java后台调用短信接口，实现发送短信验证码的控制层实现

1.设计:用户填写手机号，点击获取验证码按钮，controller层获得所要发送验证码的手机号，随机生成六位数的验证码。调用发送短信接口url向此手机号发送验证码。注意：下面的代码采用的是云信使的短信验证码接口，不同的验证码更换不同的url格式，即可。
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@RequestMapping(value = "/sendValidate")
public void sendValidate(HttpServletRequest request,HttpServletResponse response) throws MalformedURLException {
    String vcode = "";
    String phonenumber = request.getParameter("phonenumber");
    URL url;
    String str = null;
    JSONObject json = new JSONObject();
    //生成验证码 
    for (int i = 0; i < 6; i++) {
        vcode = vcode + (int) (Math.random() * 9);
    }

    User us = userService.getUserMessage(phonenumber);
    if (us != null) {
        json.put("status", -2);// 电话号码已被注册过
        try {
            ResponseUtil.write(response, json.toString());
        } catch (Exception e1) {
        }
        return;
    }
    try {
         url = new URL(
         "http://api.sms.cn/sms/?ac=send&uid=用户名&pwd=你注册时md5加密的密码&template=100006&mobile="+phonenumber+"&content={code:"+vcode+"}");
         URLConnection connection = url.openConnection();
        connection.setDoOutput(true);      
        DataInputStream read= new
    DataInputStream(connection.getInputStream());
        str = read.readUTF();
    } catch (Exception e) {
        json.put("status", -1);// 服务器端错误,例如没网了
        try {
            ResponseUtil.write(response, json.toString());
        } catch (Exception e1) {
        }
        return;
    }
    if (str != null && str.substring(6, 9).equals("100") == true) {
        json.put("status", 1);// 验证码发送成功
    } else
        json.put("status", 0);// 验证码发送失败
    try {
        ResponseUtil.write(response, json.toString());
    } catch (Exception e) {
        e.printStackTrace();
    }

}`