Java tutorial
/*! * This program is free software; you can redistribute it and/or modify it under the * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software * Foundation. * * You should have received a copy of the GNU Lesser General Public License along with this * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html * or from the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * * 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 Lesser General Public License for more details. * * Copyright (c) 2002-2017 Hitachi Vantara.. All rights reserved. */ package org.pentaho.reporting.libraries.base.boot; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * The package state class is used by the package manager to keep track of the activation level of the installed or * errornous packages. * <p/> * This is an internal class used by the PackageManager. * * @author Thomas Morgner */ public class PackageState { /** * A logger. */ private static final Log LOGGER = LogFactory.getLog(PackageState.class); /** * A constant defining that the package is new. */ public static final int STATE_NEW = 0; /** * A constant defining that the package has been loaded and configured. */ public static final int STATE_CONFIGURED = 1; /** * A constant defining that the package was initialized and is ready to use. */ public static final int STATE_INITIALIZED = 2; /** * A constant defining that the package produced an error and is not available. */ public static final int STATE_ERROR = -2; /** * The module class that contains the package information. */ private final Module module; /** * The state of the module. */ private int state; /** * Creates a new package state for the given module. The module state will be initialized to STATE_NEW. * * @param module the module. */ public PackageState(final Module module) { this(module, STATE_NEW); } /** * Creates a new package state for the given module. The module state will be initialized to the given initial state. * * @param module the module. * @param state the initial state */ public PackageState(final Module module, final int state) { if (module == null) { throw new NullPointerException("Module must not be null."); } if (state != STATE_CONFIGURED && state != STATE_ERROR && state != STATE_INITIALIZED && state != STATE_NEW) { throw new IllegalArgumentException("State is not valid"); } this.module = module; this.state = state; } /** * Configures the module and raises the state to STATE_CONFIGURED if the module is not yet configured. * * @param subSystem the sub-system. * @return true, if the module was configured, false otherwise. */ public boolean configure(final SubSystem subSystem) { if (subSystem == null) { throw new NullPointerException(); } if (this.state == STATE_NEW) { try { this.module.configure(subSystem); this.state = STATE_CONFIGURED; return true; } catch (NoClassDefFoundError noClassDef) { LOGGER.warn("Unable to load module classes for " + this.module.getName() + ':' + noClassDef.getMessage()); this.state = STATE_ERROR; } catch (Exception e) { if (LOGGER.isDebugEnabled()) { // its still worth a warning, but now we are more verbose ... LOGGER.warn("Unable to configure the module " + this.module.getName(), e); } else if (LOGGER.isWarnEnabled()) { LOGGER.warn("Unable to configure the module " + this.module.getName()); } this.state = STATE_ERROR; } } return false; } /** * Returns the module managed by this state implementation. * * @return the module. */ public Module getModule() { return this.module; } /** * Returns the current state of the module. This method returns either STATE_NEW, STATE_CONFIGURED, STATE_INITIALIZED * or STATE_ERROR. * * @return the module state. */ public int getState() { return this.state; } /** * Initializes the contained module and raises the set of the module to STATE_INITIALIZED, if the module was not yet * initialized. In case of an error, the module state will be set to STATE_ERROR and the module will not be * available. * * @param subSystem the sub-system. * @return true, if the module was successfully initialized, false otherwise. */ public boolean initialize(final SubSystem subSystem) { if (subSystem == null) { throw new NullPointerException(); } if (this.state == STATE_CONFIGURED) { try { this.module.initialize(subSystem); this.state = STATE_INITIALIZED; return true; } catch (NoClassDefFoundError noClassDef) { LOGGER.warn("Unable to load module classes for " + this.module.getName() + ':' + noClassDef.getMessage()); this.state = STATE_ERROR; } catch (ModuleInitializeException me) { if (LOGGER.isDebugEnabled()) { // its still worth a warning, but now we are more verbose ... LOGGER.warn("Unable to initialize the module " + this.module.getName(), me); } else if (LOGGER.isWarnEnabled()) { LOGGER.warn("Unable to initialize the module " + this.module.getName()); } this.state = STATE_ERROR; } catch (Exception e) { if (LOGGER.isDebugEnabled()) { // its still worth a warning, but now we are more verbose ... LOGGER.warn("Unable to initialize the module " + this.module.getName(), e); } else if (LOGGER.isWarnEnabled()) { LOGGER.warn("Unable to initialize the module " + this.module.getName()); } this.state = STATE_ERROR; } } return false; } /** * Compares this object with the given other object for equality. * * @param o the other object to be compared * @return true, if the other object is also a PackageState containing the same module, false otherwise. * @see Object#equals(Object) */ public boolean equals(final Object o) { if (this == o) { return true; } if (!(o instanceof PackageState)) { return false; } final PackageState packageState = (PackageState) o; if (!this.module.getModuleClass().equals(packageState.module.getModuleClass())) { return false; } return true; } /** * Computes a hashcode for this package state. * * @return the hashcode. * @see Object#hashCode() */ public int hashCode() { return this.module.hashCode(); } /** * Marks this package state as invalid. */ public void markError() { this.state = STATE_ERROR; } }