一、开发前准备
1:申请微信公众号 和 微信小程序,这是两个不同的东西,都需要单独申请、不同的帐号;
2:微信公众号需要开通微信卡券的功能;
3:在微信公众号里面去绑定小程序;
4:申请微信开放平台,并将微信公众号 和 微信小程序绑定到该开放平台。(注:绑定到开发平台下的作用只是为了获取unionid,因为同一用户在 公众号 和 小程序下获得的openid是不一样的,如果公众号 和 小程序都需要领取卡券,则最好通过unionid来跟踪用户;如果你只是开发微信小程序的领取卡券,则完全可以忽略第4点,博主本人也没有去绑定到微信开放平台,感觉步骤好多,特别麻烦!)
二、开始开发
1:获取微信卡券
https://mp.weixin.qq.com/wiki?t=resource/res_main&id=mp1451025272
这边可以直接通过微信公众号提供的接口获取或者创建微信的卡券,此处不过多介绍,只是提一下这边要获取的access_token,网址如下https://mp.weixin.qq.com/wiki?t=resource/res_main&id=mp1421140183,代码直接如下:
private static String grantType = "client_credential";
public static String appId = ""; //微信公众号appid
public static String secret = ""; //微信公众号密钥
public static AccessToken token = null; //微信公众号的accessToken对象,由于请求次数有限制,这里使用全局静态变量保存起来
public static AccessToken getToken() throws WeixinException, JsonParseException, JsonMappingException, IOException{
if(token == null || token.getExpires_in() < System.currentTimeMillis()){
//拼接参数
String param = "?grant_type=" + grantType + "&appid=" + appId + "&secret=" + secret;
//创建请求对象
HttpsClient http = new HttpsClient();
//调用获取access_token接口
Response res = http.get("https://api.weixin.qq.com/cgi-bin/token" + param);
System.out.println(res.asString());
ObjectMapper mapper = new ObjectMapper();
token = mapper.readValue(res.asString(),AccessToken.class);
}
return token;
}
其中需要jackson和weixin4j的jar包,比较普遍,请自行下载;而AccessToken对象也比较简单,就errcode、errmsg、access_token、expires_in这四个参数,比较简单,在文章结尾贴代码
2:升级微信卡券
其实这个步骤也可以省略,升级微信卡券的目的是可以直接从微信卡券跳转到对应的小程序,博主就偷懒了,直接跳过了这个步骤;
不过升级卡券也比较简单,就是调用调用微信公众号的更改微信卡券接口(URL:https://api.weixin.qq.com/card/update?access_token=TOKEN),添加几个字段,可以参考微信官方文档3.1,链接如下:https://mp.weixin.qq.com/cgi-bin/announce?action=getannouncement&key=1490190158&version=1&lang=zh_CN&platform=2
3:领取卡券
3.1:先获取openId
小程序端代码,通过调用wx.login获取code,再调用https://api.weixin.qq.com/sns/jscode2session接口获取openid,博主看到很多例子是直接从小程序端调用这个接口,但我事实中发现是行不通的,因为这个域名无法添加到小程序的request合法域名中,微信给的说明是不要在前端调用这个接口,需要通过后台,那没办法喽
wx.login({
success: function (res) {
var service_url = 'https://???/???/weixin/api/login?code=' + res.code;//需要将服务器域名添加到小程序的request合法域名中,而且必须是https开头
wx.request({
url: l,
data: {},
method: 'GET',
success: function (res) {
console.log(res);
if (res.data != null && res.data != undefined && res.data != '') {
wx.setStorageSync("openid", res.data.openid);//将获取的openid存到缓存中
}
}
});
}
});
后端java代码
/**
* 小程序后台登录,向微信平台发送获取access_token请求,并返回openId
* @param code
* @return 用户凭证
* @throws WeixinException
* @throws IOException
* @throws JsonMappingException
* @throws JsonParseException
*/
@RequestMapping("login")
@ResponseBody
public Map<String, Object> login(String code, HttpServletRequest request) throws WeixinException, JsonParseException, JsonMappingException, IOException {
if (code == null || code.equals("")) {
throw new WeixinException("invalid null, code is null.");
}
Map<String, Object> ret = new HashMap<String, Object>();
//拼接参数
String param = "?grant_type=" + grant_type + "&appid=" + appid + "&secret=" + secret + "&js_code=" + code;
System.out.println("https://api.weixin.qq.com/sns/jscode2session" + param);
//创建请求对象
HttpsClient http = new HttpsClient();
//调用获取access_token接口
Response res = http.get("https://api.weixin.qq.com/sns/jscode2session" + param);
//根据请求结果判定,是否验证成功
JSONObject jsonObj = res.asJSONObject();
if (jsonObj != null) {
Object errcode = jsonObj.get("errcode");
if (errcode != null) {
//返回异常信息
throw new WeixinException(getCause(Integer.parseInt(errcode.toString())));
}
ObjectMapper mapper = new ObjectMapper();
OAuthJsToken oauthJsToken = mapper.readValue(jsonObj.toJSONString(),OAuthJsToken.class);
ret.put("openid", oauthJsToken.getOpenid());
}
return ret;
}
其中OAuthJsToken对象的字段为:openid、expires_in、session_key(会话密钥) ,在文章结尾贴代码;
3.2:生成领取卡券的签名,并调用wx.addCard方法领取卡券
这边写贴java后端代码
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
/**
* @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("getCardSign")
@ResponseBody
public Map<String, String> getCardSign(String cardId) throws WeixinException, JsonParseException, JsonMappingException, IOException{
Map<String, String> ret = new HashMap<String, 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 = OpenApi.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
//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(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;
}
/**
* @Description: 生成卡券需要的签名并返回参数
* @param api_ticket:
* @param cardId:需要领取的卡券的cardId
* @return
*/
public static Map<String, String> sign(String api_ticket, String cardId) {
Map<String, String> ret = new HashMap<String, String>();
String nonce_str = create_nonce_str();
String timestamp = create_timestamp();
String signature = "";
String param[] = new String[4];
param[0] = nonce_str;
param[1] = timestamp;
param[2] = api_ticket;
param[3] = cardId;
Arrays.sort(param);//对参数的value值进行字符串的字典序排序
StringBuilder sb = new StringBuilder();
for(String b : param){
sb.append(b);
}
System.out.println(sb);
//对上面拼接的字符串进行sha1加密,得到signature
try{
MessageDigest crypt = MessageDigest.getInstance("SHA-1");
crypt.reset();
crypt.update(sb.toString().getBytes("UTF-8"));
signature = byteToHex(crypt.digest());
}catch (NoSuchAlgorithmException e){
e.printStackTrace();
}catch (UnsupportedEncodingException e){
e.printStackTrace();
}
//返回领取卡券需要的参数,其中nonceStr和timestamp必须和签名中的保持一致
ret.put("card_id", cardId);
ret.put("api_ticket", api_ticket);
ret.put("nonceStr", nonce_str);
ret.put("timestamp", timestamp);
ret.put("signature", signature);
return ret;
}
其中ApiTicket对象的属性有:errcode、errmsg、ticket、expires_in,在文章结尾贴出该代码
再贴小程序端代码
var that = this;
var service_url = 'https://???/???/weixin/api/getCardSign?cardId=' + cardId;//需要将服务器域名添加到小程序的request合法域名中,而且必须是https开头
wx.request({
url: service_url,
data: {},
method: 'GET',
success: function (res) {
console.log(res);
wx.addCard({
cardList: [{
cardId: that.data.cardId,
cardExt: '{"code":"","openid":"","timestamp":' + res.data.timestamp + ',"nonce_str":"' + res.data.nonceStr + '","signature":"' + res.data.signature + '"}'
}],//这里需要注意的是cardExt参数的value值是 String类型,不要使用对象发送;另外openid如果在创建优惠券的时候没有指定,则这边为空,千万不要填写当前用户的openid
success: function (result) {
console.log(res);
wx.showToast({
title: '领取成功',
icon: 'success',
duration: 2000
});
},
fail: function (res) {
console.log('领取失败');
console.log(res);
}
})
}
});
ok,如果领取成功,可以直接到微信卡包里面查看。下面贴出AccessToken、ApiTicket、OAuthJsToken的java模型代码
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;
}
}
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
}
}
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
}
}
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;
}
}
---------------------
作者:zhourenfei17
来源:CSDN
原文:https://blog.csdn.net/zhourenfei17/article/details/77714600?utm_source=copy
版权声明:本文为博主原创文章,转载请附上博文链接!