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//
// ========================================================================
// Copyright (c) 1995 Mort Bay Consulting Pty Ltd and others.
//
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License v. 2.0 which is available at
// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
// which is available at https://www.apache.org/licenses/LICENSE-2.0.
//
// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
// ========================================================================
//
package org.eclipse.jetty.ee8.nested;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.atomic.AtomicReference;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.eclipse.jetty.util.ArrayUtil;
import org.eclipse.jetty.util.ExceptionUtil;
import org.eclipse.jetty.util.annotation.ManagedAttribute;
import org.eclipse.jetty.util.annotation.ManagedObject;
/**
* A collection of handlers.
*
* The default implementations calls all handlers in list order,
* regardless of the response status or exceptions. Derived implementation
* may alter the order or the conditions of calling the contained
* handlers.
*/
@ManagedObject("Handler of multiple handlers")
public class HandlerCollection extends AbstractHandlerContainer {
private final boolean _mutableWhenRunning;
protected final AtomicReference _handlers = new AtomicReference<>();
public HandlerCollection() {
this(false);
}
public HandlerCollection(Handler... handlers) {
this(false, handlers);
}
public HandlerCollection(boolean mutableWhenRunning, Handler... handlers) {
_mutableWhenRunning = mutableWhenRunning;
if (handlers.length > 0)
setHandlers(handlers);
}
/**
* @return the array of handlers.
*/
@Override
@ManagedAttribute(value = "Wrapped handlers", readonly = true)
public Handler[] getHandlers() {
Handlers handlers = _handlers.get();
return handlers == null ? null : handlers._handlers;
}
/**
* Set the array of handlers to set..
* @param handlers the array of handlers to set.
*/
public void setHandlers(Handler[] handlers) {
if (!_mutableWhenRunning && isStarted())
throw new IllegalStateException(getState());
while (true) {
if (updateHandlers(_handlers.get(), newHandlers(handlers)))
break;
}
}
protected Handlers newHandlers(Handler[] handlers) {
if (handlers == null || handlers.length == 0)
return null;
return new Handlers(handlers);
}
protected boolean updateHandlers(Handlers old, Handlers handlers) {
if (handlers != null) {
// check for loops
for (Handler handler : handlers._handlers) {
if (handler == this || (handler instanceof HandlerContainer && Arrays.asList(((HandlerContainer) handler).getChildHandlers()).contains(this)))
throw new IllegalStateException("setHandler loop");
}
// Set server
for (Handler handler : handlers._handlers) {
if (handler.getServer() != getServer())
handler.setServer(getServer());
}
}
if (_handlers.compareAndSet(old, handlers)) {
Handler[] oldBeans = old == null ? null : old._handlers;
Handler[] newBeans = handlers == null ? null : handlers._handlers;
updateBeans(oldBeans, newBeans);
return true;
}
return false;
}
@Override
public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
if (isStarted()) {
Handlers handlers = _handlers.get();
if (handlers == null)
return;
Throwable errors = null;
for (Handler handler : handlers._handlers) {
try {
handler.handle(target, baseRequest, request, response);
} catch (IOException | RuntimeException e) {
throw e;
} catch (Exception e) {
errors = ExceptionUtil.combine(errors, e);
}
}
if (errors instanceof IOException ioException)
throw ioException;
ExceptionUtil.ifExceptionThrowAs(ServletException.class, errors);
}
}
/**
* Adds a handler.
* This implementation adds the passed handler to the end of the existing collection of handlers.
* If the handler is already added, it is removed and readded
*/
public void addHandler(Handler handler) {
while (true) {
Handlers old = _handlers.get();
Handlers handlers = newHandlers(ArrayUtil.addToArray(old == null ? null : ArrayUtil.removeFromArray(old._handlers, handler), handler, Handler.class));
if (updateHandlers(old, handlers))
break;
}
}
/**
* Prepends a handler.
* This implementation adds the passed handler to the start of the existing collection of handlers.
*/
public void prependHandler(Handler handler) {
while (true) {
Handlers old = _handlers.get();
Handlers handlers = newHandlers(ArrayUtil.prependToArray(handler, old == null ? null : old._handlers, Handler.class));
if (updateHandlers(old, handlers))
break;
}
}
public void removeHandler(Handler handler) {
while (true) {
Handlers old = _handlers.get();
if (old == null || old._handlers.length == 0)
break;
Handlers handlers = newHandlers(ArrayUtil.removeFromArray(old._handlers, handler));
if (updateHandlers(old, handlers))
break;
}
}
@Override
protected void expandChildren(List list, Class byClass) {
Handler[] handlers = getHandlers();
if (handlers != null)
for (Handler h : handlers) {
expandHandler(h, list, byClass);
}
}
@Override
public void destroy() {
if (!isStopped())
throw new IllegalStateException("!STOPPED");
Handler[] children = getChildHandlers();
setHandlers(null);
for (Handler child : children) {
child.destroy();
}
super.destroy();
}
protected static class Handlers {
private final Handler[] _handlers;
protected Handlers(Handler[] handlers) {
this._handlers = handlers;
}
public Handler[] getHandlers() {
return _handlers;
}
}
}