html5调用微信支付宝接口,微信支付-公众号支付-JSAPI调用（V2——Java）

import com.alibaba.fastjson.JSON;

import com.alibaba.fastjson.JSONObject;

import ***********************.WeChatConst;//一些常量

import org.apache.http.HttpResponse;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.entity.StringEntity;

import org.apache.http.impl.client.DefaultHttpClient;

import org.apache.http.util.EntityUtils;

import java.io.*;

import java.nio.charset.Charset;

import java.util.HashMap;

import java.util.Map;

import java.util.Random;

/**

* Created by Arthur on 2015/11/10 16:45.

*/

public class WeChatUtil {

/**

* 通过Code 获取用户 openid 和 access_token

* @param code

* @return

* @throws IOException

*/

public static Map getOpenIdByCode(String code) throws IOException {

/**

* 设置访问路径

*/

HttpPost httppost = new HttpPost("https://api.weixin.qq.com/sns/oauth2/access_token");

/**

* 组装请求参数

*/

String reqEntityStr = "appid=APPID&secret=SECRET&code=CODE&grant_type=authorization_code";

reqEntityStr = reqEntityStr.replace("APPID", WeChatConst.APPID);

reqEntityStr = reqEntityStr.replace("SECRET", WeChatConst.APP_SECRET);

reqEntityStr = reqEntityStr.replace("CODE", code);

StringEntity reqEntity = new StringEntity(reqEntityStr);

/**

* 设置浏览器

*/

DefaultHttpClient httpclient = new DefaultHttpClient();

/**

* 设置参数

*/

httppost.setEntity(reqEntity);

/**

* 发起请求

*/

HttpResponse response = httpclient.execute(httppost);

/**

* 获得请求内容

*/

String strResult = EntityUtils.toString(response.getEntity(), Charset.forName("utf-8"));

/**

* 分析内容

*/

JSONObject jsonObject = (JSONObject) JSON.parse(strResult);

Map map = new HashMap<>();

map.put("openid",jsonObject.get("openid"));

map.put("access_token",jsonObject.get("access_token"));

map.put("refresh_token",jsonObject.get("refresh_token"));

return map;

}

/**

* 统一下单

* 获得PrePayId

* @param body  商品或支付单简要描述

* @param out_trade_no 商户系统内部的订单号,32个字符内、可包含字母

* @param total_fee  订单总金额，单位为分

* @param IP    APP和网页支付提交用户端ip

* @param notify_url 接收微信支付异步通知回调地址

* @param openid 用户openId

* @throws IOException

*/

public static String unifiedorder(String body,String out_trade_no,Integer total_fee,String IP,String notify_url,String openid)throws IOException {

/**

* 设置访问路径

*/

HttpPost httppost = new HttpPost("https://api.mch.weixin.qq.com/pay/unifiedorder");

/**

* 组装请求参数

* 按照ASCII排序

*/

String reqEntityStr = "appid=APPID" +

"&body=BODY" +

"&mch_id=MCH_ID" +

"&nonce_str=NONCE_STR" +

"&notify_url=NOTIFY_URL" +

"&openid=OPENID" +

"&out_trade_no=OUT_TRADE_NO" +

"&spbill_create_ip=IP" +

"&total_fee=TOTAL_FEE" +

"&trade_type=TRADE_TYPE"

;//这个字段是用于之后MD5加密的，字段要按照ascii码顺序排序

/**

* 设置数据

*/

String nonce_str = getNonceStr().toUpperCase();//随机数据

reqEntityStr = reqEntityStr.replace("APPID", WeChatConst.APPID);

reqEntityStr = reqEntityStr.replace("MCH_ID", WeChatConst.MCH_ID);

reqEntityStr = reqEntityStr.replace("NONCE_STR", nonce_str);

reqEntityStr = reqEntityStr.replace("BODY", body);

reqEntityStr = reqEntityStr.replace("OUT_TRADE_NO", out_trade_no);

reqEntityStr = reqEntityStr.replace("TOTAL_FEE", total_fee.toString());

reqEntityStr = reqEntityStr.replace("IP", IP);

reqEntityStr = reqEntityStr.replace("NOTIFY_URL", notify_url);

reqEntityStr = reqEntityStr.replace("TRADE_TYPE", WeChatConst.TRADE_TYPE);

reqEntityStr = reqEntityStr.replace("OPENID", openid);

/**

* 生成sign的数据

*/

String sign = reqEntityStr + "&key="+WeChatConst.KEY;

sign = MD5Util.MD5(sign).toUpperCase();

/**

* 组装XML

*/

StringBuilder sb = new StringBuilder("");

sb.append("");

setXmlKV(sb,"appid",WeChatConst.APPID);

setXmlKV(sb,"body",body);

setXmlKV(sb,"mch_id",WeChatConst.MCH_ID);

setXmlKV(sb,"nonce_str",nonce_str);

setXmlKV(sb,"notify_url",notify_url);

setXmlKV(sb,"openid",openid);

setXmlKV(sb,"out_trade_no",out_trade_no);

setXmlKV(sb,"spbill_create_ip",IP);

setXmlKV(sb,"total_fee",total_fee.toString());

setXmlKV(sb,"trade_type",WeChatConst.TRADE_TYPE);

setXmlKV(sb,"sign",sign);

sb.append("");

//        reqEntityStr = reqEntityStr.replace("sign", sign);

StringEntity reqEntity = new StringEntity(new String (sb.toString().getBytes("UTF-8"),"ISO8859-1"));//这个处理是为了防止传中文的时候出现签名错误

httppost.setEntity(reqEntity);

DefaultHttpClient httpclient = new DefaultHttpClient();

HttpResponse response = httpclient.execute(httppost);

String strResult = EntityUtils.toString(response.getEntity(), Charset.forName("utf-8"));

//        System.out.println(strResult);

return getPrePayId(strResult);

}

/**

* 获得32位随机字符串

* @return

*/

public static String getNonceStr(){

String str = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

StringBuilder sb = new StringBuilder();

Random rd = new Random();

for(int i = 0 ; i < 32 ; i ++ ){

sb.append(str.charAt(rd.nextInt(str.length())));

}

return sb.toString();

}

/**

* 插入XML标签

* @param sb

* @param Key

* @param value

* @return

*/

public static StringBuilder setXmlKV(StringBuilder sb,String Key,String value){

sb.append("

sb.append(Key);

sb.append(">");

sb.append(value);

sb.append("");

sb.append(Key);

sb.append(">");

return sb;

}

/**

* 解析XML  获得 PrePayId

* @param xml

* @return

*/

public static String getPrePayId(String xml){

int start = xml.indexOf("");

int end = xml.indexOf("");

if(start < 0 && end < 0){

return null;

}

return xml.substring(start + "".length(),end)

.replace("","");

}

}