过200个市场， 支持的币种超过100个。 在跨国交易中， 将近70%的在线跨境买家更喜欢用PayPal支付海外购物款项。

　　PayPal提供了多种支付方式：

• 标准支付
• 快速支付
• 其中标准支付誉为最佳实践。

　　注意：paypal支付国内账号不能付款给国内账号

2.PayPal的相关URL

　　正式网址：https://www.paypal.com/ 

　　沙箱（开发者）网址：https://developer.paypal.com/

　　沙箱（测试用户）登录地址：https://www.sandbox.paypal.com/

　　技术支持地址（paypal开发人员）：https://www.paypal-support.com/s/account-overview

　　官方文档：

• 付款按钮资料：https://developer.paypal.com/docs/integration/web/
• IPN（支付回调）资料：https://developer.paypal.com/docs/api-basics/notifications/ipn/ht-ipn/
• PDT（数据传输）资料：https://developer.paypal.com/docs/api-basics/notifications/payment-data-transfer/#get-started
• PDT示例代码：https://github.com/paypal/pdt-code-samples

3.集成步骤

　　1、在paypal页面创建Buttons（PayPal付款按钮）并复制代码到项目

　　2、用户点击支付按钮

　　3、进入PayPal支付页面

　　4、用户登录后确认支付

　　5、显示支付成功信息

4.集成步骤实现

（1）注册账号

　　在PayPal正式网站https://www.paypal.com中注册一个账号，如果公司没有给你相关信息的话，先注册一个个人账号也是一样的。

（2）进入开发者界面创建相关信息

　　1、在开发者平台https://developer.paypal.com/，登录刚创建的账号

　　2、登录成功后，选择：SANBOX下的Accounts标签

　　3、创建个人账号和商家账号用于测试沙箱环境

（3）创建按钮

　　1、在PayPal沙箱测试账号网站https://www.sandbox.paypal.com/登录刚刚创建的沙箱商家账号

　　2、创建支付按钮

（4）PDT令牌获取

（5）IPN回调乱码处理

（6）示例代码

　　控制器代码如下：

@Controller
@RequestMapping("/paypalC")
public class PaypalC {

    @Autowired
    private PaypalS paypalS;

    //TODO 标准付款按钮集成
    /**交易取消
     */
    @RequestMapping(method = RequestMethod.GET, value = "cancel")
    public String cancel(){
        return "b2/paypal/cancel";
    }
    
    /**获取标准付款页面
     */
    @RequestMapping(method = RequestMethod.GET, value = "standardPayment", produces="text/html;charset=UTF-8")
    public String standardPayment(){
        return "b2/paypal/standardPayment";
    }
    
    /**PDT立即回调（由用户在paypal点击返回商家网站时调用，不点击则不会调用，含跳转路径）
     */
    @RequestMapping(value = "pdtWebhooks", produces="text/html;charset=UTF-8")
    public String pdtWebhooks(HttpServletRequest req, HttpServletResponse resp){
        return paypalS.pdtWebhooks(req, resp);
    }
    
    /**IPN回调（由paypal支付成功后调用，最多重复调用15次）
     */
    @ResponseBody
    @RequestMapping(method = RequestMethod.POST, value = "ipnWebhooks", produces="text/html;charset=UTF-8")
    public String ipnWebhooks(HttpServletRequest req, HttpServletResponse resp) {
        return paypalS.ipnWebhooks(req, resp);
    }
}

　　业务层代码如下：

import java.util.ArrayList;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.springframework.stereotype.Service;
import com.grt.b2.method.PaypalUtils;
import com.grt.v3.method.OUtils;

/**Paypal支付service类
 */
@Service
public class PaypalS {
    //TODO 标准付款按钮集成
    /**PDT立即回调（由用户在paypal点击返回商家网站时调用，不点击则不会调用，含跳转路径）
     */
    public String pdtWebhooks(HttpServletRequest req, HttpServletResponse resp) {
        String tx = req.getParameter("txn_id");//订单id
        String stringRes = PaypalUtils.getPDTWebHooks(tx);
        if(!OUtils.isEmpty(stringRes)){
            String[] res = stringRes.split("\r?\n");
            if("SUCCESS".equals(res[0])){
                System.out.println("验证PDT数据成功，进行订单入库");
                Map<String, String> data = new HashMap<String, String>();
                for (String str : res) {
                    if(str.indexOf("=") > 0){
                        String[] s = str.split("=");
                        data.put(s[0], s.length > 1 ? s[1] : "");
                    }
                }
                return "b2/paypal/success";
            }
        }
        return "b2/paypal/failure";
    }
    
    /**IPN回调（由paypal支付成功后调用，最多重复调用15次）
     */
    @SuppressWarnings("unchecked")
    public String ipnWebhooks(HttpServletRequest req, HttpServletResponse resp) {
        //1.获取ipn传递的数据
        Map<String, String> data = new HashMap<String, String>();
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("cmd", "_notify-validate"));
        Enumeration<String> e = req.getParameterNames();
        while(e.hasMoreElements()){
            String name = e.nextElement();
            String value = req.getParameter(name);
            params.add(new BasicNameValuePair(name, value));
            data.put(name, value);
        }
        //2.把ipn传递数据发送给paypal并获取返回数据进行验证
        String res = PaypalUtils.getIPNWebHooks(params);
        System.out.println("IPN数据
"+res);
        if ("VERIFIED".equals(res)) {//验证IPN回调数据成功
            System.out.println("验证IPN回调数据成功，进行订单入库");
        }else if("INVALID".equals(res)) {//验证IPN回调数据失败
            System.out.println("验证IPN回调数据失败，进行日志记录");
        }else{//验证IPN回调数据异常
            System.out.println("验证IPN回调数据异常，进行日志记录");
        }
        return "";
    }
}

　　PayPal工具类如下：

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.http.Consts;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import com.grt.michael.method.tigo.HttpsUtils;
import com.grt.v3.method.OUtils;

/**Paypal支付工具类
 */
public class PaypalUtils {
    //TODO 标准付款按钮集成
    private static final String SANDBOX_URL = "https://www.sandbox.paypal.com/cgi-bin/webscr";
    private static final String LIVE_URL = "https://www.paypal.com/cgi-bin/webscr";
    private static final String pdt_key = "";//PDT密钥，需要自己去paypal拿
    /**获取PDT验证数据
     */
    public static String getPDTWebHooks(String tx){
        Map<String, String> headers = new HashMap<String, String>();
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        headers.put("Content-Type", "application/x-www-form-urlencoded");
        params.add(new BasicNameValuePair("cmd", "_notify-synch"));
        params.add(new BasicNameValuePair("tx", tx));
        params.add(new BasicNameValuePair("at", pdt_key));
        String result = sendPost(SANDBOX_URL, headers, params);
        if(!OUtils.isEmpty(result))
            return URLDecoderString(result);
        return result;
    }
    /**获取IPN验证数据
     */
    public static String getIPNWebHooks(List<NameValuePair> params){
        Map<String, String> headers = new HashMap<String, String>();
        headers.put("Content-Type", "application/x-www-form-urlencoded");
        return sendPost(SANDBOX_URL, headers, params);
    }
    /**URL编码解码
     */
    public static String URLDecoderString(String str) {
        String result = "";
        try {
            result = java.net.URLDecoder.decode(str, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return result;
    }
    /**post请求方法
     */
    private static String sendPost(String url, Map<String, String> headers, List<NameValuePair> params) {
        String resultData = null;
        try{
            CloseableHttpClient http = HttpsUtils.getHttpClient();
            HttpPost httpost = new HttpPost(url);
            //设置header
            if (headers != null && headers.size() > 0) {
                for (Map.Entry<String, String> entry : headers.entrySet()) {
                    httpost.setHeader(entry.getKey(), entry.getValue());
                }
            }
            //组织请求参数
             if (params != null && params.size() > 0) {
                 httpost.setEntity(new UrlEncodedFormEntity(params, Consts.UTF_8));
             }
            // 执行结果
            for (int i = 0; i < 3; i++) {
                try {
                    HttpResponse res = http.execute(httpost);
                    if (res.getStatusLine().getStatusCode() != 200)
                        continue;
                    resultData = EntityUtils.toString(res.getEntity());
                    return resultData;
                } catch (IOException e) {
                    e.printStackTrace();
                    continue;
                } finally {
                    httpost.releaseConnection();
                }
            }
        }catch (Exception e) {
            e.printStackTrace();
        }
        return resultData;
    }
}

　　HttpUtils工具类（httpclient-4.5.jar、httpcore-4.4.1.jar）如下：

import org.apache.commons.collections.MapUtils;
import org.apache.http.*;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.conn.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.NoopHostnameVerifier;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.TrustStrategy;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.ssl.SSLContextBuilder;
import org.apache.http.util.EntityUtils;
import java.io.IOException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class HttpsUtils {
    private static final String HTTP = "http";
    private static final String HTTPS = "https";
    private static SSLConnectionSocketFactory sslsf = null;
    private static PoolingHttpClientConnectionManager cm = null;
    private static SSLContextBuilder builder = null;
    static {
        try {
            builder = new SSLContextBuilder();
            // 全部信任 不做身份鉴定
            builder.loadTrustMaterial(null, new TrustStrategy() {
                @Override
                public boolean isTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException {
                    return true;
                }
            });
            sslsf = new SSLConnectionSocketFactory(builder.build(), new String[] { "SSLv2Hello", "SSLv3", "TLSv1", "TLSv1.2" }, null, NoopHostnameVerifier.INSTANCE);
            Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory> create().register(HTTP, new PlainConnectionSocketFactory()).register(HTTPS, sslsf).build();
            cm = new PoolingHttpClientConnectionManager(registry);
            cm.setMaxTotal(200);// max connection
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * httpClient post请求
     * 
     * @param url
     *            请求url
     * @param header
     *            头部信息
     * @param param
     *            请求参数 form提交适用
     * @param entity
     *            请求实体 json/xml提交适用
     * @return 可能为空 需要处理
     * @throws Exception
     * 
     */
    public static String doGet(String url) throws Exception {
        String result = "";
        CloseableHttpClient httpClient = null;
        try {
            httpClient = getHttpClient();
            HttpGet httpGet = new HttpGet(url);
            RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(30000).setConnectTimeout(30000).build();// 设置请求和传输超时时间
            httpGet.setConfig(requestConfig);
            HttpResponse httpResponse = httpClient.execute(httpGet);
            int statusCode = httpResponse.getStatusLine().getStatusCode();
            if (statusCode == HttpStatus.SC_OK) {
                HttpEntity resEntity = httpResponse.getEntity();
                result = EntityUtils.toString(resEntity);
            } else {
                readHttpResponse(httpResponse);
            }
        } catch (Exception e) {
            throw e;
        } finally {
            if (httpClient != null) {
                httpClient.close();
            }
        }
        return result;
    }

    /**
     * httpClient post请求
     * 
     * @param url
     *            请求url
     * @param header
     *            头部信息
     * @param param
     *            请求参数 form提交适用
     * @param entity
     *            请求实体 json/xml提交适用
     * @return 可能为空 需要处理
     * @throws Exception
     * 
     */
    public static String doPost(String url, Map<String, String> header, Map<String, String> param, HttpEntity entity) throws Exception {
        String result = "";
        CloseableHttpClient httpClient = null;
        try {
            httpClient = getHttpClient();
            HttpPost httpPost = new HttpPost(url);
            // 设置头信息
            if (MapUtils.isNotEmpty(header)) {
                for (Map.Entry<String, String> entry : header.entrySet()) {
                    httpPost.addHeader(entry.getKey(), entry.getValue());
                }
            }
            // 设置请求参数
            if (MapUtils.isNotEmpty(param)) {
                List<NameValuePair> formparams = new ArrayList<NameValuePair>();
                for (Map.Entry<String, String> entry : param.entrySet()) {
                    // 给参数赋值
                    formparams.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
                }
                UrlEncodedFormEntity urlEncodedFormEntity = new UrlEncodedFormEntity(formparams, Consts.UTF_8);
                httpPost.setEntity(urlEncodedFormEntity);
            }
            // 设置实体 优先级高
            if (entity != null) {
                httpPost.setEntity(entity);
            }
            HttpGet httpGet = new HttpGet(url);
            HttpResponse httpResponse = httpClient.execute(httpGet);
            int statusCode = httpResponse.getStatusLine().getStatusCode();
            if (statusCode == HttpStatus.SC_OK) {
                HttpEntity resEntity = httpResponse.getEntity();
                result = EntityUtils.toString(resEntity);
            } else {
                readHttpResponse(httpResponse);
            }
        } catch (Exception e) {
            throw e;
        } finally {
            if (httpClient != null) {
                httpClient.close();
            }
        }
        return result;
    }

    public static CloseableHttpClient getHttpClient() throws Exception {
        CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(sslsf).setConnectionManager(cm).setConnectionManagerShared(true).build();

        return httpClient;
    }

    public static String readHttpResponse(HttpResponse httpResponse) throws ParseException, IOException {
        StringBuilder builder = new StringBuilder();
        // 获取响应消息实体
        HttpEntity entity = httpResponse.getEntity();
        // 响应状态
        builder.append("status:" + httpResponse.getStatusLine());
        builder.append("headers:");
        HeaderIterator iterator = httpResponse.headerIterator();
        while (iterator.hasNext()) {
            builder.append("	" + iterator.next());
        }
        // 判断响应实体是否为空
        if (entity != null) {
            String responseString = EntityUtils.toString(entity);
            builder.append("response length:" + responseString.length());
            builder.append("response content:" + responseString.replace("
", ""));
        }
        return builder.toString();
    }
}

　　paypal支付按钮（standardPayment.html）代码如下：

<html>
<head>
<meta charset="UTF-8" />
<title>Insert title here</title>
</head>
<body>
    <form action="https://www.sandbox.paypal.com/cgi-bin/webscr" method="post" target="_top">
    <input type="hidden" name="cmd" value="_xclick"><%--支付类型--%>
    <input type="hidden" name="business" value="sb-ux7pa3602231@business.example.com"><%--商家账号--%>
    <input type="hidden" name="hosted_button_id" value="CWA2QSSG7CDBA"><%--按钮id，由paypal生成--%>
    <input TYPE="hidden" name="charset" value="utf-8"><%--编码--%>
    <input type="hidden" name="invoice" value="ABC123"><%--自定义订单编号--%>
    <input type="hidden" name="item_name" value="Server服务开通"><%--商品名称--%>
    <input type="hidden" name="item_number" value="1"><%--商品数量--%>
    <input type="hidden" name="amount" value="5.95"><%--商品价格--%>
    <input type="hidden" name="currency_code" value="USD"><%--货币--%>
    <input type="hidden" name="return" value=""><%--支付成功（PDT地址）--%>
    <input type="hidden" name="cancel_return" value=""><%--支付失败页面--%>
    <%-- <input type="hidden" name="notify_url" value="">回调路径（IPN地址） --%>
    <input type='hidden' name="no_shipping" value="1"><%--不要求客户提供收货地址--%>
    <input type="hidden" name="rm" value="2"><%--return有地址的话，必须指定这个参数--%>
    <input type="hidden" name="no_note" value="老子不想付款啊。。。。"><%--付款说明--%>
    <input type="hidden" name="image_url" value="https://www.paypal.com/zh_XC/i/btn/btn_buynow_SM.gif"><%--图片--%>
    <input type="hidden" name="custom" value="admin"><%--自定义变量传递服务器需要信息--%>
    <input type="image" src="https://www.sandbox.paypal.com/zh_XC/i/btn/btn_buynow_SM.gif" border="0" name="submit" alt="PayPal——最安全便捷的在线支付方式！">
    <img alt="" border="0" src="https://www.sandbox.paypal.com/zh_XC/i/scr/pixel.gif" width="1" height="1">
</form>
</body>
</html>

　　cancel.html代码如下：

<html>
<head>
<meta charset="UTF-8" />
<title>Insert title here</title>
</head>
<body>
    <h1>用户取消支付...</h1>
</body>
</html>

　　success.html代码如下：

<html>
<head>
<meta charset="UTF-8" />
<title>Insert title here</title>
</head>
<body>
    <h1>用户支付成功</h1>
</body>
</html>

　　failure.html代码如下：

<html>
<head>
<meta charset="UTF-8" />
<title>Insert title here</title>
</head>
<body>
    <h1>用户支付失败</h1>
</body>
</html>