/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2014 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package io.undertow.servlet.core;

import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Date;
import java.util.List;
import java.util.concurrent.atomic.AtomicLongFieldUpdater;

import javax.servlet.MultipartConfigElement;
import javax.servlet.Servlet;
import javax.servlet.ServletException;
import javax.servlet.SingleThreadModel;
import javax.servlet.UnavailableException;

import io.undertow.server.handlers.form.FormEncodedDataDefinition;
import io.undertow.server.handlers.form.FormParserFactory;
import io.undertow.server.handlers.form.MultiPartParserDefinition;
import io.undertow.server.handlers.resource.ResourceChangeListener;
import io.undertow.server.handlers.resource.ResourceManager;
import io.undertow.servlet.UndertowServletLogger;
import io.undertow.servlet.UndertowServletMessages;
import io.undertow.servlet.api.DeploymentInfo;
import io.undertow.servlet.api.DeploymentManager;
import io.undertow.servlet.api.InstanceFactory;
import io.undertow.servlet.api.InstanceHandle;
import io.undertow.servlet.api.LifecycleInterceptor;
import io.undertow.servlet.api.ServletInfo;
import io.undertow.servlet.spec.ServletConfigImpl;
import io.undertow.servlet.spec.ServletContextImpl;

Manager for a servlets lifecycle.
Author:Stuart Douglas
/** * Manager for a servlets lifecycle. * * @author Stuart Douglas */
public class ManagedServlet implements Lifecycle { private final ServletInfo servletInfo; private final ServletContextImpl servletContext; private volatile boolean started = false; private final InstanceStrategy instanceStrategy; private volatile boolean permanentlyUnavailable = false; private long maxRequestSize; private FormParserFactory formParserFactory; private MultipartConfigElement multipartConfig; private static final AtomicLongFieldUpdater<ManagedServlet> unavailableUntilUpdater = AtomicLongFieldUpdater.newUpdater(ManagedServlet.class, "unavailableUntil"); @SuppressWarnings("unused") private volatile long unavailableUntil = 0; public ManagedServlet(final ServletInfo servletInfo, final ServletContextImpl servletContext) { this.servletInfo = servletInfo; this.servletContext = servletContext; if (SingleThreadModel.class.isAssignableFrom(servletInfo.getServletClass())) { instanceStrategy = new SingleThreadModelPoolStrategy(servletInfo.getInstanceFactory(), servletInfo, servletContext); } else { instanceStrategy = new DefaultInstanceStrategy(servletInfo.getInstanceFactory(), servletInfo, servletContext); } setupMultipart(servletContext); } public void setupMultipart(ServletContextImpl servletContext) { FormEncodedDataDefinition formDataParser = new FormEncodedDataDefinition() .setDefaultEncoding(servletContext.getDeployment().getDefaultRequestCharset().name()); MultipartConfigElement multipartConfig = servletInfo.getMultipartConfig(); if(multipartConfig == null) { multipartConfig = servletContext.getDeployment().getDeploymentInfo().getDefaultMultipartConfig(); } this.multipartConfig = multipartConfig; if (multipartConfig != null) { //todo: fileSizeThreshold MultipartConfigElement config = multipartConfig; if (config.getMaxRequestSize() != -1) { maxRequestSize = config.getMaxRequestSize(); } else { maxRequestSize = -1; } final Path tempDir; if(config.getLocation() == null || config.getLocation().isEmpty()) { tempDir = servletContext.getDeployment().getDeploymentInfo().getTempPath(); } else { String location = config.getLocation(); Path locFile = Paths.get(location); if(locFile.isAbsolute()) { tempDir = locFile; } else { final DeploymentInfo deploymentInfo = servletContext.getDeployment().getDeploymentInfo(); tempDir = deploymentInfo.requireTempPath().resolve(location); } } MultiPartParserDefinition multiPartParserDefinition = new MultiPartParserDefinition(tempDir); if(config.getMaxFileSize() > 0) { multiPartParserDefinition.setMaxIndividualFileSize(config.getMaxFileSize()); } if (config.getFileSizeThreshold() > 0) { multiPartParserDefinition.setFileSizeThreshold(config.getFileSizeThreshold()); } multiPartParserDefinition.setDefaultEncoding(servletContext.getDeployment().getDefaultRequestCharset().name()); formParserFactory = FormParserFactory.builder(false) .addParser(formDataParser) .addParser(multiPartParserDefinition) .build(); } else { //no multipart config we don't allow multipart requests formParserFactory = FormParserFactory.builder(false).addParser(formDataParser).build(); maxRequestSize = -1; } } public synchronized void start() throws ServletException { } public void createServlet() throws ServletException { if (permanentlyUnavailable) { return; } try { if (!started && servletInfo.getLoadOnStartup() != null && servletInfo.getLoadOnStartup() >= 0) { instanceStrategy.start(); started = true; } } catch (UnavailableException e) { if (e.isPermanent()) { permanentlyUnavailable = true; stop(); } } } public synchronized void stop() { if (started) { instanceStrategy.stop(); } started = false; } @Override public boolean isStarted() { return started; } public boolean isPermanentlyUnavailable() { return permanentlyUnavailable; } public boolean isTemporarilyUnavailable() { long until = unavailableUntil; if (until != 0) { if (System.currentTimeMillis() < until) { return true; } else { unavailableUntilUpdater.compareAndSet(this, until, 0); } } return false; } public void setPermanentlyUnavailable(final boolean permanentlyUnavailable) { this.permanentlyUnavailable = permanentlyUnavailable; } public InstanceHandle<? extends Servlet> getServlet() throws ServletException { if(servletContext.getDeployment().getDeploymentState() != DeploymentManager.State.STARTED) { throw UndertowServletMessages.MESSAGES.deploymentStopped(servletContext.getDeployment().getDeploymentInfo().getDeploymentName()); } if (!started) { synchronized (this) { if (!started) { instanceStrategy.start(); started = true; } } } return instanceStrategy.getServlet(); } public void forceInit() throws ServletException { if (!started) { if(servletContext.getDeployment().getDeploymentState() != DeploymentManager.State.STARTED) { throw UndertowServletMessages.MESSAGES.deploymentStopped(servletContext.getDeployment().getDeploymentInfo().getDeploymentName()); } synchronized (this) { if (!started) { try { instanceStrategy.start(); } catch (UnavailableException e) { handleUnavailableException(e); } started = true; } } } } public void handleUnavailableException(UnavailableException e) { if (e.isPermanent()) { UndertowServletLogger.REQUEST_LOGGER.stoppingServletDueToPermanentUnavailability(getServletInfo().getName(), e); stop(); setPermanentlyUnavailable(true); } else { long until = System.currentTimeMillis() + e.getUnavailableSeconds() * 1000; unavailableUntilUpdater.set(this, until); UndertowServletLogger.REQUEST_LOGGER.stoppingServletUntilDueToTemporaryUnavailability(getServletInfo().getName(), new Date(until), e); } } public ServletInfo getServletInfo() { return servletInfo; } public long getMaxRequestSize() { return maxRequestSize; } public FormParserFactory getFormParserFactory() { return formParserFactory; } public MultipartConfigElement getMultipartConfig() { return multipartConfig; } @Override public String toString() { return "ManagedServlet{" + "servletInfo=" + servletInfo + '}'; }
interface used to abstract the difference between single thread model servlets and normal servlets
/** * interface used to abstract the difference between single thread model servlets and normal servlets */
interface InstanceStrategy { void start() throws ServletException; void stop(); InstanceHandle<? extends Servlet> getServlet() throws ServletException; }
The default servlet pooling strategy that just uses a single instance for all requests
/** * The default servlet pooling strategy that just uses a single instance for all requests */
private static class DefaultInstanceStrategy implements InstanceStrategy { private final InstanceFactory<? extends Servlet> factory; private final ServletInfo servletInfo; private final ServletContextImpl servletContext; private volatile InstanceHandle<? extends Servlet> handle; private volatile Servlet instance; private ResourceChangeListener changeListener; private final InstanceHandle<Servlet> instanceHandle = new InstanceHandle<Servlet>() { @Override public Servlet getInstance() { return instance; } @Override public void release() { } }; DefaultInstanceStrategy(final InstanceFactory<? extends Servlet> factory, final ServletInfo servletInfo, final ServletContextImpl servletContext) { this.factory = factory; this.servletInfo = servletInfo; this.servletContext = servletContext; } public synchronized void start() throws ServletException { try { handle = factory.createInstance(); } catch (Exception e) { throw UndertowServletMessages.MESSAGES.couldNotInstantiateComponent(servletInfo.getName(), e); } instance = handle.getInstance(); new LifecyleInterceptorInvocation(servletContext.getDeployment().getDeploymentInfo().getLifecycleInterceptors(), servletInfo, instance, new ServletConfigImpl(servletInfo, servletContext)).proceed(); //if a servlet implements FileChangeCallback it will be notified of file change events final ResourceManager resourceManager = servletContext.getDeployment().getDeploymentInfo().getResourceManager(); if(instance instanceof ResourceChangeListener && resourceManager.isResourceChangeListenerSupported()) { resourceManager.registerResourceChangeListener(changeListener = (ResourceChangeListener) instance); } } public synchronized void stop() { if (handle != null) { final ResourceManager resourceManager = servletContext.getDeployment().getDeploymentInfo().getResourceManager(); if(changeListener != null) { resourceManager.removeResourceChangeListener(changeListener); } invokeDestroy(); handle.release(); } } private void invokeDestroy() { List<LifecycleInterceptor> interceptors = servletContext.getDeployment().getDeploymentInfo().getLifecycleInterceptors(); try { new LifecyleInterceptorInvocation(interceptors, servletInfo, instance).proceed(); } catch (Exception e) { UndertowServletLogger.ROOT_LOGGER.failedToDestroy(servletInfo, e); } } public InstanceHandle<? extends Servlet> getServlet() { return instanceHandle; } }
pooling strategy for single thread model servlet
/** * pooling strategy for single thread model servlet */
private static class SingleThreadModelPoolStrategy implements InstanceStrategy { private final InstanceFactory<? extends Servlet> factory; private final ServletInfo servletInfo; private final ServletContextImpl servletContext; private SingleThreadModelPoolStrategy(final InstanceFactory<? extends Servlet> factory, final ServletInfo servletInfo, final ServletContextImpl servletContext) { this.factory = factory; this.servletInfo = servletInfo; this.servletContext = servletContext; } @Override public void start() throws ServletException { if(servletInfo.getLoadOnStartup() != null) { //see UNDERTOW-734, make sure init method is called for load on startup getServlet().release(); } } @Override public void stop() { } @Override public InstanceHandle<? extends Servlet> getServlet() throws ServletException { final InstanceHandle<? extends Servlet> instanceHandle; final Servlet instance; //TODO: pooling try { instanceHandle = factory.createInstance(); } catch (Exception e) { throw UndertowServletMessages.MESSAGES.couldNotInstantiateComponent(servletInfo.getName(), e); } instance = instanceHandle.getInstance(); new LifecyleInterceptorInvocation(servletContext.getDeployment().getDeploymentInfo().getLifecycleInterceptors(), servletInfo, instance, new ServletConfigImpl(servletInfo, servletContext)).proceed(); return new InstanceHandle<Servlet>() { @Override public Servlet getInstance() { return instance; } @Override public void release() { try { instance.destroy(); } catch (Throwable t) { UndertowServletLogger.REQUEST_LOGGER.failedToDestroy(instance, t); } instanceHandle.release(); } }; } } }