这是我原帖的延续：javascript-to-java-applet-using-deployjava-js-to-run-commandline
我对Java很新 . 我想创建一个Java Applet，它允许我的JavaScript将命令行传递给Java Applet . 这只会在我的开发机器上运行 - 无需提醒我安全问题是什么 . 用例是我的ExtJS应用程序有一个introspector，允许我显示类 . 我希望能够单击一个类，将相关的路径名传递给Applet，并在Eclipse中打开该文件进行编辑 .
经过多次失败的测试后，这就是我发现的作品 . 感谢Andrew Thompson以及下面提到的其他人 .
似乎有两条路径，我设法让它们都工作 . 我把它们都包括在这里 . 路径1是执行带参数的程序（例如 D:/Eclipse/eclipse.exe --launcher.openFile C:/sites/test.js ），路径2是设置Win7以在打开* .js文件时打开Eclipse（即将* .js与Eclipse关联） .
安全免责声明：请记住，路径1在公共服务器上是完全不安全的 - 通过JavaScript传递格式或删除命令或任何其他恶作剧相对容易！
对于像我这样的Java新手，我将尽可能明确地了解这些步骤 .
执行程序的类 . 谢谢你：https://stackoverflow.com/users/80389/corgrath
package systemcmd;
import java.applet.Applet;
import java.io.*;
public class Runcmd extends Applet {
private static final long serialVersionUID = 1L;
public void init() {
// It seems that even though this command is not executed when the
// applet is run via JS we still need to refer to the exec command here,
// I presume so it is linked? If I comment these out altogether, the
// applet doesnt work. Either of the following will suffice.
// FYI. Just betraying my Java newbie status! :-)
//exec("notepad c:/sites/test.txt");
exec("calc");
}
// From https://stackoverflow.com/questions/1068271/signed-applet-gives-accesscontrolexception-access-denied-when-calling-from-jav
// Thank you !!!
public void exec(String command) {
try {
// launch EXE and grab stdin/stdout and stderr
Process process = Runtime.getRuntime().exec(getParameter("command"));
// OutputStream stdin = process.getOutputStream();
InputStream stderr = process.getErrorStream();
InputStream stdout = process.getInputStream();
// clean up if any output in stdout
String line = "";
BufferedReader brCleanUp = new BufferedReader(new InputStreamReader(stdout));
while ((line = brCleanUp.readLine()) != null) {
//System.out.println ("[Stdout] " + line);
}
brCleanUp.close();
// clean up if any output in stderr
brCleanUp = new BufferedReader(new InputStreamReader(stderr));
while ((line = brCleanUp.readLine()) != null) {
//System.out.println ("[Stderr] " + line);
}
brCleanUp.close();
} catch (Exception exception) {
exception.printStackTrace();
}
}
}
用于运行与文件关联的程序的类：
package systemcmd;
import java.applet.Applet;
import java.awt.Desktop;
import java.io.*;
public class Launchapp extends Applet {
private static final long serialVersionUID = 1L;
public void init() {
// It seems that even though this command is not executed when the
// applet is run via JS we still need to refer to the exec command here,
// I presume so it is linked? If I comment these out altogether, the
// applet doesnt work. Either of the following will suffice.
// FYI. Just betraying my Java newbie status! :-)
//launch("notepad c:/sites/test.txt");
launch("calc");
}
// From https://stackoverflow.com/questions/1068271/signed-applet-gives-accesscontrolexception-access-denied-when-calling-from-jav
// Thank you !!!
public void launch(String command) {
try {
Desktop.getDesktop().open(new File(getParameter("command")));
} catch (Exception exception) {
exception.printStackTrace();
}
}
}
使用Eclipse，我将这两个类导出到一个名为runcombo.jar的jar文件中，该文件位于与以下HTML文件相同的文件夹中 . 然后，我自己签署了安全问题所必需的 jar . 我发现本教程对该过程很有帮助 . http://www.jade-cheng.com/uh/ta/signed-applet-tutorial/ .
HTML和JavaScript测试页面：
<html>
<head>
<script type="text/javascript">
function exec( command ) {
var applet = "<object type='application/x-java-applet' height='100' width='100' name='jsApplet'><param name='code' value='systemcmd.Runcmd'/><param name='archive' value='runcombo.jar' /><param name='mayscript' value='true'/><param name='command' value='" + command + "'/>Applet failed to run. No Java plug-in was found.</object>";
var body = document.getElementsByTagName("body")[0];
var div = document.createElement("div");
div.innerHTML = applet;
body.appendChild(div);
}
function launch( command ) {
var applet = "<object type='application/x-java-applet' height='100' width='100' name='jsApplet'><param name='code' value='systemcmd.Launchapp'/><param name='archive' value='runcombo.jar' /><param name='mayscript' value='true'/><param name='command' value='" + command + "'/>Applet failed to run. No Java plug-in was found.</object>";
var body = document.getElementsByTagName("body")[0];
var div = document.createElement("div");
div.innerHTML = applet;
body.appendChild(div);
}
</script>
</head>
<body>
<a href="#" onclick="exec('notepad c:/sites/test.txt');">Exec Notepad</a>
<br> <a href="#" onclick="exec('calc');">Exec Calculator</a>
<br> <a href="#" onclick="exec('D:/Eclipse/eclipse.exe --launcher.openFile C:/sites/test.js');">Exec Eclipse with command line parms</a>
<br> <a href="#" onclick="launch('C:/sites/test2.txt');">Launch Notepad via *.txt association</a>
<br> <a href="#" onclick="launch('C:/sites/test2.js');">Launch Eclipse via *.js association</a>
</body>
</html>
请注意，在调用JS函数时，applet会添加到DOM中 . 这是使用Java安全性的一部分，避免了上述阻止applet运行的安全问题 . 另请注意，有两个JS函数调用来匹配不同的类 .
再次感谢帮助我实现这一目标的所有人 . 现在我可以回到最初的目的 - 完成我的Ext Introspector！
穆雷
1 回答
你不需要每次都创建一个新的applet实例，使用applet的mayscript标签，你可以告诉浏览器允许java脚本进行applet通信 .
你也应该清理init方法
Ref http://help.dottoro.com/lhbkaqko.php和http://docs.oracle.com/javase/6/docs/technotes/guides/plugin/developer_guide/java_js.html旧的netscape类是每个JVM（netscape.javascript）的一部分 .