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); 
}