微信扫码登录实现

1.前端准备

定义一个div容器，用于展示生成的二维码

<div id="weixinLogin"></div>

安装二维码插件

npm install vue-qriously --save-dev

在main.js中进行引入插件

import VueQriously from 'vue-qriously'

Vue.use(VueQriously)

编写一个微信二维码生成插件的方法

    weixinLogin() {
      getLoginParam().then( response=>{
            var obj = new WxLogin({
              self_redirect:true,
              id: 'weixinLogin', // 需要显示的容器id
              appid: response.data.appid, // 公众号appid wx*******
              scope: response.data.scope, // 网页默认即可
              redirect_uri: response.data.redirectUrl, //redirectUrl// 授权成功后回调的url
              state: response.data.state, // 可设置为简单的随机数加session用来校验
              style: 'black', // 提供"black"、"white"可选。二维码的样式
              href: '' // 外部css文件url，需要https
            })
      })
    },

注意：此处需要的参数定义在后端，需要调用接口来获取，对应接口如下

api：

const BASEURL = "/api/user/wx";
//获取微信参数
export function getLoginParam() {
  return request({
    url: `${BASEURL}/getLoginParam/`,
    method: "get",
  });
}

2.后端实现

后端接口实现：

WX_OPEN_REDIRECT_URL为 http://localhost:8160/api/user/wx/callback

这里的url即为扫描成功后跳转的页面

    /**
     * 获取二维码相关参数
     */
    @GetMapping("getLoginParam")
    @ResponseBody
    public Result getLoginParam() {
        Map<String, Object> map = new HashMap<>();
        map.put("appid", ConstantWxUtils.WX_OPEN_APP_ID);
        map.put("scope", "snsapi_login");
        //对redirect_url进行URLEncoder编码
        String redirectUrl = ConstantWxUtils.WX_OPEN_REDIRECT_URL;
        try {
            redirectUrl = URLEncoder.encode(redirectUrl, "utf-8");
        } catch (Exception e) {
            e.printStackTrace();
        }
        map.put("redirectUrl", redirectUrl);
        map.put("response_type", "code");
        map.put("state", "Eric");
        return Result.ok(map);
    }

远程调用微信接口可能用到的工具类

package com.gh.util;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.http.Consts;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.config.RequestConfig.Builder;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.ConnectTimeoutException;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLContextBuilder;
import org.apache.http.conn.ssl.TrustStrategy;
import org.apache.http.conn.ssl.X509HostnameVerifier;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;

import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLException;
import javax.net.ssl.SSLSession;
import javax.net.ssl.SSLSocket;
import java.io.IOException;
import java.net.SocketTimeoutException;
import java.security.GeneralSecurityException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

public class HttpClientUtils {

    public static final int connTimeout=10000;
    public static final int readTimeout=10000;
    public static final String charset="UTF-8";
    private static HttpClient client = null;

    static {
        PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
        cm.setMaxTotal(128);
        cm.setDefaultMaxPerRoute(128);
        client = HttpClients.custom().setConnectionManager(cm).build();
    }

    public static String postParameters(String url, String parameterStr) throws ConnectTimeoutException, SocketTimeoutException, Exception{
        return post(url,parameterStr,"application/x-www-form-urlencoded",charset,connTimeout,readTimeout);
    }

    public static String postParameters(String url, String parameterStr,String charset, Integer connTimeout, Integer readTimeout) throws ConnectTimeoutException, SocketTimeoutException, Exception{
        return post(url,parameterStr,"application/x-www-form-urlencoded",charset,connTimeout,readTimeout);
    }

    public static String postParameters(String url, Map<String, String> params) throws ConnectTimeoutException,
            SocketTimeoutException, Exception {
        return postForm(url, params, null, connTimeout, readTimeout);
    }

    public static String postParameters(String url, Map<String, String> params, Integer connTimeout,Integer readTimeout) throws ConnectTimeoutException,
            SocketTimeoutException, Exception {
        return postForm(url, params, null, connTimeout, readTimeout);
    }

    public static String get(String url) throws Exception {
        return get(url, charset, null, null);
    }

    public static String get(String url, String charset) throws Exception {
        return get(url, charset, connTimeout, readTimeout);
    }

    /**
     * 发送一个 Post 请求, 使用指定的字符集编码.
     *
     * @param url
     * @param body RequestBody
     * @param mimeType 例如 application/xml "application/x-www-form-urlencoded" a=1&b=2&c=3
     * @param charset 编码
     * @param connTimeout 建立链接超时时间,毫秒.
     * @param readTimeout 响应超时时间,毫秒.
     * @return ResponseBody, 使用指定的字符集编码.
     * @throws ConnectTimeoutException 建立链接超时异常
     * @throws SocketTimeoutException  响应超时
     * @throws Exception
     */
    public static String post(String url, String body, String mimeType,String charset, Integer connTimeout, Integer readTimeout)
            throws ConnectTimeoutException, SocketTimeoutException, Exception {
        HttpClient client = null;
        HttpPost post = new HttpPost(url);
        String result = "";
        try {
            if (StringUtils.isNotBlank(body)) {
                HttpEntity entity = new StringEntity(body, ContentType.create(mimeType, charset));
                post.setEntity(entity);
            }
            // 设置参数
            RequestConfig.Builder customReqConf = RequestConfig.custom();
            if (connTimeout != null) {
                customReqConf.setConnectTimeout(connTimeout);
            }
            if (readTimeout != null) {
                customReqConf.setSocketTimeout(readTimeout);
            }
            post.setConfig(customReqConf.build());

            HttpResponse res;
            if (url.startsWith("https")) {
                // 执行 Https 请求.
                client = createSSLInsecureClient();
                res = client.execute(post);
            } else {
                // 执行 Http 请求.
                client = HttpClientUtils.client;
                res = client.execute(post);
            }
            result = IOUtils.toString(res.getEntity().getContent(), charset);
        } finally {
            post.releaseConnection();
            if (url.startsWith("https") && client != null&& client instanceof CloseableHttpClient) {
                ((CloseableHttpClient) client).close();
            }
        }
        return result;
    }


    /**
     * 提交form表单
     *
     * @param url
     * @param params
     * @param connTimeout
     * @param readTimeout
     * @return
     * @throws ConnectTimeoutException
     * @throws SocketTimeoutException
     * @throws Exception
     */
    public static String postForm(String url, Map<String, String> params, Map<String, String> headers, Integer connTimeout,Integer readTimeout) throws ConnectTimeoutException,
            SocketTimeoutException, Exception {

        HttpClient client = null;
        HttpPost post = new HttpPost(url);
        try {
            if (params != null && !params.isEmpty()) {
                List<NameValuePair> formParams = new ArrayList<NameValuePair>();
                Set<Entry<String, String>> entrySet = params.entrySet();
                for (Entry<String, String> entry : entrySet) {
                    formParams.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
                }
                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(formParams, Consts.UTF_8);
                post.setEntity(entity);
            }

            if (headers != null && !headers.isEmpty()) {
                for (Entry<String, String> entry : headers.entrySet()) {
                    post.addHeader(entry.getKey(), entry.getValue());
                }
            }
            // 设置参数
            Builder customReqConf = RequestConfig.custom();
            if (connTimeout != null) {
                customReqConf.setConnectTimeout(connTimeout);
            }
            if (readTimeout != null) {
                customReqConf.setSocketTimeout(readTimeout);
            }
            post.setConfig(customReqConf.build());
            HttpResponse res = null;
            if (url.startsWith("https")) {
                // 执行 Https 请求.
                client = createSSLInsecureClient();
                res = client.execute(post);
            } else {
                // 执行 Http 请求.
                client = HttpClientUtils.client;
                res = client.execute(post);
            }
            return IOUtils.toString(res.getEntity().getContent(), "UTF-8");
        } finally {
            post.releaseConnection();
            if (url.startsWith("https") && client != null
                    && client instanceof CloseableHttpClient) {
                ((CloseableHttpClient) client).close();
            }
        }
    }

    /**
     * 发送一个 GET 请求
     */
    public static String get(String url, String charset, Integer connTimeout,Integer readTimeout)
            throws ConnectTimeoutException,SocketTimeoutException, Exception {

        HttpClient client = null;
        HttpGet get = new HttpGet(url);
        String result = "";
        try {
            // 设置参数
            Builder customReqConf = RequestConfig.custom();
            if (connTimeout != null) {
                customReqConf.setConnectTimeout(connTimeout);
            }
            if (readTimeout != null) {
                customReqConf.setSocketTimeout(readTimeout);
            }
            get.setConfig(customReqConf.build());

            HttpResponse res = null;

            if (url.startsWith("https")) {
                // 执行 Https 请求.
                client = createSSLInsecureClient();
                res = client.execute(get);
            } else {
                // 执行 Http 请求.
                client = HttpClientUtils.client;
                res = client.execute(get);
            }

            result = IOUtils.toString(res.getEntity().getContent(), charset);
        } finally {
            get.releaseConnection();
            if (url.startsWith("https") && client != null && client instanceof CloseableHttpClient) {
                ((CloseableHttpClient) client).close();
            }
        }
        return result;
    }

    /**
     * 从 response 里获取 charset
     */
    @SuppressWarnings("unused")
    private static String getCharsetFromResponse(HttpResponse ressponse) {
        // Content-Type:text/html; charset=GBK
        if (ressponse.getEntity() != null  && ressponse.getEntity().getContentType() != null && ressponse.getEntity().getContentType().getValue() != null) {
            String contentType = ressponse.getEntity().getContentType().getValue();
            if (contentType.contains("charset=")) {
                return contentType.substring(contentType.indexOf("charset=") + 8);
            }
        }
        return null;
    }

    /**
     * 创建 SSL连接
     * @return
     * @throws GeneralSecurityException
     */
    private static CloseableHttpClient createSSLInsecureClient() throws GeneralSecurityException {
        try {
            SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy() {
                public boolean isTrusted(X509Certificate[] chain,String authType) throws CertificateException {
                    return true;
                }
            }).build();

            SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext, new X509HostnameVerifier() {

                @Override
                public boolean verify(String arg0, SSLSession arg1) {
                    return true;
                }

                @Override
                public void verify(String host, SSLSocket ssl)
                        throws IOException {
                }

                @Override
                public void verify(String host, X509Certificate cert)
                        throws SSLException {
                }

                @Override
                public void verify(String host, String[] cns,
                                   String[] subjectAlts) throws SSLException {
                }
            });
            return HttpClients.custom().setSSLSocketFactory(sslsf).build();

        } catch (GeneralSecurityException e) {
            throw e;
        }
    }
}

微信扫码登录回调

注意：扫码登录会自动获取一个随机code，这个code是微信发给用户的临时令牌。我们可以根据code再次请求微信第三方登陆接口得到access_token（正式令牌）

/**
     * 微信扫码登录回调
     */
    @GetMapping("callback")
    public String callback(String code, String state) {
        //拿着临时票据code和微信id和密钥，请求微信固定地址，得到两个值accessToken和openId
        //使用code和appid以及appscrect换取access_token
        StringBuffer baseAccessTokenUrl = new StringBuffer()
                .append("https://api.weixin.qq.com/sns/oauth2/access_token")
                .append("?appid=%s")
                .append("&secret=%s")
                .append("&code=%s")
                .append("&grant_type=authorization_code");

        String accessTokenUrl = String.format(baseAccessTokenUrl.toString(),
                ConstantWxUtils.WX_OPEN_APP_ID,
                ConstantWxUtils.WX_OPEN_APP_SECRET,
                code);//替换url中的值
        try {
            String accessTokenInfo = HttpClientUtils.get(accessTokenUrl);
            JSONObject jsonObject = JSONObject.parseObject(accessTokenInfo);
            String access_token = jsonObject.getString("access_token");
            String openid = jsonObject.getString("openid");
            //判断数据库是否存在扫描人信息
            UserInfo userInfo = userInfoService.findByOpenId(openid);
            if (userInfo == null) {
                //拿着access_token和openid去请求微信地址，得到扫描人信息
                String baseUserInfoUrl = "https://api.weixin.qq.com/sns/userinfo" +
                        "?access_token=%s" +
                        "&openid=%s";
                String userInfoUrl = String.format(baseUserInfoUrl, access_token, openid);
                String resultUserInfo = HttpClientUtils.get(userInfoUrl);
                JSONObject object = JSONObject.parseObject(resultUserInfo);
                //解析用户信息(头像，昵称等等)
                String headimgurl = object.getString("headimgurl");
                String nickname = object.getString("nickname");
                //添加数据库
                userInfo = new UserInfo();
                userInfo.setNickName(nickname);
                userInfo.setOpenid(openid);
                userInfo.setStatus(1);
                userInfoService.insert(userInfo);
            }
            //返回name和token字符串
            Map<String, Object> map = new HashMap<>();
            String name = userInfo.getName();
            if (StringUtils.isEmpty(name)) {
                name = userInfo.getNickName();
            }
            if (StringUtils.isEmpty(name)) {
                name = userInfo.getPhone();
            }
            map.put("name", name);
            //  前端判断openid不为空，需要绑定手机号，如果为空不要绑定手机号
            if (StringUtils.isEmpty(userInfo.getPhone())) {
                map.put("openid", openid);
            } else {
                map.put("openid", "");
            }
            String token = JwtHelper.createToken(userInfo.getId(), name);
            map.put("token", token);
            return "redirect:" + ConstantWxUtils.YYGH_BASE_URL + "/weixin/callback?token="+map.get("token")+"&openid="+map.get("openid")+"&name="+URLEncoder.encode((String)map.get("name"));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

注意：上述方法返回值是一个前端vue页面，这个页面作为一个中间页面callback.vue，用来获取返回携带的参数。

<template>
  <!-- header -->
  <div>
  </div>
  <!-- footer -->
</template>
<script>
export default {
//   layout: "empty",
  data() {
    return {
    }
  },
  mounted() {
    let token = this.$route.query.token
    let name = this.$route.query.name
    let openid = this.$route.query.openid
    // 调用父vue方法
    window.parent['loginCallback'](name, token, openid)
  }
}
</script>

在父组件进行接收：

mounted(){
    //微信回调的方法
    let self = this;
    window["loginCallback"] = (name,token, openid) => {
      self.loginCallback(name, token, openid);
    }
}

判断openid是否为空，如果不为空，需要绑定手机号，如果为空不要绑定手机号

    loginCallback(name, token, openid){
      console.log("openid="+openid)
      if(openid!=null){
        this.userInfo.openid=openid
        this.showLogin()
      }else{
        this.setCookies(name,token)
      }
    },

把name和token存在cookie

    setCookies(name, token) {
      cookie.set("token", token, { domain: "localhost" });
      cookie.set("name", name, { domain: "localhost" });
      window.location.reload();
    }