支付宝APP支付之Java后台生成签名具体步骤

   /**    *支付宝支付    * @param orderId 订单编号    * @param actualPay 实际支付金额    * @return    */ private String getOrderInfoByAliPay(String orderId,float actualPay) {

      //回调页面      String ali_call_back_url = propertiesService.ALI_CALL_BACK_URL;      String seller_id = propertiesService.SELLER_ID;//商户编号      String[] parameters={            "service=\"mobile.securitypay.pay\"",//固定值（手机快捷支付）            "partner=\"2088421544444\"",//合作身份者ID（16位）

            "_input_charset=\"utf-8\"",            "notify_url=\""+ali_call_back_url+"\"",//通知地址            "out_trade_no=\""+orderId+"\"",//商户内部订单号            "subject=\"测试\"",//测试            "payment_type=\"1\"",//固定值            "seller_id=\""+seller_id+"\"",//账户邮箱           "total_fee=\""+"0.01"+"\"",//支付金额（元）

            "body=\"订单说明\"",//订单说明            

            "it_b_pay=\"30m\""（订单过期时间 30分钟过期无效）      };      String signOrderUrl = signAllString(parameters);      return signOrderUrl;   }

/** * 支付宝签名 * @param array * @return */private String signAllString(String [] array){   StringBuffer sb = new StringBuffer("");   for (int i = 0; i < array.length; i++) {      if(i==(array.length-1)){         sb.append(array[i]);      }else{         sb.append(array[i]+"&");      }   }   System.out.println(sb.toString());   String sign = "";   try {      sign = URLEncoder.encode(RSA.sign(sb.toString(), AlipayConfig.private_key, "utf-8"), "utf-8");//private_key私钥   } catch (UnsupportedEncodingException e) {      e.printStackTrace();   }   sb.append("&sign=\""+sign+"\"&");   sb.append("sign_type=\"RSA\"");   return sb.toString();}

package com.alipay.sign;

import javax.crypto.Cipher;import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.InputStream;import java.security.KeyFactory;import java.security.PrivateKey;import java.security.PublicKey;import java.security.spec.PKCS8EncodedKeySpec;import java.security.spec.X509EncodedKeySpec;

public class RSA{

   public static final String  SIGN_ALGORITHMS = "SHA1WithRSA";

   /**   * RSA签名   * @param content 待签名数据   * @param privateKey 商户私钥   * @param input_charset 编码格式   * @return 签名值   */   public static String sign(String content, String privateKey, String input_charset)   {        try         {         byte[] decode = Base64.decode(privateKey);         PKCS8EncodedKeySpec priPKCS8   = new PKCS8EncodedKeySpec(decode );           KeyFactory keyf= KeyFactory.getInstance("RSA");           PrivateKey priKey= keyf.generatePrivate(priPKCS8);

            java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS);

            signature.initSign(priKey);            signature.update( content.getBytes(input_charset) );

            byte[] signed = signature.sign();

            return Base64.encode(signed);        }        catch (Exception e)         {           e.printStackTrace();        }

        return null;    }

   /**   * RSA验签名检查   * @param content 待签名数据   * @param sign 签名值   * @param ali_public_key 支付宝公钥   * @param input_charset 编码格式   * @return 布尔值   */   public static boolean verify(String content, String sign, String ali_public_key, String input_charset)   {      try       {         KeyFactory keyFactory = KeyFactory.getInstance("RSA");           byte[] encodedKey = Base64.decode(ali_public_key);           PublicKey pubKey = keyFactory.generatePublic(new X509EncodedKeySpec(encodedKey));         java.security.Signature signature = java.security.Signature         .getInstance(SIGN_ALGORITHMS);

         signature.initVerify(pubKey);         signature.update( content.getBytes(input_charset) );

         boolean bverify = signature.verify( Base64.decode(sign) );         return bverify;

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

      return false;   }

   /**   * 解密   * @param content 密文   * @param private_key 商户私钥   * @param input_charset 编码格式   * @return 解密后的字符串   */   public static String decrypt(String content, String private_key, String input_charset) throws Exception {        PrivateKey prikey = getPrivateKey(private_key);

        Cipher cipher = Cipher.getInstance("RSA");        cipher.init(Cipher.DECRYPT_MODE, prikey);

        InputStream ins = new ByteArrayInputStream(Base64.decode(content));        ByteArrayOutputStream writer = new ByteArrayOutputStream();        //rsa解密的字节大小最多是128，将需要解密的内容，按128位拆开解密        byte[] buf = new byte[128];        int bufl;

        while ((bufl = ins.read(buf)) != -1) {            byte[] block = null;

            if (buf.length == bufl) {                block = buf;            } else {                block = new byte[bufl];                for (int i = 0; i < bufl; i++) {                    block[i] = buf[i];                }            }

            writer.write(cipher.doFinal(block));        }

        return new String(writer.toByteArray(), input_charset);    }

   /**   * 得到私钥   * @param key 密钥字符串（经过base64编码）   * @throws Exception   */   public static PrivateKey getPrivateKey(String key) throws Exception {

      byte[] keyBytes;

      keyBytes = Base64.decode(key);

      PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);

      KeyFactory keyFactory = KeyFactory.getInstance("RSA");

      PrivateKey privateKey = keyFactory.generatePrivate(keySpec);

      return privateKey;   }}

支付宝参数里面为什么要进行转义？主要是因为返回给移动的参数结果是springmvc进行返回的给移动端时，会认为"为结束，所以需要\"进行转义！