这是我原来的帖子的延续：javascript-to-java-applet-using-deployjava-js-to-run-commandline
我对Java很陌生。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 - 无需提醒我这是一个安全问题。用例是我的 ExtJS 应用程序有一个内省器，它允许我显示类。我希望能够单击一个类，将相关路径名传递给 Applet 并在 Eclipse 中打开该文件进行编辑。
经过多次失败的测试后，我发现这是可行的。感谢Andrew Thompson和下面提到的其他人。
似乎有两条路，我设法让它们都工作。我把它们都包括在这里。路径 1 是执行带有参数的程序（例如D:/Eclipse/eclipse.exe --launcher.openFile C:/sites/test.js），路径 2 是设置 Win7 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，我将尽可能明确地说明这些步骤。
执行程序的类。谢谢：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。然后我对 jar 进行了自我签名，这也是安全问题所必需的。我发现本教程对这个过程很有帮助。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，当调用 JS 函数时，小程序会添加到 DOM。这是使用 Java 安全性的一部分，并避免了上述阻止小程序运行的安全性问题。另请注意，有两个 JS 函数调用来匹配不同的类。
再次感谢所有帮助我完成这项工作的人。现在我可以回到最初的目的——完成我的 Ext Introspector！
默里