All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.jfree.base.modules.PackageManager Maven / Gradle / Ivy

Go to download

jtstand-common is a library derived from jcommon, used by jtstand-chart, which is derived from jfreechart

There is a newer version: 1.5.9
Show newest version
/*
 * Copyright (c) 2009 Albert Kurucz. 
 *
 * This file, PackageManager.java is part of JTStand.
 *
 * JTStand is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * JTStand 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.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with GTStand.  If not, see .
 */

package org.jfree.base.modules;

import java.io.PrintStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;

import org.jfree.base.AbstractBoot;
import org.jfree.base.config.HierarchicalConfiguration;
import org.jfree.base.config.PropertyFileConfiguration;
import org.jfree.base.log.PadMessage;
import org.jfree.util.Configuration;
import org.jfree.util.Log;
import org.jfree.util.ObjectUtilities;

/**
 * The PackageManager is used to load and configure the modules of JFreeReport.
 * Modules are used to extend the basic capabilities of JFreeReport by providing
 * a simple plugin-interface.
 * 

* Modules provide a simple capability to remove unneeded functionality from the * JFreeReport system and to reduce the overall code size. The modularisation provides * a very strict way of removing unnecessary dependencies beween the various packages. *

* The package manager can be used to add new modules to the system or to check * the existence and state of installed modules. * * @author Thomas Morgner */ public final class PackageManager { /** * The PackageConfiguration handles the module level configuration. * * @author Thomas Morgner */ public static class PackageConfiguration extends PropertyFileConfiguration { /** * DefaultConstructor. Creates a new package configuration. */ public PackageConfiguration() { // nothing required } /** * The new configuartion will be inserted into the list of report configuration, * so that this configuration has the given report configuration instance as parent. * * @param config the new report configuration. */ public void insertConfiguration(final HierarchicalConfiguration config) { super.insertConfiguration(config); } } /** * An internal constant declaring that the specified module was already loaded. */ private static final int RETURN_MODULE_LOADED = 0; /** * An internal constant declaring that the specified module is not known. */ private static final int RETURN_MODULE_UNKNOWN = 1; /** * An internal constant declaring that the specified module produced an error while loading. */ private static final int RETURN_MODULE_ERROR = 2; /** * The module configuration instance that should be used to store module * properties. This separates the user defined properties from the implementation * defined properties. */ private final PackageConfiguration packageConfiguration; /** * A list of all defined modules. */ private final ArrayList modules; /** * A list of module name definitions. */ private final ArrayList initSections; /** The boot implementation for which the modules are managed. */ private AbstractBoot booter; /** The instances of all modules for all booters. */ private static HashMap instances; /** * Creates a package manager instance. * * @param booter the booter. * @return A package manager. */ public static PackageManager createInstance(final AbstractBoot booter) { PackageManager manager; if (instances == null) { instances = new HashMap(); manager = new PackageManager(booter); instances.put(booter, manager); return manager; } manager = (PackageManager) instances.get(booter); if (manager == null) { manager = new PackageManager(booter); instances.put(booter, manager); } return manager; } /** * Creates a new package manager. * * @param booter the booter (null not permitted). */ private PackageManager(final AbstractBoot booter) { if (booter == null) { throw new NullPointerException(); } this.booter = booter; this.packageConfiguration = new PackageConfiguration(); this.modules = new ArrayList(); this.initSections = new ArrayList(); } /** * Checks, whether a certain module is available. * * @param moduleDescription the module description of the desired module. * @return true, if the module is available and the version of the module * is compatible, false otherwise. */ public boolean isModuleAvailable(final ModuleInfo moduleDescription) { final PackageState[] packageStates = (PackageState[]) this.modules.toArray(new PackageState[this.modules.size()]); for (int i = 0; i < packageStates.length; i++) { final PackageState state = packageStates[i]; if (state.getModule().getModuleClass().equals(moduleDescription.getModuleClass())) { return (state.getState() == PackageState.STATE_INITIALIZED); } } return false; } /** * Loads all modules mentioned in the report configuration starting with * the given prefix. This method is used during the boot process of * JFreeReport. You should never need to call this method directly. * * @param modulePrefix the module prefix. */ public void load(final String modulePrefix) { if (this.initSections.contains(modulePrefix)) { return; } this.initSections.add(modulePrefix); final Configuration config = this.booter.getGlobalConfig(); final Iterator it = config.findPropertyKeys(modulePrefix); int count = 0; while (it.hasNext()) { final String key = (String) it.next(); if (key.endsWith(".Module")) { final String moduleClass = config.getConfigProperty(key); if (moduleClass != null && moduleClass.length() > 0) { addModule(moduleClass); count++; } } } Log.debug("Loaded a total of " + count + " modules under prefix: " + modulePrefix); } /** * Initializes all previously uninitialized modules. Once a module is initialized, * it is not re-initialized a second time. */ public synchronized void initializeModules() { // sort by subsystems and dependency PackageSorter.sort(this.modules); for (int i = 0; i < this.modules.size(); i++) { final PackageState mod = (PackageState) this.modules.get(i); if (mod.configure(this.booter)) { Log.debug(new Log.SimpleMessage("Conf: ", new PadMessage(mod.getModule().getModuleClass(), 70), " [", mod.getModule().getSubSystem(), "]")); } } for (int i = 0; i < this.modules.size(); i++) { final PackageState mod = (PackageState) this.modules.get(i); if (mod.initialize(this.booter)) { Log.debug(new Log.SimpleMessage("Init: ", new PadMessage(mod.getModule().getModuleClass(), 70), " [", mod.getModule().getSubSystem(), "]")); } } } /** * Adds a module to the package manager. * Once all modules are added, you have to call initializeModules() * to configure and initialize the new modules. * * @param modClass the module class */ public synchronized void addModule(final String modClass) { final ArrayList loadModules = new ArrayList(); final ModuleInfo modInfo = new DefaultModuleInfo (modClass, null, null, null); if (loadModule(modInfo, new ArrayList(), loadModules, false)) { for (int i = 0; i < loadModules.size(); i++) { final Module mod = (Module) loadModules.get(i); this.modules.add(new PackageState(mod)); } } } /** * Checks, whether the given module is already loaded in either the given * tempModules list or the global package registry. If tmpModules is null, * only the previously installed modules are checked. * * @param tempModules a list of previously loaded modules. * @param module the module specification that is checked. * @return true, if the module is already loaded, false otherwise. */ private int containsModule(final ArrayList tempModules, final ModuleInfo module) { if (tempModules != null) { final ModuleInfo[] mods = (ModuleInfo[]) tempModules.toArray(new ModuleInfo[tempModules.size()]); for (int i = 0; i < mods.length; i++) { if (mods[i].getModuleClass().equals(module.getModuleClass())) { return RETURN_MODULE_LOADED; } } } final PackageState[] packageStates = (PackageState[]) this.modules.toArray(new PackageState[this.modules.size()]); for (int i = 0; i < packageStates.length; i++) { if (packageStates[i].getModule().getModuleClass().equals(module.getModuleClass())) { if (packageStates[i].getState() == PackageState.STATE_ERROR) { return RETURN_MODULE_ERROR; } else { return RETURN_MODULE_LOADED; } } } return RETURN_MODULE_UNKNOWN; } /** * A utility method that collects all failed modules. Such an module caused * an error while being loaded, and is now cached in case it is referenced * elsewhere. * * @param state the failed module. */ private void dropFailedModule(final PackageState state) { if (this.modules.contains(state) == false) { this.modules.add(state); } } /** * Tries to load a given module and all dependent modules. If the dependency check * fails for that module (or for one of the dependent modules), the loaded modules * are discarded and no action is taken. * * @param moduleInfo the module info of the module that should be loaded. * @param incompleteModules a list of incompletly loaded modules. This are module * specifications which depend on the current module and wait for the module to * be completly loaded. * @param modules the list of previously loaded modules for this module. * @param fatal a flag that states, whether the failure of loading a module should * be considered an error. Root-modules load errors are never fatal, as we try * to load all known modules, regardless whether they are active or not. * @return true, if the module was loaded successfully, false otherwise. */ private boolean loadModule(final ModuleInfo moduleInfo, final ArrayList incompleteModules, final ArrayList modules, final boolean fatal) { try { final Class c = ObjectUtilities.getClassLoader(getClass()).loadClass(moduleInfo.getModuleClass()); final Module module = (Module) c.newInstance(); if (acceptVersion(moduleInfo, module) == false) { // module conflict! Log.warn("Module " + module.getName() + ": required version: " + moduleInfo + ", but found Version: \n" + module); final PackageState state = new PackageState(module, PackageState.STATE_ERROR); dropFailedModule(state); return false; } final int moduleContained = containsModule(modules, module); if (moduleContained == RETURN_MODULE_ERROR) { // the module caused harm before ... Log.debug("Indicated failure for module: " + module.getModuleClass()); final PackageState state = new PackageState(module, PackageState.STATE_ERROR); dropFailedModule(state); return false; } else if (moduleContained == RETURN_MODULE_UNKNOWN) { if (incompleteModules.contains(module)) { // we assume that loading will continue ... Log.error(new Log.SimpleMessage ("Circular module reference: This module definition is invalid: ", module.getClass())); final PackageState state = new PackageState(module, PackageState.STATE_ERROR); dropFailedModule(state); return false; } incompleteModules.add(module); final ModuleInfo[] required = module.getRequiredModules(); for (int i = 0; i < required.length; i++) { if (loadModule(required[i], incompleteModules, modules, true) == false) { Log.debug("Indicated failure for module: " + module.getModuleClass()); final PackageState state = new PackageState(module, PackageState.STATE_ERROR); dropFailedModule(state); return false; } } final ModuleInfo[] optional = module.getOptionalModules(); for (int i = 0; i < optional.length; i++) { if (loadModule(optional[i], incompleteModules, modules, true) == false) { Log.debug(new Log.SimpleMessage("Optional module: ", optional[i].getModuleClass(), " was not loaded.")); } } // maybe a dependent module defined the same base module ... if (containsModule(modules, module) == RETURN_MODULE_UNKNOWN) { modules.add(module); } incompleteModules.remove(module); } return true; } catch (ClassNotFoundException cnfe) { if (fatal) { Log.warn(new Log.SimpleMessage ("Unresolved dependency for package: ", moduleInfo.getModuleClass())); } Log.debug(new Log.SimpleMessage("ClassNotFound: ", cnfe.getMessage())); return false; } catch (Exception e) { Log.warn(new Log.SimpleMessage("Exception while loading module: ", moduleInfo), e); return false; } } /** * Checks, whether the given module meets the requirements defined in the module * information. * * @param moduleRequirement the required module specification. * @param module the module that should be checked against the specification. * @return true, if the module meets the given specifications, false otherwise. */ private boolean acceptVersion(final ModuleInfo moduleRequirement, final Module module) { if (moduleRequirement.getMajorVersion() == null) { return true; } if (module.getMajorVersion() == null) { Log.warn("Module " + module.getName() + " does not define a major version."); } else { final int compare = acceptVersion(moduleRequirement.getMajorVersion(), module.getMajorVersion()); if (compare > 0) { return false; } else if (compare < 0) { return true; } } if (moduleRequirement.getMinorVersion() == null) { return true; } if (module.getMinorVersion() == null) { Log.warn("Module " + module.getName() + " does not define a minor version."); } else { final int compare = acceptVersion(moduleRequirement.getMinorVersion(), module.getMinorVersion()); if (compare > 0) { return false; } else if (compare < 0) { return true; } } if (moduleRequirement.getPatchLevel() == null) { return true; } if (module.getPatchLevel() == null) { Log.debug("Module " + module.getName() + " does not define a patch level."); } else { if (acceptVersion(moduleRequirement.getPatchLevel(), module.getPatchLevel()) > 0) { Log.debug("Did not accept patchlevel: " + moduleRequirement.getPatchLevel() + " - " + module.getPatchLevel()); return false; } } return true; } /** * Compare the version strings. If the strings have a different length, * the shorter string is padded with spaces to make them compareable. * * @param modVer the version string of the module * @param depModVer the version string of the dependent or optional module * @return 0, if the dependent module version is equal tothe module's required * version, a negative number if the dependent module is newer or a positive * number if the dependent module is older and does not fit. */ private int acceptVersion(final String modVer, final String depModVer) { final int mLength = Math.max(modVer.length(), depModVer.length()); final char[] modVerArray; final char[] depVerArray; if (modVer.length() > depModVer.length()) { modVerArray = modVer.toCharArray(); depVerArray = new char[mLength]; final int delta = modVer.length() - depModVer.length(); Arrays.fill(depVerArray, 0, delta, ' '); System.arraycopy(depVerArray, delta, depModVer.toCharArray(), 0, depModVer.length()); } else if (modVer.length() < depModVer.length()) { depVerArray = depModVer.toCharArray(); modVerArray = new char[mLength]; final char[] b1 = new char[mLength]; final int delta = depModVer.length() - modVer.length(); Arrays.fill(b1, 0, delta, ' '); System.arraycopy(b1, delta, modVer.toCharArray(), 0, modVer.length()); } else { depVerArray = depModVer.toCharArray(); modVerArray = modVer.toCharArray(); } return new String(modVerArray).compareTo(new String(depVerArray)); } /** * Returns the default package configuration. Private report configuration * instances may be inserted here. These inserted configuration can never override * the settings from this package configuration. * * @return the package configuration. */ public PackageConfiguration getPackageConfiguration() { return this.packageConfiguration; } /** * Returns an array of the currently active modules. The module definition * returned contain all known modules, including buggy and unconfigured * instances. * * @return the modules. */ public Module[] getAllModules() { final Module[] mods = new Module[this.modules.size()]; for (int i = 0; i < this.modules.size(); i++) { final PackageState state = (PackageState) this.modules.get(i); mods[i] = state.getModule(); } return mods; } /** * Returns all active modules. This array does only contain modules * which were successfully configured and initialized. * * @return the list of all active modules. */ public Module[] getActiveModules() { final ArrayList mods = new ArrayList(); for (int i = 0; i < this.modules.size(); i++) { final PackageState state = (PackageState) this.modules.get(i); if (state.getState() == PackageState.STATE_INITIALIZED) { mods.add(state.getModule()); } } return (Module[]) mods.toArray(new Module[mods.size()]); } /** * Prints the modules that are used. * * @param p the print stream. */ public void printUsedModules(final PrintStream p) { final Module[] allMods = getAllModules(); final ArrayList activeModules = new ArrayList(); final ArrayList failedModules = new ArrayList(); for (int i = 0; i < allMods.length; i++) { if (isModuleAvailable(allMods[i])) { activeModules.add(allMods[i]); } else { failedModules.add(allMods[i]); } } p.print("Active modules: "); p.println(activeModules.size()); p.println("----------------------------------------------------------"); for (int i = 0; i < activeModules.size(); i++) { final Module mod = (Module) activeModules.get(i); p.print(new PadMessage(mod.getModuleClass(), 70)); p.print(" ["); p.print(mod.getSubSystem()); p.println("]"); p.print(" Version: "); p.print(mod.getMajorVersion()); p.print("-"); p.print(mod.getMinorVersion()); p.print("-"); p.print(mod.getPatchLevel()); p.print(" Producer: "); p.println(mod.getProducer()); p.print(" Description: "); p.println(mod.getDescription()); } } }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy