Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.apache.isis.core.commons.configbuilder; import java.io.IOException; import java.util.Arrays; import java.util.List; import java.util.Properties; import java.util.Set; import org.apache.commons.cli.BasicParser; import org.apache.commons.cli.CommandLine; import org.apache.commons.cli.CommandLineParser; import org.apache.commons.cli.Options; import org.apache.commons.cli.ParseException; import org.apache.isis.core.commons.config.ConfigurationConstants; import org.apache.isis.core.commons.config.IsisConfiguration; import org.apache.isis.core.commons.config.IsisConfigurationDefault; import org.apache.isis.core.commons.config.IsisConfigurationDefault.ContainsPolicy; import org.apache.isis.core.commons.config.NotFoundPolicy; import org.apache.isis.core.commons.exceptions.IsisException; import org.apache.isis.core.commons.resource.ResourceStreamSource; import org.apache.isis.core.commons.resource.ResourceStreamSourceChainOfResponsibility; import org.apache.isis.core.commons.resource.ResourceStreamSourceFileSystem; import org.apache.isis.core.runtime.optionhandler.BootPrinter; import org.apache.isis.core.runtime.optionhandler.OptionHandler; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.common.base.Objects; import com.google.common.collect.Sets; /** * Holds a mutable set of properties representing the configuration. * * This implementation loads the specified * configuration resource (file) from the given {@link ResourceStreamSource}(s). * * <p> * If a property is in multiple configuration resources then the latter * resources will overwrite the former. * * <p> * Mutable/immutable pair with the {@link IsisConfiguration}. To obtain the * configuration, use {@link #getConfiguration()}. * * @see {@link IsisConfiguration} for more details on the mutable/immutable pair pattern. * */ public final class IsisConfigurationBuilder { private static final Logger LOG = LoggerFactory.getLogger(IsisConfigurationBuilder.class); //region > constructor, fields private final ResourceStreamSourceChainOfResponsibility resourceStreamSourceChain; /* package */ final IsisConfigurationDefault configuration; private boolean locked; private final Set<String> configurationResourcesFound = Sets.newLinkedHashSet(); private final Set<String> configurationResourcesNotFound = Sets.newLinkedHashSet(); public IsisConfigurationBuilder() { this(ResourceStreamSourceFileSystem.create(ConfigurationConstants.DEFAULT_CONFIG_DIRECTORY)); } public IsisConfigurationBuilder(final ResourceStreamSource... resourceStreamSources) { this(createComposite(Arrays.asList(resourceStreamSources))); } public IsisConfigurationBuilder(final List<ResourceStreamSource> resourceStreamSources) { this(createComposite(resourceStreamSources)); } public IsisConfigurationBuilder(final ResourceStreamSourceChainOfResponsibility resourceStreamSourceChain) { this.resourceStreamSourceChain = resourceStreamSourceChain; configuration = new IsisConfigurationDefault(resourceStreamSourceChain); } private static ResourceStreamSourceChainOfResponsibility createComposite( final List<ResourceStreamSource> resourceStreamSources) { final ResourceStreamSourceChainOfResponsibility composite = new ResourceStreamSourceChainOfResponsibility(); for (final ResourceStreamSource rss : resourceStreamSources) { if (rss == null) { continue; } composite.addResourceStreamSource(rss); } return composite; } public void addDefaultConfigurationResourcesAndPrimers() { addDefaultConfigurationResources(); addDefaultPrimers(); } private void addDefaultConfigurationResources() { IsisConfigurationDefault.ContainsPolicy ignorePolicy = IsisConfigurationDefault.ContainsPolicy.IGNORE; NotFoundPolicy continuePolicy = NotFoundPolicy.CONTINUE; addConfigurationResource(ConfigurationConstants.DEFAULT_CONFIG_FILE, NotFoundPolicy.FAIL_FAST, ignorePolicy); addConfigurationResource(ConfigurationConstants.WEB_CONFIG_FILE, continuePolicy, ignorePolicy); addConfigurationResource("war.properties", continuePolicy, ignorePolicy); addConfigurationResource("viewer_wicket.properties", continuePolicy, ignorePolicy); addConfigurationResource("viewer_restful.properties", continuePolicy, ignorePolicy); addConfigurationResource("viewer_restfulobjects.properties", continuePolicy, ignorePolicy); addConfigurationResource("persistor_datanucleus.properties", continuePolicy, ignorePolicy); addConfigurationResource("persistor.properties", continuePolicy, ignorePolicy); addConfigurationResource("authentication_shiro.properties", continuePolicy, ignorePolicy); addConfigurationResource("authentication_bypass.properties", continuePolicy, ignorePolicy); addConfigurationResource("authentication.properties", continuePolicy, ignorePolicy); addConfigurationResource("authorization_shiro.properties", continuePolicy, ignorePolicy); addConfigurationResource("authorization_bypass.properties", continuePolicy, ignorePolicy); addConfigurationResource("authorization.properties", continuePolicy, ignorePolicy); addConfigurationResource("reflector_java.properties", continuePolicy, ignorePolicy); addConfigurationResource("reflector.properties", continuePolicy, ignorePolicy); addConfigurationResource("fixtures-installer_configuration.properties", continuePolicy, ignorePolicy); addConfigurationResource("fixtures-installer.properties", continuePolicy, ignorePolicy); addConfigurationResource("services-installer_annotation.properties", continuePolicy, ignorePolicy); addConfigurationResource("services-installer_configuration.properties", continuePolicy, ignorePolicy); addConfigurationResource("services-installer_configuration-and-annotation.properties", continuePolicy, ignorePolicy); addConfigurationResource("services-installer.properties", continuePolicy, ignorePolicy); // both override and overrides are accepted (because I keep forgetting which) addConfigurationResource("override.properties", NotFoundPolicy.CONTINUE, IsisConfigurationDefault.ContainsPolicy.OVERWRITE); addConfigurationResource("overrides.properties", NotFoundPolicy.CONTINUE, IsisConfigurationDefault.ContainsPolicy.OVERWRITE); } private void addDefaultPrimers() { primeWith(new PrimerForSystemProperties()); primeWith(new PrimerForEnvironmentVariablesIsisPrefix()); primeWith(new PrimerForEnvironmentVariableISIS_OPT()); } //endregion //region > addResourceStreamSource, addResourceStreamSources public void addResourceStreamSource(final ResourceStreamSource resourceStreamSource) { addResourceStreamSources(resourceStreamSource); } public void addResourceStreamSources(final ResourceStreamSource... resourceStreamSources) { addResourceStreamSources(Arrays.asList(resourceStreamSources)); } public void addResourceStreamSources(final List<ResourceStreamSource> resourceStreamSources) { ensureNotLocked(); for (ResourceStreamSource resourceStreamSource : resourceStreamSources) { this.resourceStreamSourceChain.addResourceStreamSource(resourceStreamSource); } } //endregion //region > addConfigurationResource /** * Registers the configuration resource (usually, a file) with the specified * name from the first {@link ResourceStreamSource} available. * * <p> * If the configuration resource cannot be found then the provided * {@link NotFoundPolicy} determines whether an exception is thrown or not. * * <p> * Must be called before {@link IsisConfigurationBuilder#getConfiguration()}. */ public void addConfigurationResource(final String configurationResource, final NotFoundPolicy notFoundPolicy, final IsisConfigurationDefault.ContainsPolicy containsPolicy) { ensureNotLocked(); if (LOG.isDebugEnabled()) { LOG.debug(String.format("checking availability of configuration resource: %s, notFoundPolicy: %s", configurationResource, notFoundPolicy)); } loadConfigurationResource(configurationResource, notFoundPolicy, containsPolicy); } /** * Loads the configuration resource (usually, a file) with the specified * name from the first {@link ResourceStreamSource} available. * * <p> * If the configuration resource cannot be found then the provided * {@link NotFoundPolicy} determines whether an exception is thrown or not. */ private void loadConfigurationResource(final String configurationResource, final NotFoundPolicy notFoundPolicy, final IsisConfigurationDefault.ContainsPolicy containsPolicy) { try { final PropertiesReader propertiesReader = loadConfigurationResource(resourceStreamSourceChain, configurationResource); LOG.info("loading properties from " + configurationResource); configuration.add(propertiesReader.getProperties(), containsPolicy); configurationResourcesFound.add(configurationResource); return; } catch (final IOException ignore) { // ignore } if (notFoundPolicy == NotFoundPolicy.FAIL_FAST) { throw new IsisException(String.format("failed to load '%s'; tried using: %s", configurationResource, resourceStreamSourceChain.getName())); } configurationResourcesNotFound.add(configurationResource); if (LOG.isDebugEnabled()) { LOG.debug(String.format("'%s' not found, but not needed", configurationResource)); } } private PropertiesReader loadConfigurationResource(final ResourceStreamSource resourceStreamSource, final String configurationResource) throws IOException { return new PropertiesReader(resourceStreamSource, configurationResource); } //endregion //region > add, put /** * Adds additional property; if already present then will _not_ be replaced. */ public void add(final String key, final String value) { ensureNotLocked(); configuration.add(key, value); } /** * Adds/updates property; if already present then _will_ be replaced. */ public void put(final String key, final String value) { ensureNotLocked(); configuration.put(key, value); } //endregion //region > parseAndPrimeWith, primeWith public boolean parseAndPrimeWith(final List<OptionHandler> optionHandlers, final String[] args) { // add options (ie cmd line flags) final Options options = new Options(); for (final OptionHandler optionHandler : optionHandlers) { optionHandler.addOption(options); } // parse options from the cmd line final boolean parsedOk = parseAndPrimeWith(options, optionHandlers, args); if (parsedOk) { for (final OptionHandler optionHandler : optionHandlers) { primeWith(optionHandler); } } return parsedOk; } private boolean parseAndPrimeWith(final Options options, final List<OptionHandler> optionHandlers, final String[] args) { final BootPrinter printer = new BootPrinter(getClass()); final CommandLineParser parser = new BasicParser(); try { final CommandLine commandLine = parser.parse(options, args); for (final OptionHandler optionHandler : optionHandlers) { if (!optionHandler.handle(commandLine, printer, options)) { return false; } } } catch (final ParseException e) { printer.printErrorMessage(e.getMessage()); printer.printHelp(options); return false; } return true; } public interface Primer { void prime(IsisConfigurationBuilder isisConfigurationBuilder); } public void primeWith(final Primer primer) { ensureNotLocked(); LOG.debug("priming configurations for '{}'", primer); primer.prime(this); } //endregion //region > getConfiguration, peekConfiguration, isLocked /** * Returns the {@link IsisConfiguration}; this will cause the configuration to be locked */ public IsisConfigurationDefault getConfiguration() { if (!locked) { locked = true; dumpResourcesToLog(); } return configuration; } /** * Set once {@link #getConfiguration()} is called. */ public boolean isLocked() { return locked; } /** * Creates a copy of the current {@link #getConfiguration()}, without locking. * * <p> * Used while bootstrapping, to obtain the web.server port etc. * </p> */ public IsisConfiguration peekConfiguration() { IsisConfigurationDefault cfg = new IsisConfigurationDefault(resourceStreamSourceChain); // no locking Properties props = new Properties(); props.putAll(configuration.asMap()); cfg.add(props, ContainsPolicy.OVERWRITE); return cfg; } private void ensureNotLocked() { if (locked) { throw new IsisException("Configuration has been locked and cannot be changed"); } } //endregion //region > dumpResourcesToLog, toString /** * Log a summary of resources found or not found. */ public void dumpResourcesToLog() { if (LOG.isDebugEnabled()) { LOG.debug("Configuration resources FOUND:"); for (String resource : configurationResourcesFound) { LOG.debug("* {}", resource); } LOG.debug("Configuration resources NOT FOUND (but not needed):"); for (String resource : configurationResourcesNotFound) { LOG.debug("* {}", resource); } } } @Override public String toString() { return Objects.toStringHelper(this).add("resourceStream", resourceStreamSourceChain) .add("configResources", configurationResourcesFound).toString(); } //endregion }