我正在尝试从我开发的 Java 签名 Applet 内部调用 Javascript 函数。当我使用带有 Sun Java 插件的浏览器时,效果非常好。我在 Windows 7 和 Ubuntu 10.04 上使用 Firefox、Chrome 和 Internet Explorer (Windows) 浏览器进行了测试。
当我尝试在带有 Iced Tea 插件的任何浏览器上运行相同的代码时,会出现以下错误:
<小时/><小时/>net.sourceforge.jnlp.LaunchException: Fatal: Initialization Error: Could not initialize applet. at net.sourceforge.jnlp.Launcher.createApplet(Launcher.java:735) at net.sourceforge.jnlp.Launcher.getApplet(Launcher.java:676) at net.sourceforge.jnlp.Launcher$TgThread.run(Launcher.java:886)Caused by: java.lang.NullPointerException at net.sourceforge.jnlp.runtime.JNLPClassLoader.getPermissions(JNLPClassLoader.java:915) at java.security.SecureClassLoader.getProtectionDomain(SecureClassLoader.java:206) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:447) at java.net.URLClassLoader.access$100(URLClassLoader.java:71) at java.net.URLClassLoader$1.run(URLClassLoader.java:361) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at net.sourceforge.jnlp.runtime.JNLPClassLoader.findClass(JNLPClassLoader.java:1499) at net.sourceforge.jnlp.runtime.JNLPClassLoader.loadClassExt(JNLPClassLoader.java:1526) at net.sourceforge.jnlp.runtime.JNLPClassLoader.loadClass(JNLPClassLoader.java:1341) at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2442) at java.lang.Class.getDeclaredMethod(Class.java:1952) at java.awt.Component.isCoalesceEventsOverriden(Component.java:6190) at java.awt.Component.access$500(Component.java:188) at java.awt.Component$3.run(Component.java:6144) at java.awt.Component$3.run(Component.java:6142) at java.security.AccessController.doPrivileged(Native Method) at java.awt.Component.checkCoalescing(Component.java:6141) at java.awt.Component.(Component.java:6110) at java.awt.Container.(Container.java:276) at java.awt.Panel.(Panel.java:64) at java.awt.Panel.(Panel.java:56) at java.applet.Applet.(Applet.java:65) at javax.swing.JApplet.(JApplet.java:130) at br.ufrj.land.tangram.measures.NetworkMeasurerApplet.(NetworkMeasurerApplet.java:11) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:525) at java.lang.Class.newInstance0(Class.java:372) at java.lang.Class.newInstance(Class.java:325) at net.sourceforge.jnlp.Launcher.createApplet(Launcher.java:726) ... 2 more Caused by: java.lang.NullPointerException at net.sourceforge.jnlp.runtime.JNLPClassLoader.getPermissions(JNLPClassLoader.java:915) at java.security.SecureClassLoader.getProtectionDomain(SecureClassLoader.java:206) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:447) at java.net.URLClassLoader.access$100(URLClassLoader.java:71) at java.net.URLClassLoader$1.run(URLClassLoader.java:361) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at net.sourceforge.jnlp.runtime.JNLPClassLoader.findClass(JNLPClassLoader.java:1499) at net.sourceforge.jnlp.runtime.JNLPClassLoader.loadClassExt(JNLPClassLoader.java:1526) at net.sourceforge.jnlp.runtime.JNLPClassLoader.loadClass(JNLPClassLoader.java:1341) at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2442) at java.lang.Class.getDeclaredMethod(Class.java:1952) at java.awt.Component.isCoalesceEventsOverriden(Component.java:6190) at java.awt.Component.access$500(Component.java:188) at java.awt.Component$3.run(Component.java:6144) at java.awt.Component$3.run(Component.java:6142) at java.security.AccessController.doPrivileged(Native Method) at java.awt.Component.checkCoalescing(Component.java:6141) at java.awt.Component.(Component.java:6110) at java.awt.Container.(Container.java:276) at java.awt.Panel.(Panel.java:64) at java.awt.Panel.(Panel.java:56) at java.applet.Applet.(Applet.java:65) at javax.swing.JApplet.(JApplet.java:130) at br.ufrj.land.tangram.measures.NetworkMeasurerApplet.(NetworkMeasurerApplet.java:11) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:525) at java.lang.Class.newInstance0(Class.java:372) at java.lang.Class.newInstance(Class.java:325) at net.sourceforge.jnlp.Launcher.createApplet(Launcher.java:726) at net.sourceforge.jnlp.Launcher.getApplet(Launcher.java:676) at net.sourceforge.jnlp.Launcher$TgThread.run(Launcher.java:886)java.lang.NullPointerException at net.sourceforge.jnlp.NetxPanel.runLoader(NetxPanel.java:154) at sun.applet.AppletPanel.run(AppletPanel.java:379) at java.lang.Thread.run(Thread.java:722) java.lang.NullPointerException at sun.applet.AppletPanel.run(AppletPanel.java:429) at java.lang.Thread.run(Thread.java:722)
我尝试过的配置和事情:
我与 Iced Tea 插件一起使用的 Linux 版本是 Ubuntu 12.04
我尝试使用 Sun JDK 6 和 7 以及 Open JDK 6 和 7 编译代码,但在浏览器上使用 Iced Tea 插件时均失败。
我用 Iced Tea 版本 6 和版本 7 尝试了我的代码
我在 Ubuntu 上使用 Firefox 和 Chrome 浏览器尝试了我的代码
代码片段:
HTML(正文标记内):
<!-- JavaScript File That Contains My Javascript Function -->
<script type="text/javascript" src="./my_javascript_file.js"></script>
<!-- Applet That Will Call My Javascript Function -->
<object height="1" width="1" id="MyApplet" name="MyApplet"
java_version="1.5+" type="application/x-java-applet">
<param name="code" value="foo.MyApplet" />
<param name="archive" value="MyApplet.jar" />
<param name="JVM_PARAM" value="-Djava.security.policy=applet.policy" />
<param name="mayscript" value="true" />
<param name="scriptable" value="true" />
<param name="name" value="MyApplet" />
</object>
我尝试调用的 Javascript 方法(在 my_javascript_file.js 中):
window.performAppletCode = function (parameter_1) {
//Function code
}
“MyApplet.jar”内的Java applet代码(相关部分):
package foo;
import java.util.Arrays;
import javax.swing.JApplet;
import netscape.javascript.JSException;
import netscape.javascript.JSObject;
public class MyApplet extends JApplet {
//Parameter that will be sent to Javascript function
public String parameter_1;
//JSObject that will be responsible for accessing javascript on my page
public JSObject window = null;
private Thread myThread;
private ImportantClass importantClassInstance;
@Override
public void init() {
}
@Override
public void start() {
if (this.window == null) {
try {
this.window = JSObject.getWindow(this);
if (this.window == null){
System.out.println("Window is null");
}
}
catch (JSException jse) {
jse.printStackTrace();
}
fooStart();
}
}
public void fooStart() {
importantClassInstance = new ImportantClass();
// MyThread Section
myThread = new Thread(new Runnable() {
@Override
public void run() {
// Run latency test.
int[] fooArray = importantClassInstance.fooMethod();
parameter_1 = Arrays.toString(fooArray);
//Javascript function call
window.call("performAppletCode", new Object[] {parameter_1});
}
});
myThread.start();
}
}
我的小程序使用 jarsigner 进行签名,并且证书包含在我的 HTML 目录中。
如果有人知道解决此问题的可能线索,请告诉我。
谢谢, 吉列尔梅。
最佳答案
当从 JS 调用时,小程序会失去信任。要解决此问题,请参阅 AccessController.doPrivileged(...)
和 this answer .
关于java - 使用 Javascript 函数调用签名的小程序 : Initialization Error on IcedTea plugin,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/11533235/