首先在公众号后台获取卡券id，获取公众号的appid和accessToken，opendid（小程序端）：小程序登陆时获取存起来
导入weixin4j包
java代码，小程序略
package com.enation.app.shop.wechat.controller;import java.io.IOException;import java.io.UnsupportedEncodingException;import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;import java.util.Arrays;import java.util.Date;import java.util.HashMap;import java.util.Map;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.ResponseBody;import org.weixin4j.WeixinException;import org.weixin4j.http.HttpsClient;import org.weixin4j.http.Response;import com.enation.app.shop.wechat.model.AccessToken;import com.enation.app.shop.wechat.model.ApiTicket;import com.enation.app.shop.wechat.model.WeixinSignature;import com.enation.app.shop.wechat.utils.WeChatCart;import com.fasterxml.jackson.core.JsonParseException;import com.fasterxml.jackson.databind.JsonMappingException;import com.fasterxml.jackson.databind.ObjectMapper;@Controller@RequestMapping("/")public class WechatGetTicket { public static ApiTicket ticket = null;//使用全局静态变量存储ApiTicket对象，当然如果使用缓存框架保存当然更好，这边只是做一个简单示例 private final static String string = "0123456789"; final private static char[] chars = string.toCharArray();/** * @Description: 获取领取卡券获取签名等参数 * @param cardId：需要领取的卡券的cardId * @return * @throws WeixinException * @throws JsonParseException * @throws JsonMappingException * @throws IOException */@RequestMapping("/")@ResponseBodypublic MapString, String getCardSign(String cardId) throws WeixinException, JsonParseException, JsonMappingException, IOException{MapString, String ret = new HashMapString, String();//先要获取api_ticket，由于请求api_ticket的接口访问有次数限制，所以最好将获得到的api_ticket保存到缓存中，这边做法比较简单，直接使用的静态变量if(ticket == null || ticket.getExpires_in() System.currentTimeMillis()){//创建请求对象 HttpsClient http = new HttpsClient(); ObjectMapper mapper = new ObjectMapper(); AccessToken token = WeChatCart.getToken();//这里获取的token就是最上方代码保存的微信公众号全局静态变量token System.out.println(token.getErrcode()); //通过access_token调用获取api_ticket接口 Response res = http.get("https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=" + token.getAccess_token() + "&type=wx_card"); System.out.println("api_ticket:==========="+res.asString()); ticket = mapper.readValue(res.asString(), ApiTicket.class); } ret = sign(ticket.getTicket(), cardId);//生成领取卡券需要的签名，并返回相关的参数 for (Map.Entry entry : ret.entrySet()) { System.out.println(entry.getKey() + ", " + entry.getValue()); } return ret;}/** * @param api_ticket： * @param cardId：需要领取的卡券的cardId * @return * @Description: 生成卡券需要的签名并返回参数 */public static MapString, String sign(String api_ticket, String cardId) { MapString, String ret = new HashMapString, String(); String nonce_str = create_nonce_str(); String timestamp = create_timestamp(); String signature = ""; WeixinSignature signatures = new WeixinSignature(api_ticket, timestamp, cardId, nonce_str); ret.put("card_id", cardId); ret.put("api_ticket", api_ticket); ret.put("nonceStr", nonce_str); ret.put("timestamp", timestamp); ret.put("signature", signatures.sign()); return ret;}/** * 返回时间戳（秒） * @return */private static String create_timestamp() { return String.valueOf(new Date().getTime() / 1000);}/** * 返回随机字符串 * @return */private static String create_nonce_str() { String nonce = new String(); for (int i = 0; i 32; i++) { int rannum = (int) (Math.random() * 1000) % (chars.length); nonce += chars[rannum]; } return nonce;}/** * Convert byte[] to hex string * @param src byte[] data * @return hex string */ public static String bytesToHexString(byte[] src) { StringBuilder stringBuilder = new StringBuilder(""); if (src == null || src.length = 0) { return null; } for (int i = 0; i src.length; i++) { int v = src[i] & 0xFF; String hv = Integer.toHexString(v); if (hv.length() 2) { stringBuilder.append(0); } stringBuilder.append(hv); } return stringBuilder.toString(); }}package com.enation.app.shop.wechat.base;public class BaseResponse {private int errcode;private String errmsg;public int getErrcode() {return errcode;}public void setErrcode(int errcode) {this.errcode = errcode;}public String getErrmsg() {return errmsg;}public void setErrmsg(String errmsg) {this.errmsg = errmsg;}}package com.enation.app.shop.wechat.model;import com.enation.app.shop.wechat.base.BaseResponse;public class AccessToken extends BaseResponse{private String access_token;private long expires_in;public String getAccess_token() {return access_token;}public void setAccess_token(String access_token) {this.access_token = access_token;}public long getExpires_in() {return expires_in;}public void setExpires_in(long expires_in) {this.expires_in = System.currentTimeMillis() + (expires_in - 100) * 1000;//原expires_in是有效时长，比如：7200，现改为过期的时间戳}}package com.enation.app.shop.wechat.model;import com.enation.app.shop.wechat.base.BaseResponse;public class ApiTicket extends BaseResponse{private String ticket;private long expires_in;public String getTicket() {return ticket;}public void setTicket(String ticket) {this.ticket = ticket;}public long getExpires_in() {return expires_in;}public void setExpires_in(long expires_in) {this.expires_in = System.currentTimeMillis() + (expires_in - 100) * 1000;//原expires_in是有效时长，比如：7200，现改为过期的时间戳}}package com.enation.app.shop.wechat.model;public class OAuthJsToken {private String openid;//用户唯一标识private int expires_in = 7200; //凭证有效时间，单位：秒private String session_key;//会话密匙private long exprexpiredTime;//过期时间public String getOpenid() {return openid;}public void setOpenid(String openid) {this.openid = openid;}public int getExpires_in() {return expires_in;}public void setExpires_in(int expires_in) {this.expires_in = expires_in;this.exprexpiredTime = System.currentTimeMillis() + expires_in * 1000;}public String getSession_key() {return session_key;}public void setSession_key(String session_key) {this.session_key = session_key;}public long getExprexpiredTime() {return exprexpiredTime;}public void setExprexpiredTime(long exprexpiredTime) {this.exprexpiredTime = exprexpiredTime;}/** * 判断用户凭证是否过期 * * @return 过期返回 true,否则返回false */ public boolean isExprexpired() { return System.currentTimeMillis() = this.exprexpiredTime; }}package com.enation.app.shop.wechat.model;import java.util.Arrays;import com.enation.app.shop.wechat.utils.GetSha1;public class WeixinSignature{ private String api_ticket; private String timestamp; private String card_id; private String nonce_str; public WeixinSignature(String api_ticket, String timestamp, String card_id, String nonce_str) { this.api_ticket = api_ticket; this.timestamp = timestamp; this.card_id = card_id; this.nonce_str = nonce_str; } public String sign() { String[] str = { this.api_ticket, this.timestamp, this.card_id, this.nonce_str }; System.out.println("加密调用的加密参数" + str.toString()); Arrays.sort(str); String string = new String(); for (int i = 0; i 4; i++) { string = string + str[i]; } String signature = null; signature = GetSha1.getSha1(string); return signature; }}package com.enation.app.shop.wechat.utils;import java.security.MessageDigest;public class GetSha1{ public static String getSha1(String str) { if ((str == null) || (str.length() == 0)) { return null; } char[] hexDigits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; try { MessageDigest mdTemp = MessageDigest.getInstance("SHA1"); mdTemp.update(str.getBytes("UTF-8")); byte[] md = mdTemp.digest(); int j = md.length; char[] buf = new char[j * 2]; int k = 0; for (int i = 0; i j; i++) { byte byte0 = md[i]; buf[(k++)] = hexDigits[(byte0 4 & 0xF)]; buf[(k++)] = hexDigits[(byte0 & 0xF)]; } return new String(buf); } catch (Exception e) { } return null; }}小程序
