Java tutorial
/* * RHQ Management Platform * Copyright (C) 2005-2008 Red Hat, Inc. * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ package org.rhq.enterprise.server.core; import java.io.InputStream; import java.util.ArrayList; import java.util.Collection; import java.util.Date; import java.util.HashMap; import java.util.Map; import java.util.regex.Matcher; import javax.annotation.Resource; import javax.ejb.Stateless; import javax.ejb.TransactionAttribute; import javax.ejb.TransactionAttributeType; import javax.mail.MessagingException; import javax.mail.Session; import javax.mail.Transport; import javax.mail.internet.InternetAddress; import javax.mail.internet.MimeMessage; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.rhq.core.util.stream.StreamUtil; import org.rhq.enterprise.server.RHQConstants; /** * EJB interface to an SMTP email system. * * @author John Mazzitelli */ @Stateless public class EmailManagerBean implements EmailManagerLocal { private static final Log LOG = LogFactory.getLog(EmailManagerBean.class); /** * The token string found in the email template file that will be replaced with a resource name. */ private static final String TEMPLATE_TOKEN_RESOURCE_NAME = "@@@RESOURCE_NAME@@@"; /** * The token string found in the email template file that will be replaced with an ascii tree structure containing * the names of resources up to the corresponding platform */ private static final String TEMPLATE_TOKEN_RESOURCE_HIERARCHY = "@@@FULL_RESOURCE_HIERARCHY@@@"; /** * The token string found in the email template file that will be replaced with an alert name. */ private static final String TEMPLATE_TOKEN_ALERT_NAME = "@@@ALERT_NAME@@@"; /** * The token string found in the email template file that will be replaced with a priority string. */ private static final String TEMPLATE_TOKEN_PRIORITY = "@@@PRIORITY@@@"; /** * The token string found in the email template file that will be replaced with a timestamp. */ private static final String TEMPLATE_TOKEN_TIMESTAMP = "@@@TIMESTAMP@@@"; /** * The token string found in the email template file that will be replaced with a condition set string. */ private static final String TEMPLATE_TOKEN_CONDITIONS = "@@@CONDITIONS@@@"; /** * The token string found in the email template file that will be replaced with a URL to a specific alert. */ private static final String TEMPLATE_TOKEN_ALERT_URL = "@@@ALERT_URL@@@"; @Resource(mappedName = "java:/Mail") private Session mailSession; /** * Send email to the addressses passed in toAddresses with the passed subject and body. Invalid emails will * be reported back. This can only catch sender errors up to the first smtp gateway. * @param toAddresses list of email addresses to send to * @param messageSubject subject of the email sent * @param messageBody body of the email to be sent * * @return list of email receivers for which initial delivery failed. */ public Collection<String> sendEmail(Collection<String> toAddresses, String messageSubject, String messageBody) { MimeMessage mimeMessage = new MimeMessage(mailSession); try { mimeMessage.setSubject(messageSubject); mimeMessage.setContent(messageBody, "text/plain"); } catch (MessagingException e) { e.printStackTrace(); // TODO: Customise this generated block return toAddresses; } Exception error = null; Collection<String> badAdresses = new ArrayList<String>(toAddresses.size()); // Send to each recipient individually, do not throw exceptions until we try them all for (String toAddress : toAddresses) { try { LOG.debug("Sending email [" + messageSubject + "] to recipient [" + toAddress + "]"); InternetAddress recipient = new InternetAddress(toAddress); Transport.send(mimeMessage, new InternetAddress[] { recipient }); } catch (Exception e) { LOG.error("Failed to send email [" + messageSubject + "] to recipient [" + toAddress + "]: " + e.getMessage()); badAdresses.add(toAddress); // Remember the first error - in case its due to a session initialization problem, // we don't want to lose the first error. if (error == null) { error = e; } } } if (error != null) { LOG.error("Sending of emails failed for this reason: " + error.getMessage()); } return badAdresses; } @TransactionAttribute(TransactionAttributeType.SUPPORTS) public Map<String, String> getAlertEmailMessage(String resourceHierarchy, String resourceName, String alertName, String priority, String timestamp, String conditionLogs, String alertUrl) { InputStream templateStream = this.getClass().getClassLoader() .getResourceAsStream("alert-email-template.txt"); String template = new String(StreamUtil.slurp(templateStream)); // the resource hierarchy could have backslash characters from new lines and/or resource names template = template.replaceAll(TEMPLATE_TOKEN_RESOURCE_HIERARCHY, cleanse(resourceHierarchy, "?Unknown Resource Hierarchy?")); // resource names will have backslashes in them when they represent some windows file system service template = template.replaceAll(TEMPLATE_TOKEN_RESOURCE_NAME, cleanse(resourceName, "?Unknown Resource?")); // nothing preventing a user from creating an alert definition named "my\cool?definition" template = template.replaceAll(TEMPLATE_TOKEN_ALERT_NAME, cleanse(alertName, "?Unknown Alert?")); //if the priority enum for alerts changes in the future, we'll be safe template = template.replaceAll(TEMPLATE_TOKEN_PRIORITY, cleanse(priority, "Medium")); // better to be paranoid and on the safe side than risk it just to save one line of code template = template.replaceAll(TEMPLATE_TOKEN_TIMESTAMP, cleanse(timestamp, new Date().toString())); // if replacements lookup from the message bundle fails, these will look like "?some.dot.delimited.property?" template = template.replaceAll(TEMPLATE_TOKEN_CONDITIONS, cleanse(conditionLogs, "?Unknown Condition Logs?")); // better to be paranoid and on the safe side than risk it just to save one line of code template = template.replaceAll(TEMPLATE_TOKEN_ALERT_URL, cleanse(alertUrl, "?Unknown URL?")); String subject = "[" + RHQConstants.PRODUCT_NAME + "] Alert"; if (template.startsWith("Subject:")) { try { subject = template.substring("Subject:".length(), template.indexOf('\n')); } catch (RuntimeException ignore) { LOG.warn("Bad alert template file - can't determine the subject, using a default"); } } Map<String, String> message = new HashMap<String, String>(1); message.put(subject, template); return message; } /* * if we don't escape the regex special characters '\' and '$', they will be interpreted differently * than desired; quoteReplacement was specifically written to help alleviate this common scenario: * * http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6523151 */ private String cleanse(String passedValue, String defaultValue) { String results = passedValue; if (results == null) { results = defaultValue; } // cleanse no matter what, because it's possible the defaultValue has invalid characters too return Matcher.quoteReplacement(results); } }