/* 寫cookie */function setCookie(name, value) {  var Days = 30;  var exp = new Date();  exp.setTime(exp.getTime() + Days * 24 * 60 * 60 * 1000);  document.cookie = name + "=" + escape(value) + ";expires=" + exp.toGMTString() + ";path=/";}/* 讀cookie */function getCookie(name) {  var arr = document.cookie.match(new RegExp("(^| )" + name + "=([^;]*)(;|$)"));  if (arr != null) {    return unescape(arr[2]);  }  return null;}/* 獲取URL參數(shù) */function getUrlParams(name) {  var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)", "i");  var r = window.location.search.substr(1).match(reg);  if (r != null) {    return unescape(r[2]);  }  return null;}/* 獲取openid */function getOpenId(url) {  var openid = getCookie("usropenid");  if (openid == null) {    openid = getUrlParams('openid');    alert("openid="+openid);    if (openid == null) {      window.location.href = "wxcode?url=" + url;    } else {      setCookie("usropenid", openid);    }  }}

//訪問微信獲取code@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)    throws ServletException, IOException {  String state = req.getParameter("url");  //WxOpenIdServlet的地址  String redirect ="http://"+Configure.SITE+"/wxopenid";  redirect = URLEncoder.encode(redirect, "utf-8");  StringBuffer url = new StringBuffer("https://open.weixin.qq.com/connect/oauth2/authorize?appid=")      .append(Configure.APP_ID).append("&redirect_uri=").append(redirect)      .append("&response_type=code&scope=snsapi_base&state=").append(state).append("#wechat_redirect");  resp.sendRedirect(url.toString());}

//訪問微信獲取openid@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)    throws ServletException, IOException {  String code = req.getParameter("code");  String state = req.getParameter("state");  Result ret = new Result();  AuthToken token = WXUtil.getAuthToken(code);  if(null != token.getOpenid()){    ret.setCode(0);    log.info("====openid=="+token.getOpenid());    Map<String,String> map = new HashMap<String,String>();    map.put("openid", token.getOpenid());    map.put("state", state);    ret.setData(map);  }else{    ret.setCode(-1);    ret.setMsg("登錄錯誤");  }  String redUrl = state+"?openid="+token.getOpenid();  resp.sendRedirect(redUrl);}

public static AuthToken getAuthToken(String code){  AuthToken vo = null;  try {    String uri = "https://api.weixin.qq.com/sns/oauth2/access_token?";    StringBuffer url = new StringBuffer(uri);    url.append("appid=").append(Configure.APP_ID);    url.append("&secret=").append(Configure.APP_SECRET);    url.append("&code=").append(code);    url.append("&grant_type=").append("authorization_code");    HttpURLConnection conn = HttpClientUtil.CreatePostHttpConnection(url.toString());    InputStream input = null;    if (conn.getResponseCode() == 200) {      input = conn.getInputStream();    } else {      input = conn.getErrorStream();    }    vo = JSON.parseObject(new String(HttpClientUtil.readInputStream(input),"utf-8"),AuthToken.class);  } catch (Exception e) {    log.error("getAuthToken error", e);  }  return vo;}

package com.huatek.shebao.util;import java.io.ByteArrayOutputStream;import java.io.DataOutputStream;import java.io.IOException;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.ProtocolException;import java.net.URL;public class HttpClientUtil {  // 設置body體  public static void setBodyParameter(String sb, HttpURLConnection conn)      throws IOException {    DataOutputStream out = new DataOutputStream(conn.getOutputStream());    out.writeBytes(sb);    out.flush();    out.close();  }  // 添加簽名header  public static HttpURLConnection CreatePostHttpConnection(String uri) throws MalformedURLException,      IOException, ProtocolException {    URL url = new URL(uri);    HttpURLConnection conn = (HttpURLConnection) url.openConnection();    conn.setUseCaches(false);    conn.setDoInput(true);    conn.setDoOutput(true);    conn.setRequestMethod("POST");    conn.setInstanceFollowRedirects(true);    conn.setConnectTimeout(30000);    conn.setReadTimeout(30000);    conn.setRequestProperty("Content-Type","application/json");    conn.setRequestProperty("Accept-Charset", "utf-8");    conn.setRequestProperty("contentType", "utf-8");    return conn;  }  public static byte[] readInputStream(InputStream inStream) throws Exception {    ByteArrayOutputStream outStream = new ByteArrayOutputStream();    byte[] buffer = new byte[1024];    int len = 0;    while ((len = inStream.read(buffer)) != -1) {      outStream.write(buffer, 0, len);    }    byte[] data = outStream.toByteArray();    outStream.close();    inStream.close();    return data;  }}

package com.huatek.shebao.wxpay;public class AuthToken {  private String access_token;  private Long expires_in;  private String refresh_token;  private String openid;  private String scope;  private String unionid;  private Long errcode;  private String errmsg;  public String getAccess_token() {    return access_token;  }  public void setAccess_token(String access_token) {    this.access_token = access_token;  }  public Long getExpires_in() {    return expires_in;  }  public void setExpires_in(Long expires_in) {    this.expires_in = expires_in;  }  public String getRefresh_token() {    return refresh_token;  }  public void setRefresh_token(String refresh_token) {    this.refresh_token = refresh_token;  }  public String getOpenid() {    return openid;  }  public void setOpenid(String openid) {    this.openid = openid;  }  public String getScope() {    return scope;  }  public void setScope(String scope) {    this.scope = scope;  }  public String getUnionid() {    return unionid;  }  public void setUnionid(String unionid) {    this.unionid = unionid;  }  public Long getErrcode() {    return errcode;  }  public void setErrcode(Long errcode) {    this.errcode = errcode;  }  public String getErrmsg() {    return errmsg;  }  public void setErrmsg(String errmsg) {    this.errmsg = errmsg;  }}