微信登录获取 OpenId

WechatController.java

package com.besfim.wxpay.controller;

import com.alibaba.fastjson.JSONObject;
import com.besfim.wxpay.utils.HttpUtils;
import com.besfim.wxpay.utils.SHA1;
import com.besfim.wxpay.utils.obj.ResJson;

import org.apache.http.HttpException;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

import java.io.IOException;
import java.net.URLEncoder;

import javax.servlet.http.HttpServletRequest;

import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

/**
 *
 * 微信公众号开发，获取 openid 之类的
 *
 * 微信公众号鉴权如下
 *
 *  - 访问某个 login 接口（服务器提供），这是个 URL_A
 *  - 该接口负责拼接出一个 wx 的 url，让用户跳转，这个 url 带有一个跳转的 URL_B
 *  - 用户跳转到 wx 的 url，这个 url 会在微信手机端提示用户鉴权，
 *      用户允许之后，会跳转到 URL_B?code={CODE}
 *  - URL_B 是一个接口，负责接受 CODE 参数，然后将 CODE 参数带上 appid 和 secret 等
 *      向微信官方服务器换取该用户的 OpenId，至此该用户完成登录
 *
 * Created by Ericwyn on 19-2-18.
 */
@Controller
public class WechatController {

    //    // 正式微信公众号 id 和 secret
    private static final String appid="openid";
    private static final String secret="secret";
    //    //正式部署时候的域名,关系到能够成功跳转微信获取 openid 的接口
    private static final String runDomain = "https://wx.meetwhy.com";

    // 一个中途转跳的 URL，用户在允许微信鉴权之后，跳转到 URL?code=CODE
    private static final String URI_REDIRECT = "/user/wx/code";

    private OkHttpClient httpClient = HttpUtils.getClient();

    /**
     * 通过这个地址转跳去微信官方地址，以获取微信登录的 code
     * 并在之后跳转到正式登录接口
     *
     * @return
     */
    @RequestMapping("/user/wx/login")
    public String redirectToWechat(){
        return "redirect:https://open.weixin.qq.com/connect/oauth2/authorize?appid="+appid+"&redirect_uri="+ URLEncoder.encode(runDomain+ URI_REDIRECT)+"&response_type=code&scope=snsapi_base&state=STATE#wechat_redirect";
    }


    /**
     * 获取 Code 之后就访问这个地址
     *
     *
     * @param request
     * @return
     * @throws HttpException
     * @throws IOException
     */
    @RequestMapping(value = URI_REDIRECT)
    public String wexinRegister(HttpServletRequest request) throws IOException {
        System.out.println("收到微信注册请求");
        String openid ;
        //用户微信登录获取openid
        String code=(String) request.getParameter("code");
        System.out.println(" code 是 "+code);
        if(code==null){
            return "redirect:ErrorPageInWechatLogin.html";
        }
        Request wxRequest = new Request.Builder()
                .url(String.format("https://api.weixin.qq.com/sns/oauth2/access_token?appid=%s&secret=%s&code=%s&grant_type=authorization_code", appid,secret,code))
                .get()
                .build();
        Response response = httpClient.newCall(wxRequest).execute();
        if (response.isSuccessful()){
            String respText = response.body().string();
            JSONObject json = JSONObject.parseObject(respText);
            openid = json.getString("openid");
            return ("redirect:"+runDomain+"/wx.html?openid="+ openid);
        }else {
            return ("redirect:"+runDomain+"/wx.html?openid=获取id失败");
        }
    }

    // 获取jssdk 认证所需 appid，timestamp，noncestr，signature等信息，需要后端小伙伴配合

    @RequestMapping(value = "/user/wx/jssdk",method = RequestMethod.POST)
    @ResponseBody
    public ResJson registerJsSdk(@RequestParam("url") String url){
        JsApiRegistResJson json = getJsApiRegist(url);
        if (json == null){
            return ResJson.failJson(-1, "获取失败", null);
        }
        return ResJson.successJson("获取成功", json);
    }

    private class JsTicket {
        String ticket;
        Long createTime;
    }
    // 应该写在Server 里面的获取 Js ticket 的
//    private HashMap<String, JsTicket> jsTicketMap = new HashMap<>();
    // 获取 JsTicket，每个 url 对应的每个 ticket 有 7200s 的有效时间
//    private Long lastGetTime=0L;

    private String jsTicket = null;
    private Long lastGetTime=0L;
    private String accessToken = null;
    public class JsApiRegistResJson {
        private String appid;
        private String timeStamp;
        private String nonceStr;
        private String signature;

        public String getAppid() {
            return appid;
        }

        public void setAppid(String appid) {
            this.appid = appid;
        }

        public String getTimeStamp() {
            return timeStamp;
        }

        public void setTimeStamp(String timeStamp) {
            this.timeStamp = timeStamp;
        }

        public String getNonceStr() {
            return nonceStr;
        }

        public void setNonceStr(String nonceStr) {
            this.nonceStr = nonceStr;
        }

        public String getSignature() {
            return signature;
        }

        public void setSignature(String signature) {
            this.signature = signature;
        }
    }

    public JsApiRegistResJson getJsApiRegist(String url){
        String jsTicket = getJsTicket();
        if (jsTicket == null){
            return null;
        }
        String timeStamp = (""+System.currentTimeMillis()).substring(0,10);
        String nonceStr = System.currentTimeMillis()+"Test";

        String signature = SHA1.encode(
                "jsapi_ticket="+jsTicket+
                        "&noncestr="+nonceStr +
                        "&timestamp="+timeStamp +
                        "&url="+url
        );
        JsApiRegistResJson json = new JsApiRegistResJson();
        json.appid = appid;
        json.timeStamp = timeStamp;
        json.nonceStr = nonceStr;
        json.signature = signature;
        return json;
    }

    // 获取 jsTicket（避免过时）
    private String getJsTicket(){
        if (jsTicket == null){
            jsTicket = refreshJsTicket();
            lastGetTime = System.currentTimeMillis();
        }else {
            if ((System.currentTimeMillis() - lastGetTime) > 1000 * 7200){
                jsTicket = refreshJsTicket();
                lastGetTime = System.currentTimeMillis();
            }
        }
        return jsTicket;
    }

    // 刷新 JsTicket
    private String refreshJsTicket(){
        if (accessToken == null){
            accessToken = getAccessToken();
        }
        Request request = new Request.Builder()
                .get()
                .url("https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token="+accessToken+"&type=jsapi")
                .build();
        try {
            Response response = httpClient.newCall(request).execute();
            if (response.isSuccessful()) {
                JSONObject json = JSONObject.parseObject(response.body().string());
                String ticketTemp = json.getString("ticket");
                if (ticketTemp != null){
                    System.out.println("刷新 jsTicket 成功" + ticketTemp);
                    return ticketTemp;
                }else {
                    return null;
                }
            }else {
                return null;
            }
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }

    // 获取 AccessToken
    private String getAccessToken(){
        Request request = new Request.Builder()
                .get()
                .url("https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid="+appid+"&secret="+secret)
                .build();
        try {
            Response response = httpClient.newCall(request).execute();
            if (response.isSuccessful()){
                JSONObject json = JSONObject.parseObject(response.body().string());
                String accessToken;
                if ((accessToken = json.getString("access_token") )!= null){
                    System.out.println("获取 accessToken 成功" + accessToken);
                    return accessToken;
                }else {
                    return null;
                }
            }else {
                return null;
            }
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }


    }

}