Question

我不是一名专业的java脚本程序员。我希望你能帮助我。

我编写了一个使用ajax列出端口状态的代码。例如site：google.com端口：从24到80。但是当我尝试使用Javascript For循环列出输出时它不起作用。代码是[index.php]：

<div id="inputform"><span>Enter URL or IP</span>
  <input type="text" name="urladress" id="urladress" size=25 maxlength=100 value="<?php if (isset($_POST['urladress'])){echo $_POST['urladress'];}; ?>"></br>
  from port
  <input type="text" name="fromport" id="fromport" size=5 maxlength=6 value="<?php if (isset($_POST['fromport'])){echo $_POST['fromport'];}else{echo "1";} ; ?>">
  to:
  <input type="text" name="toport" id="toport" size=5 maxlength=6 value="<?php if (isset($_POST['toport'])){echo $_POST['toport'];}else{echo "24";} ;; ?>">
  <input type="button" value="submit" onClick="getresults();" class="btn">
</div>
<div id="result" name="result"> </div>
<script language="javascript" type="text/javascript">
    // Get the HTTP Object
    function getHTTPObject(){
        if (window.ActiveXObject) return new ActiveXObject("Microsoft.XMLHTTP");
            else if (window.XMLHttpRequest) return new XMLHttpRequest();
        else {
            alert("Ajax not supported.");
            return null;
        }
    }
    // Change the value of the outputText field
    function setOutput(){

        document.getElementById('result').innerHTML += httpObject.responseText;

    }
    // Implement business logic
    function getresults(){
        document.getElementById('result').innerHTML = "calculating</br>"
        httpObject = getHTTPObject();
        if (httpObject != null) 
        {
            var fromport = document.getElementById('fromport').value;
            var toport = document.getElementById('toport').value;
            if (fromport>toport || toport=='' || fromport==''){alert('wrong values');return 0;}

            for(var i=fromport;i<=toport;i++){
                httpObject.open("GET", "portscanner.php?inputText="+document.getElementById('urladress').value+"&port="+i, true);
                httpObject.send(null);
                httpObject.onreadystatechange = setOutput;
            }

        }
    }
    var httpObject = null;
    </script>
</div>

服务器端[portscan.php]：

<?php
if (isset($_GET['inputText'])){
    $url=$_GET['inputText'];
    $url = str_replace("http://","",$url);
    $url = str_replace("www.","",$url);
    $port=$_GET['port'];
    $fp = @fsockopen($url,$port,$errno,$errstr,2);
    if(!$fp)
    {
        echo "port #". $port . "is closed</br>";
    }
    else
    {
        echo "Port #".$port."is open.</br>";
        fclose($fp);
    }
};
?>

它只显示上一个端口的结果：例如site：http：//stackoverflow.com ports：从70到80显示：

calculating
Port #80is open.
Port #80is open.

应该看起来像：

calculating
Port #70is closed.
Port #71is closed.
Port #72is closed.
...
Port #79is closed.
Port #80is open.

Answer 1

每次循环执行时都会覆盖httpObject。您可能需要一个httpObjects数组来处理这个问题。

OnReadyStateChange不是阻塞命令，所以FOR循环将一直持续到最后一次。

更改这样的功能：

// Change the value of the outputText field
function setOutput(index){
    if(this.readyState == 4) // Done
    {
        if(this.status == 200)
            document.getElementById('result').innerHTML += this.responseText;
        else
            document.getElementById('result').innerHTML += "Error occured : " + this.status + "<br>";
    }
}
// Implement business logic
function getresults(){
    document.getElementById('result').innerHTML = "calculating</br>";
    var fromport = document.getElementById('fromport').value;
    var toport = document.getElementById('toport').value;
    if (fromport>toport || toport=='' || fromport==''){alert('wrong values');return 0;}

    for(var i=fromport;i<=toport;i++){
        var index = httpObject.push(getHTTPObject()) - 1;
        httpObject[index].open("GET", "test.php?inputText="+document.getElementById('urladress').value+"&port="+i, true);
        httpObject[index].send(null);
        httpObject[index].onreadystatechange = setOutput;
    }
}
var httpObject = new Array();

Answer 2

我写过一篇很长的答案，关于你如何只更新httpObject.responseText的值，因为你决定是否在httpObject存在的情况下调用服务器。

然后就在我即将点击“发布”时，我在函数末尾找到了var httpObject = null;行。我也不知道JavaScript是否足以判断这是否是错误，但是尝试删除var（我认为使变量本地化为封闭块 - 就像我说的那样，我是JavaScript的新手。）

更好的是，重写这些例程以避免httpObject全局变量。也许传递一个带有httpObject.responseText结果的字符串，而不是依赖于该对象存在于另一个函数中。

Answer 3

我没有尝试过你的代码，但我认为你应该在循环中创建XmlHttpObject。用于多个异步请求的相同对象可能是个问题。

使用Ajax列出site / ip Ports状态

3 个答案: