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javascript - 如何将值从 HTML 页面传递到 Java 小程序?

转载 作者:塔克拉玛干 更新时间:2023-11-02 22:26:27 26 4
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我试过像下面这样使用 javascript 传递值

<script language= "javascript" type= "text/javascript">
var num;
function getVal()
{
num=document.getElementById('in').value;
alert(document.getElementById('parm').value);
}
</script>
<body>
<form >
Number : <input type="text" id="in" ><br/>
<button id="myBtn" onclick="getVal()">Try it</button><br/>
</form>
<APPLET code="Calc.class" width="100" height="100">
<PARAM name="number" id="parm">
</APPLET>

</body>
</html>

警告框在屏幕上显示输入的值,但小程序代码显示的不同。我的小程序代码是

public class Calc extends Applet
{

private String strDefault = "Hello! Java Applet.";
public void paint(Graphics g) {
String strParameter = this.getParameter("number");
if (strParameter == null)
strParameter = strDefault;
g.drawString(strParameter, 10, 10);
}
}

谁能告诉我在 param 标签和 html 之间传递和检索值的代码?

最佳答案

我认为您可以像这样从 javascript 对象指定参数:

<applet code="Calc.class" width="100" height="100">
<param name="number" id="parm" value="&{num};">
</applet>

但是,我不确定与 IE 的兼容性,因此您可能必须document.write 出您的 applet 代码,注入(inject)相应的参数值,如下所示:

<head>
<script type="text/javascript">
var num;

function getVal() {
num = document.getElementById('in').value;

writeAppletTags();
}

function writeAppletTags() {
var container = document.getElementById("applet-container");

container.innerHTML = "<applet code=\"Calc.class\" width=\"100\" height=\"100\">";
container.innerHTML += "<param name=\"number\" value=\"" + num + "\">";
container.innerHTML += "</applet>";
}
</script>
</head>
<body>
Number : <input type="text" id="in" ><br/>
<button id="myBtn" onclick="getVal()">Try it</button><br/>
<div id="applet-container" />
</body>

从 Java 发送 POST

正如我在评论中所说,这有点复杂。您必须将您的值发布(您也可以使用 GET)到托管文件(可以是任何服务器端脚本技术)。下面演示了这一点,code taken from here .

URL url;
URLConnection urlConnection;
DataOutputStream outStream;
DataInputStream inStream;

// Build request body
String body = "key=value";

// Create connection
url = new URL("http://myhostedurl.com/receiving-page.php");
urlConnection = url.openConnection();
((HttpURLConnection)urlConnection).setRequestMethod("POST");
urlConnection.setDoInput(true);
urlConnection.setDoOutput(true);
urlConnection.setUseCaches(false);
urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
urlConnection.setRequestProperty("Content-Length", ""+ body.length());

// Create I/O streams
outStream = new DataOutputStream(urlConnection.getOutputStream());
inStream = new DataInputStream(urlConnection.getInputStream());

// Send request
outStream.writeBytes(body);
outStream.flush();
outStream.close();

// Close I/O streams
inStream.close();
outStream.close();

关于javascript - 如何将值从 HTML 页面传递到 Java 小程序?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/12585022/

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