AuditorFactory.java

/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 2006-2011, QOS.ch. All rights reserved.
 * 
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *  
 *   or (per the licensee's choosing)
 *  
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */

package ch.qos.logback.audit.client;

import java.net.InetAddress;
import java.net.URL;
import java.net.UnknownHostException;

import ch.qos.logback.audit.Application;
import ch.qos.logback.audit.AuditException;
import ch.qos.logback.audit.client.joran.JoranConfigurator;
import ch.qos.logback.core.joran.spi.JoranException;
import ch.qos.logback.core.status.Status;
import ch.qos.logback.core.status.StatusChecker;
import ch.qos.logback.core.status.StatusManager;
import ch.qos.logback.core.util.Loader;
import ch.qos.logback.core.util.OptionHelper;
import ch.qos.logback.core.util.StatusPrinter;

public class AuditorFactory {

  static final String DEFAULT_AUDITOR_NAME = "default";
  static final String AUTOCONFIG_FILE = "logback-audit.xml";
  static final String TEST_AUTOCONFIG_FILE = "logback-audit-test.xml";

  static final public String AUTOCONFIG_FILE_PROPERTY = "logback.audit.autoconfig.file";

  static final public String NULL_CLIENT_APPLICATON_URL = "http://audit.qos.ch/codes.html#nullClientApp";
  static final public String NULL_AUDIT_APPENDER_URL = "http://audit.qos.ch/codes.html#nullAuditAppender";

  static Auditor defaultAuditor;

  static Application clientApplication;

  static void checkSanity(Auditor auditor) throws AuditException {
    StatusManager sm = auditor.getStatusManager();
    StatusChecker checker = new StatusChecker(sm);
    if (checker.getHighestLevel(0) > Status.INFO) {
      StatusPrinter.print(sm);
    }
    
    if (auditor.getClientApplication() == null) {
      throw new AuditException("Client application has not been set");
    }
    
    if (auditor.getAuditAppender() == null) {
      throw new AuditException("No audit appender. Please see "
          + NULL_AUDIT_APPENDER_URL);
    }
  }

  public static void setApplicationName(String name) throws AuditException {
    if(clientApplication != null && clientApplication.getName().equals(name)) {
      // don't configure again
      return;
    }
    if (clientApplication != null && !clientApplication.getName().equals(name)) {
      throw new IllegalStateException("Application name "
          + clientApplication.getName() + " once set cannot be renamed.");
    }

    if (OptionHelper.isEmpty(name)) {
      throw new IllegalArgumentException(
          "Application name cannot be null or empty");
    } else {

      // logger.info("Naming client application as [" + name + "]");
    }

    try {
      InetAddress address = InetAddress.getLocalHost();
      String fqdn = address.getCanonicalHostName();
      // logger("Client application host is ["+fqdn+"].");
      Application aplication = new Application(name, fqdn);
      // all is nice and dandy
      clientApplication = aplication;
    } catch (UnknownHostException e) {
      throw new IllegalStateException(
          "Failed to determine the hostname for this host", e);
    }

    // defaultAuditor.close();
    defaultAuditor = new Auditor();
    defaultAuditor.setClientApplication(clientApplication);
    defaultAuditor.setName(DEFAULT_AUDITOR_NAME);
    autoConfig(defaultAuditor);
    checkSanity(defaultAuditor);
  }

  /**
   * Get the default auditor. If it has not been previously configured, this
   * method will also configure the default auditor. In case of problems, this
   * method may throw an exception.
   * 
   * @return
   * @throws AuditException
   */
  public static Auditor getAuditor() {
    return defaultAuditor;
  }

  public static void autoConfig(Auditor auditor) throws AuditException {
    ClassLoader tccl = Loader.getTCL();
    autoConfig(auditor, tccl);
  }

  public static void configureByResource(Auditor auditor, URL url)
      throws AuditException {
    if (url == null) {
      throw new IllegalArgumentException("URL argument cannot be null");
    }
    JoranConfigurator configurator = new JoranConfigurator();
    configurator.setContext(auditor);

    try {
      configurator.doConfigure(url);
    } catch (JoranException e) {
      throw new AuditException("Configuration failure in " + url, e);
    }

  }

  public static void autoConfig(Auditor auditor, ClassLoader classLoader)
      throws AuditException {

    String autoConfigFileByProperty = System
        .getProperty(AUTOCONFIG_FILE_PROPERTY);
    String pathPrefix = clientApplication.getName() + "/";
    URL url = null;

    if (autoConfigFileByProperty != null) {
      url = Loader.getResource(pathPrefix + autoConfigFileByProperty,
          classLoader);

    } else {
      url = Loader.getResource(pathPrefix + TEST_AUTOCONFIG_FILE, classLoader);
      if (url == null) {
        url = Loader.getResource(pathPrefix + AUTOCONFIG_FILE, classLoader);
      }
    }
    if (url != null) {
      configureByResource(auditor, url);
    } else {
      String errMsg;
      if (autoConfigFileByProperty != null) {
        errMsg = "Failed to find configuration file [" + pathPrefix
            + autoConfigFileByProperty + "].";
      } else {
        errMsg = "Failed to find logback-audit configuration files  ["
            + pathPrefix + TEST_AUTOCONFIG_FILE + "] or [" + pathPrefix
            + AUTOCONFIG_FILE + "].";
      }
      throw new AuditException(errMsg);
    }
  }

  static public void reset() {
    clientApplication = null;
    if (defaultAuditor != null) {
      defaultAuditor.shutdown();
    }
    defaultAuditor = null;
  }

}