/**
* Instantiate a JavaBean.
*
* @param classLoader the class-loader from which we should create the bean. If this is null, then
* the system class-loader is used.
* @param beanName the name of the bean within the class-loader. For example "sun.beanbox.foobah"
* @exception java.lang.ClassNotFoundException if the class of a serialized object could not be
* found.
* @exception java.io.IOException if an I/O error occurs.
*/
public static Object instantiate(ClassLoader cls, String beanName)
throws java.io.IOException, ClassNotFoundException {
java.io.InputStream ins;
java.io.ObjectInputStream oins = null;
Object result = null;
boolean serialized = false;
java.io.IOException serex = null;
// If the given classloader is null, we check if an
// system classloader is available and (if so)
// use that instead.
// Note that calls on the system class loader will
// look in the bootstrap class loader first.
if (cls == null) {
try {
cls = ClassLoader.getSystemClassLoader();
} catch (SecurityException ex) { // We're not allowed to access the system class loader.
// Drop through.
}
}
// Try to find a serialized object with this name
final String serName = beanName.replace('.', '/').concat(".ser");
final ClassLoader loader = cls;
ins =
(InputStream)
java.security.AccessController.doPrivileged(
new java.security.PrivilegedAction() {
public Object run() {
if (loader == null) return ClassLoader.getSystemResourceAsStream(serName);
else return loader.getResourceAsStream(serName);
}
});
if (ins != null) {
try {
if (cls == null) {
oins = new ObjectInputStream(ins);
} else {
oins = new ObjectInputStreamWithLoader(ins, cls);
}
result = oins.readObject();
serialized = true;
oins.close();
} catch (java.io.IOException ex) {
ins.close();
// Drop through and try opening the class. But remember
// the exception in case we can't find the class either.
serex = ex;
} catch (ClassNotFoundException ex) {
ins.close();
throw ex;
}
}
if (result == null) {
// No serialized object, try just instantiating the class
Class cl;
try {
if (cls == null) {
cl = Class.forName(beanName);
} else {
cl = cls.loadClass(beanName);
}
} catch (ClassNotFoundException ex) {
// There is no appropriate class. If we earlier tried to
// deserialize an object and got an IO exception, throw that,
// otherwise rethrow the ClassNotFoundException.
if (serex != null) {
throw serex;
}
throw ex;
}
/*
* Try to instantiate the class.
*/
try {
result = cl.newInstance();
} catch (Exception ex) {
// We have to remap the exception to one in our signature.
// But we pass extra information in the detail message.
throw new ClassNotFoundException("" + cl + " : " + ex);
}
}
if (result != null) { // Ok, if the result is an applet initialize it.
AppletStub stub = null;
if (result instanceof Applet) {
Applet applet = (Applet) result;
// Figure our the codebase and docbase URLs. We do this
// by locating the URL for a known resource, and then
// massaging the URL.
// First find the "resource name" corresponding to the bean
// itself. So a serialzied bean "a.b.c" would imply a
// resource name of "a/b/c.ser" and a classname of "x.y"
// would imply a resource name of "x/y.class".
final String resourceName;
if (serialized) {
// Serialized bean
resourceName = beanName.replace('.', '/').concat(".ser");
} else {
// Regular class
resourceName = beanName.replace('.', '/').concat(".class");
}
URL objectUrl = null;
URL codeBase = null;
URL docBase = null;
// Now get the URL correponding to the resource name.
final ClassLoader cloader = cls;
objectUrl =
(URL)
java.security.AccessController.doPrivileged(
new java.security.PrivilegedAction() {
public Object run() {
if (cloader == null) return ClassLoader.getSystemResource(resourceName);
else return cloader.getResource(resourceName);
}
});
// If we found a URL, we try to locate the docbase by taking
// of the final path name component, and the code base by taking
// of the complete resourceName.
// So if we had a resourceName of "a/b/c.class" and we got an
// objectURL of "file://bert/classes/a/b/c.class" then we would
// want to set the codebase to "file://bert/classes/" and the
// docbase to "file://bert/classes/a/b/"
if (objectUrl != null) {
String s = objectUrl.toExternalForm();
if (s.endsWith(resourceName)) {
int ix = s.length() - resourceName.length();
codeBase = new URL(s.substring(0, ix));
docBase = codeBase;
ix = s.lastIndexOf('/');
if (ix >= 0) {
docBase = new URL(s.substring(0, ix + 1));
}
}
}
// Setup a default context and stub.
BeansAppletContext context = new BeansAppletContext(applet);
stub = (AppletStub) new BeansAppletStub(applet, context, codeBase, docBase);
applet.setStub(stub);
// If it was deserialized then it was already init-ed.
// Otherwise we need to initialize it.
if (!serialized) {
// We need to set a reasonable initial size, as many
// applets are unhappy if they are started without
// having been explicitly sized.
applet.setSize(100, 100);
applet.init();
}
((BeansAppletStub) stub).active = true;
}
}
return result;
}
/**
* Execute applet events. Here is the state transition diagram
*
* <pre>{@literal
* Note: (XXX) is the action
* APPLET_XXX is the state
* (applet code loaded) --> APPLET_LOAD -- (applet init called)--> APPLET_INIT --
* (applet start called) --> APPLET_START -- (applet stop called) --> APPLET_STOP --
* (applet destroyed called) --> APPLET_DESTROY --> (applet gets disposed) -->
* APPLET_DISPOSE --> ...
* }</pre>
*
* In the legacy lifecycle model. The applet gets loaded, inited and started. So it stays in the
* APPLET_START state unless the applet goes away(refresh page or leave the page). So the applet
* stop method called and the applet enters APPLET_STOP state. Then if the applet is revisited, it
* will call applet start method and enter the APPLET_START state and stay there.
*
* <p>In the modern lifecycle model. When the applet first time visited, it is same as legacy
* lifecycle model. However, when the applet page goes away. It calls applet stop method and
* enters APPLET_STOP state and then applet destroyed method gets called and enters APPLET_DESTROY
* state.
*
* <p>This code is also called by AppletViewer. In AppletViewer "Restart" menu, the applet is jump
* from APPLET_STOP to APPLET_DESTROY and to APPLET_INIT .
*
* <p>Also, the applet can jump from APPLET_INIT state to APPLET_DESTROY (in Netscape/Mozilla
* case). Same as APPLET_LOAD to APPLET_DISPOSE since all of this are triggered by browser.
*/
@Override
public void run() {
Thread curThread = Thread.currentThread();
if (curThread == loaderThread) {
// if we are in the loader thread, cause
// loading to occur. We may exit this with
// status being APPLET_DISPOSE, APPLET_ERROR,
// or APPLET_LOAD
runLoader();
return;
}
boolean disposed = false;
while (!disposed && !curThread.isInterrupted()) {
AppletEvent evt;
try {
evt = getNextEvent();
} catch (InterruptedException e) {
showAppletStatus("bail");
return;
}
// showAppletStatus("EVENT = " + evt.getID());
try {
switch (evt.getID()) {
case APPLET_LOAD:
if (!okToLoad()) {
break;
}
// This complexity allows loading of applets to be
// interruptable. The actual thread loading runs
// in a separate thread, so it can be interrupted
// without harming the applet thread.
// So that we don't have to worry about
// concurrency issues, the main applet thread waits
// until the loader thread terminates.
// (one way or another).
if (loaderThread == null) {
setLoaderThread(new Thread(null, this, "AppletLoader", 0, false));
loaderThread.start();
// we get to go to sleep while this runs
loaderThread.join();
setLoaderThread(null);
} else {
// REMIND: issue an error -- this case should never
// occur.
}
break;
case APPLET_INIT:
// AppletViewer "Restart" will jump from destroy method to
// init, that is why we need to check status w/ APPLET_DESTROY
if (status != APPLET_LOAD && status != APPLET_DESTROY) {
showAppletStatus("notloaded");
break;
}
applet.resize(defaultAppletSize);
if (PerformanceLogger.loggingEnabled()) {
PerformanceLogger.setTime("Applet Init");
PerformanceLogger.outputLog();
}
applet.init();
// Need the default(fallback) font to be created in this AppContext
Font f = getFont();
if (f == null
|| "dialog".equals(f.getFamily().toLowerCase(Locale.ENGLISH))
&& f.getSize() == 12
&& f.getStyle() == Font.PLAIN) {
setFont(new Font(Font.DIALOG, Font.PLAIN, 12));
}
// Validate the applet in event dispatch thread
// to avoid deadlock.
try {
final AppletPanel p = this;
Runnable r =
new Runnable() {
@Override
public void run() {
p.validate();
}
};
AWTAccessor.getEventQueueAccessor().invokeAndWait(applet, r);
} catch (InterruptedException ie) {
} catch (InvocationTargetException ite) {
}
status = APPLET_INIT;
showAppletStatus("inited");
break;
case APPLET_START:
{
if (status != APPLET_INIT && status != APPLET_STOP) {
showAppletStatus("notinited");
break;
}
applet.resize(currentAppletSize);
applet.start();
// Validate and show the applet in event dispatch thread
// to avoid deadlock.
try {
final AppletPanel p = this;
final Applet a = applet;
Runnable r =
new Runnable() {
@Override
public void run() {
p.validate();
a.setVisible(true);
// Fix for BugTraq ID 4041703.
// Set the default focus for an applet.
if (hasInitialFocus()) {
setDefaultFocus();
}
}
};
AWTAccessor.getEventQueueAccessor().invokeAndWait(applet, r);
} catch (InterruptedException ie) {
} catch (InvocationTargetException ite) {
}
status = APPLET_START;
showAppletStatus("started");
break;
}
case APPLET_STOP:
if (status != APPLET_START) {
showAppletStatus("notstarted");
break;
}
status = APPLET_STOP;
// Hide the applet in event dispatch thread
// to avoid deadlock.
try {
final Applet a = applet;
Runnable r =
new Runnable() {
@Override
public void run() {
a.setVisible(false);
}
};
AWTAccessor.getEventQueueAccessor().invokeAndWait(applet, r);
} catch (InterruptedException ie) {
} catch (InvocationTargetException ite) {
}
// During Applet.stop(), any AccessControlException on an involved Class remains in
// the "memory" of the AppletClassLoader. If the same instance of the ClassLoader is
// reused, the same exception will occur during class loading. Set the
// AppletClassLoader's
// exceptionStatusSet flag to allow recognition of what had happened
// when reusing AppletClassLoader object.
try {
applet.stop();
} catch (java.security.AccessControlException e) {
setExceptionStatus(e);
// rethrow exception to be handled as it normally would be.
throw e;
}
showAppletStatus("stopped");
break;
case APPLET_DESTROY:
if (status != APPLET_STOP && status != APPLET_INIT) {
showAppletStatus("notstopped");
break;
}
status = APPLET_DESTROY;
// During Applet.destroy(), any AccessControlException on an involved Class remains in
// the "memory" of the AppletClassLoader. If the same instance of the ClassLoader is
// reused, the same exception will occur during class loading. Set the
// AppletClassLoader's
// exceptionStatusSet flag to allow recognition of what had happened
// when reusing AppletClassLoader object.
try {
applet.destroy();
} catch (java.security.AccessControlException e) {
setExceptionStatus(e);
// rethrow exception to be handled as it normally would be.
throw e;
}
showAppletStatus("destroyed");
break;
case APPLET_DISPOSE:
if (status != APPLET_DESTROY && status != APPLET_LOAD) {
showAppletStatus("notdestroyed");
break;
}
status = APPLET_DISPOSE;
try {
final Applet a = applet;
Runnable r =
new Runnable() {
@Override
public void run() {
remove(a);
}
};
AWTAccessor.getEventQueueAccessor().invokeAndWait(applet, r);
} catch (InterruptedException ie) {
} catch (InvocationTargetException ite) {
}
applet = null;
showAppletStatus("disposed");
disposed = true;
break;
case APPLET_QUIT:
return;
}
} catch (Exception e) {
status = APPLET_ERROR;
if (e.getMessage() != null) {
showAppletStatus("exception2", e.getClass().getName(), e.getMessage());
} else {
showAppletStatus("exception", e.getClass().getName());
}
showAppletException(e);
} catch (ThreadDeath e) {
showAppletStatus("death");
return;
} catch (Error e) {
status = APPLET_ERROR;
if (e.getMessage() != null) {
showAppletStatus("error2", e.getClass().getName(), e.getMessage());
} else {
showAppletStatus("error", e.getClass().getName());
}
showAppletException(e);
}
clearLoadAbortRequest();
}
}