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.openejb.util; import org.apache.commons.cli.CommandLine; import org.apache.commons.cli.HelpFormatter; import org.apache.commons.cli.OptionBuilder; import org.apache.commons.cli.Options; import org.apache.commons.cli.ParseException; import org.apache.commons.cli.PosixParser; import org.apache.openejb.cli.SystemExitException; import java.lang.reflect.Method; import java.lang.reflect.Modifier; import java.util.Collection; import java.util.Collections; import java.util.LinkedList; import java.util.List; // this helps to know which setters/properties we can use for nor owned code (OracleXaDataSource is a perfect example) public final class ListSetters { public static void main(final String[] args) throws Exception { final Options options = new Options(); options.addOption(OptionBuilder.isRequired(true).hasArg(true).withLongOpt("class") .withDescription("the class to introspect").create("c")); final CommandLine line; try { line = new PosixParser().parse(options, args); } catch (final ParseException exp) { help(options); throw new SystemExitException(-1); } if (line.hasOption("help")) { help(options); return; } final String clazz = line.getOptionValue("class"); final Collection<Class<?>> ancestors = Classes .ancestors(Thread.currentThread().getContextClassLoader().loadClass(clazz)); final List<String> list = new LinkedList<>(); for (final Class<?> c : ancestors) { for (final Method m : c.getDeclaredMethods()) { if (!Modifier.isPublic(m.getModifiers())) { continue; } if (!m.getName().startsWith("set")) { continue; } if (m.getGenericParameterTypes().length != 1) { continue; } list.add(m.getName().substring(3)); } } Collections.sort(list); for (final String s : list) { System.out.println("- " + s); } } private static void help(final Options options) { new HelpFormatter().printHelp("setters [options] <value>", "\n", options, "\n"); } private ListSetters() { // no-op } }