Java tutorial
/* * Copyright 2012-2017 the original author or authors. * * 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 org.springframework.boot.web.embedded.tomcat; import java.util.Set; import javax.servlet.ServletContainerInitializer; import javax.servlet.ServletContext; import javax.servlet.ServletException; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.boot.web.servlet.ServletContextInitializer; /** * {@link ServletContainerInitializer} used to trigger {@link ServletContextInitializer * ServletContextInitializers} and track startup errors. * * @author Phillip Webb * @author Andy Wilkinson */ class TomcatStarter implements ServletContainerInitializer { private static final Log logger = LogFactory.getLog(TomcatStarter.class); private final ServletContextInitializer[] initializers; private volatile Exception startUpException; TomcatStarter(ServletContextInitializer[] initializers) { this.initializers = initializers; } @Override public void onStartup(Set<Class<?>> classes, ServletContext servletContext) throws ServletException { try { for (ServletContextInitializer initializer : this.initializers) { initializer.onStartup(servletContext); } } catch (Exception ex) { this.startUpException = ex; // Prevent Tomcat from logging and re-throwing when we know we can // deal with it in the main thread, but log for information here. if (logger.isErrorEnabled()) { logger.error("Error starting Tomcat context. Exception: " + ex.getClass().getName() + ". Message: " + ex.getMessage()); } } } public Exception getStartUpException() { return this.startUpException; } }