openid可以标识一个用户,session_key会变,所以来获取一下openid。
openid不能在微信小程序中直接获取,需要后台发送请求到微信的接口,然后微信返回一个json格式的字符串到后台,后台处理之后,再返回到微信小程序。
发布的小程序需要https的域名,而测试的时候可以使用http。
小程序在app.js中,修改login()中的内容:
// 登录 wx.login({ success: res => { // 发送 res.code 到后台换取 openId, sessionKey, unionId if (res.code) { wx.request({ url: ‘http://localhost:84/user/login‘, method: ‘POST‘, data: { code: res.code }, header: { ‘content-type‘: ‘application/x-www-form-urlencoded‘ }, success(res) { console.log("openid:"+res.data.openid); if (res.data.openid != "" || res.data.openid!=null){ // 登录成功 wx.setStorageSync("openid", res.data.openid);//将用户id保存到缓存中 wx.setStorageSync("session_key", res.data.session_key);//将session_key保存到缓存中 }else{ // 登录失败 // TODO 跳转到错误页面,要求用户重试 return false; } } }) } else { console.log(‘获取用户登录态失败!‘ + res.errMsg) } } })
这里请求的http://localhost:84/user/login
后台的处理类:
package com.ft.feathertrade.handler; import com.fasterxml.jackson.databind.ObjectMapper; import com.ft.feathertrade.entity.OpenIdJson; import com.ft.feathertrade.utils.HttpUtil; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; import java.io.IOException; @RestController public class LoginHandler { private String appID = ""; private String appSecret = ""; @PostMapping("/user/login") public String userLogin(@RequestParam("code") String code) throws IOException { String result = ""; try{//请求微信服务器,用code换取openid。HttpUtil是工具类,后面会给出实现,Configure类是小程序配置信息,后面会给出代码 result = HttpUtil.doGet( "https://api.weixin.qq.com/sns/jscode2session?appid=" + this.appID + "&secret=" + this.appSecret + "&js_code=" + code + "&grant_type=authorization_code", null); } catch (Exception e) { e.printStackTrace(); } ObjectMapper mapper = new ObjectMapper(); OpenIdJson openIdJson = mapper.readValue(result,OpenIdJson.class); System.out.println(result.toString()); System.out.println(openIdJson.getOpenid()); return result; } }
HttpUtil工具类:
package com.ft.feathertrade.utils; import java.io.BufferedReader; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.URL; import java.net.URLEncoder; import java.util.HashMap; import java.util.Map.Entry; import java.util.Set; import org.apache.commons.httpclient.HttpStatus;//此类需要添加maven依赖或jar包 /** 将此依赖添加到pom.xml中 <dependency> <groupId>commons-httpclient</groupId> <artifactId>commons-httpclient</artifactId> <version>3.1</version> </dependency> **/ public class HttpUtil { public static String doGet(String urlPath, HashMap<String, Object> params) throws Exception { StringBuilder sb = new StringBuilder(urlPath); if (params != null && !params.isEmpty()) { // 说明有参数 sb.append("?"); Set<Entry<String, Object>> set = params.entrySet(); for (Entry<String, Object> entry : set) { // 遍历map里面的参数 String key = entry.getKey(); String value = ""; if (null != entry.getValue()) { value = entry.getValue().toString(); // 转码 value = URLEncoder.encode(value, "UTF-8"); } sb.append(key).append("=").append(value).append("&"); } sb.deleteCharAt(sb.length() - 1); // 删除最后一个& } // System.out.println(sb.toString()); URL url = new URL(sb.toString()); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setConnectTimeout(5000); // 5s超时 conn.setRequestMethod("GET"); if (conn.getResponseCode() == HttpStatus.SC_OK) {// HttpStatus.SC_OK == // 200 BufferedReader reader = new BufferedReader(new InputStreamReader( conn.getInputStream())); StringBuilder sbs = new StringBuilder(); String line; while ((line = reader.readLine()) != null) { sbs.append(line); } return sbs.toString(); } return null; } }
OpenIdJson的实体类:
package com.ft.feathertrade.entity; public class OpenIdJson { private String openid; private String session_key; public String getOpenid() { return openid; } public void setOpenid(String openid) { this.openid = openid; } public String getSession_key() { return session_key; } public void setSession_key(String session_key) { this.session_key = session_key; } }
参考自:https://blog.csdn.net/qq_20372833/article/details/89597420