微信JSSDK调用微信扫一扫功能的方法

<script type="text/javascript" http://test.com/zepto_touch.js"></script> 
<script type="text/javascript" src="http://res.wx.qq.com/open/js/jweixin-1.0.0.js"></script> 

<img src="../../../images/right.jpg" onclick="scanCode()" class="img"> 

<script type="text/javascript"> 
 var _appId = "wxz88dbd30e5580e59"; 
 var _data = { 
  appId : _appId, 
  url : location.href, 
  t : Math.random() 
 }; 
 var _getWechatSignUrl = 'http://test.com/getWechatSign.do'; 
 
 // 获取微信签名 
 $.ajax({ 
  url : _getWechatSignUrl, 
  data : _data, 
  success : function(o) { 
   console.log(o); 
   if (o.returnCode == "00") { 
    wxConfig(o.detail[0].timestamp, o.detail[0].nonceStr, o.detail[0].signature); 
   } 
  } 
 }); 
 function wxConfig(_timestamp, _nonceStr, _signature) { 
  //alert('获取数据：'+_timestamp+'\n'+_nonceStr+'\n'+_signature); 
  console.log('获取数据：' + _timestamp + '\n' + _nonceStr + '\n' + _signature); 
  wx.config({ 
   debug : true, // 开启调试模式,调用的所有api的返回值会在客户端alert出来，若要查看传入的参数，可以在pc端打开，参数信息会通过log打出，仅在pc端时才会打印。 
   appId : _appId, // 必填，公众号的唯一标识 
   timestamp : _timestamp, // 必填，生成签名的时间戳 
   nonceStr : _nonceStr, // 必填，生成签名的随机串 
   signature : _signature,// 必填，签名，见附录1 
   jsApiList : [ 'onMenuShareTimeline', 'onMenuShareAppMessage', 
     'onMenuShareQQ', 'onMenuShareWeibo', 'scanQRCode' ] 
  // 必填，需要使用的JS接口列表，所有JS接口列表见附录2 
  }); 
 } 
 function scanCode() { 
  wx.scanQRCode({ 
   needResult : 1, 
   scanType : [ "qrCode", "barCode" ], 
   success : function(res) { 
    console.log(res) 
    alert(JSON.stringify(res)); 
    var result = res.resultStr; 
   }, 
   fail : function(res) { 
    console.log(res) 
    alert(JSON.stringify(res)); 
 
   } 
  }); 
 } 
</script> 

Long timestamp = System.currentTimeMillis() / 1000; 

String nonceStr = RandomStringUtils.randomAlphanumeric(16); 

public static String getSign(String jsapi_ticket, String noncestr, Long timestamp, String url) 
  throws NoSuchAlgorithmException { 
 String shaStr = "jsapi_ticket=" + jsapi_ticket + "&noncestr=" + noncestr + "×tamp=" + timestamp + "&url=" 
   + url; 
 MessageDigest mDigest = MessageDigest.getInstance("SHA1"); 
 byte[] result = mDigest.digest(shaStr.getBytes()); 
 StringBuffer signature = new StringBuffer(); 
 for (int i = 0; i < result.length; i++) { 
  signature.append(Integer.toString((result[i] & 0xff) + 0x100, 16).substring(1)); 
 } 
 return signature.toString(); 
}