java 获取微信 页面授权 获取用户openid

先调用微信的地址 跳转https://open.weixin.qq.com/connect/oauth2/authorize?appid=wx4b4009c4fce00e0c&redirect_uri=这里填写你要跳到请求页面授权域名l&response_type=code&scope=snsapi_base&state=123#wechat_redirect

返回redirect_uri/?code=""&status="";

拿到code就可获取openid以及用户信息

先上 工具类

 package com.yulv.utils;

 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.net.HttpURLConnection;
 import java.net.InetSocketAddress;
 import java.net.Proxy;
 import java.net.URL;
 import java.net.URLConnection;
 import java.util.Iterator;
 import java.util.Map;

 public class HttpRequestor {
      private String charset = "utf-8";
         private Integer connectTimeout = null;
         private Integer socketTimeout = null;
         private String proxyHost = null;
         private Integer proxyPort = null;

         /**
          * Do GET request
          * @param url
          * @return
          * @throws Exception
          * @throws IOException
          */
         public String doGet(String url) throws Exception {

             URL localURL = new URL(url);

             URLConnection connection = openConnection(localURL);
             HttpURLConnection httpURLConnection = (HttpURLConnection)connection;

             httpURLConnection.setRequestProperty("Accept-Charset", charset);
             httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

             InputStream inputStream = null;
             InputStreamReader inputStreamReader = null;
             BufferedReader reader = null;
             StringBuffer resultBuffer = new StringBuffer();
             String tempLine = null;

             if (httpURLConnection.getResponseCode() >= 300) {
                 throw new Exception("HTTP Request is not success, Response code is " + httpURLConnection.getResponseCode());
             }

             try {
                 inputStream = httpURLConnection.getInputStream();
                 inputStreamReader = new InputStreamReader(inputStream,"UTF-8");
                 reader = new BufferedReader(inputStreamReader);

                 while ((tempLine = reader.readLine()) != null) {
                     resultBuffer.append(tempLine);
                 }

             } finally {

                 if (reader != null) {
                     reader.close();
                 }

                 if (inputStreamReader != null) {
                     inputStreamReader.close();
                 }

                 if (inputStream != null) {
                     inputStream.close();
                 }

             }

             return resultBuffer.toString();
         }

         /**
          * Do POST request
          * @param url
          * @param parameterMap
          * @return
          * @throws Exception
          */
         public String doPost(String url, Map parameterMap) throws Exception {

             /* Translate parameter map to parameter date string */
             StringBuffer parameterBuffer = new StringBuffer();
             if (parameterMap != null) {
                 Iterator iterator = parameterMap.keySet().iterator();
                 String key = null;
                 String value = null;
                 while (iterator.hasNext()) {
                     key = (String)iterator.next();
                     if (parameterMap.get(key) != null) {
                         value = (String)parameterMap.get(key);
                     } else {
                         value = "";
                     }

                     parameterBuffer.append(key).append("=").append(value);
                     if (iterator.hasNext()) {
                         parameterBuffer.append("&");
                     }
                 }
             }

             System.out.println("POST parameter : " + parameterBuffer.toString());

             URL localURL = new URL(url);

             URLConnection connection = openConnection(localURL);
             HttpURLConnection httpURLConnection = (HttpURLConnection)connection;

             httpURLConnection.setDoOutput(true);
             httpURLConnection.setRequestMethod("POST");
             httpURLConnection.setRequestProperty("Accept-Charset", charset);
             httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
             httpURLConnection.setRequestProperty("Content-Length", String.valueOf(parameterBuffer.length()));

             OutputStream outputStream = null;
             OutputStreamWriter outputStreamWriter = null;
             InputStream inputStream = null;
             InputStreamReader inputStreamReader = null;
             BufferedReader reader = null;
             StringBuffer resultBuffer = new StringBuffer();
             String tempLine = null;

             try {
                 outputStream = httpURLConnection.getOutputStream();
                 outputStreamWriter = new OutputStreamWriter(outputStream);

                 outputStreamWriter.write(parameterBuffer.toString());
                 outputStreamWriter.flush();

                 if (httpURLConnection.getResponseCode() >= 300) {
                     throw new Exception("HTTP Request is not success, Response code is " + httpURLConnection.getResponseCode());
                 }

                 inputStream = httpURLConnection.getInputStream();
                 inputStreamReader = new InputStreamReader(inputStream);
                 reader = new BufferedReader(inputStreamReader);

                 while ((tempLine = reader.readLine()) != null) {
                     resultBuffer.append(tempLine);
                 }

             } finally {

                 if (outputStreamWriter != null) {
                     outputStreamWriter.close();
                 }

                 if (outputStream != null) {
                     outputStream.close();
                 }

                 if (reader != null) {
                     reader.close();
                 }

                 if (inputStreamReader != null) {
                     inputStreamReader.close();
                 }

                 if (inputStream != null) {
                     inputStream.close();
                 }

             }

             return resultBuffer.toString();
         }

         private URLConnection openConnection(URL localURL) throws IOException {
             URLConnection connection;
             if (proxyHost != null && proxyPort != null) {
                 Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress(proxyHost, proxyPort));
                 connection = localURL.openConnection(proxy);
             } else {
                 connection = localURL.openConnection();
             }
             return connection;
         }

         /**
          * Render request according setting
          * @param request
          */
         private void renderRequest(URLConnection connection) {

             if (connectTimeout != null) {
                 connection.setConnectTimeout(connectTimeout);
             }

             if (socketTimeout != null) {
                 connection.setReadTimeout(socketTimeout);
             }

         }

         /*
          * Getter & Setter
          */
         public Integer getConnectTimeout() {
             return connectTimeout;
         }

         public void setConnectTimeout(Integer connectTimeout) {
             this.connectTimeout = connectTimeout;
         }

         public Integer getSocketTimeout() {
             return socketTimeout;
         }

         public void setSocketTimeout(Integer socketTimeout) {
             this.socketTimeout = socketTimeout;
         }

         public String getProxyHost() {
             return proxyHost;
         }

         public void setProxyHost(String proxyHost) {
             this.proxyHost = proxyHost;
         }

         public Integer getProxyPort() {
             return proxyPort;
         }

         public void setProxyPort(Integer proxyPort) {
             this.proxyPort = proxyPort;
         }

         public String getCharset() {
             return charset;
         }

         public void setCharset(String charset) {
             this.charset = charset;
         }
 }

直接获取

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        String code = request.getParameter("code");
        String appid = "wx4b4009c4fce00e0c";
        String secret = "4d3aea976157935e563f8ef01c7a4293";
        String requestUrl = "https://api.weixin.qq.com/sns/oauth2/access_token?appid="+appid+"&secret="+secret+"&code="+wxCode+"&grant_type=authorization_code";
        //第一次请求 获取access_token 和 openid
        String  oppid = new HttpRequestor().doGet(requestUrl);
        JSONObject oppidObj =JSONObject.fromObject(oppid);
        String access_token = (String) oppidObj.get("access_token");
        String openid = (String) oppidObj.get("openid");
        String requestUrl2 = "https://api.weixin.qq.com/sns/userinfo?access_token="+access_token+"&openid="+openid+"&lang=zh_CN";
        String userInfoStr = new HttpRequestor().doGet(requestUrl2);
        JSONObject wxUserInfo =JSONObject.fromObject(userInfoStr);
}