AlipayClient alipayClient = new DefaultAlipayClient("https://openapi.alipay.com/gateway.do","app_id","your private_key","json","GBK","alipay_public_key","RSA2");
AlipayPlatformUseridGetRequest request = new AlipayPlatformUseridGetRequest();
request.setBizContent("{" +
"      \"open_ids\":[" +
"        \"20881017798171549451807262713691\",\"20881017798171549451807262713691\"" +
"      ]" +
"  }");
AlipayPlatformUseridGetResponse response = alipayClient.execute(request);
if(response.isSuccess()){
System.out.println("调用成功");
} else {
System.out.println("调用失败");
}

IAopClient client = new DefaultAopClient("https://openapi.alipay.com/gateway.do", "app_id", "merchant_private_key", "json", "1.0", "RSA2", "alipay_public_key", "GBK", false);
AlipayPlatformUseridGetRequest  request= new AlipayPlatformUseridGetRequest() ;
request.BizContent="{" +
"      \"open_ids\":[" +
"        \"20881017798171549451807262713691\",\"20881017798171549451807262713691\"" +
"      ]" +
"  }";
AlipayPlatformUseridGetResponse response=client.Execute(request);
Console.WriteLine(response.Body);

$aop = new AopClient ();
$aop->gatewayUrl = 'https://openapi.alipay.com/gateway.do';
$aop->appId = 'your app_id';
$aop->rsaPrivateKey = '请填写开发者私钥去头去尾去回车，一行字符串';
$aop->alipayrsaPublicKey='请填写支付宝公钥，一行字符串';
$aop->apiVersion = '1.0';
$aop->signType = 'RSA2';
$aop->postCharset='GBK';
$aop->format='json';
$request = new AlipayPlatformUseridGetRequest ();
$request->setBizContent("{" .
"      \"open_ids\":[" .
"        \"20881017798171549451807262713691\",\"20881017798171549451807262713691\"" .
"      ]" .
"  }");
$result = $aop->execute ( $request); 

$responseNode = str_replace(".", "_", $request->getApiMethodName()) . "_response";
$resultCode = $result->$responseNode->code;
if(!empty($resultCode)&&$resultCode == 10000){
echo "成功";
} else {
echo "失败";
}

https://openapi.alipay.com/gateway.do?timestamp=2013-01-01 08:08:08&method=alipay.platform.userid.get&app_id=1130&sign_type=RSA2&sign=ERITJKEIJKJHKKKKKKKHJEREEEEEEEEEEE&version=1.0&biz_content=
  {
      "open_ids":[
        "20881017798171549451807262713691","20881017798171549451807262713691"
      ]
  }

//为确保安全通信，需自行验证响应示例中的sign值是否为蚂蚁金服所提供。

{
	"alipay_platform_userid_get_response":{
		"msg":"Success",
		"code":"10000",
		"dict":"{\"20881024598281958648689631813682\":\"2088102011745823\",\"20881017798171549451807262713691\":\"2088102118109919\"}"
	},
	"sign":"ERITJKEIJKJHKKKKKKKHJEREEEEEEEEEEE"
}

{
	"alipay_platform_userid_get_response":{
		"msg":"Service Currently Unavailable",
		"code":"20000",
		"sub_msg":"系统繁忙",
		"sub_code":"isp.unknow-error"
	},
	"sign":"ERITJKEIJKJHKKKKKKKHJEREEEEEEEEEEE"
}