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.hadoop.hdfs; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import org.apache.commons.cli.CommandLine; import org.apache.commons.cli.CommandLineParser; import org.apache.commons.cli.Options; import org.apache.commons.cli.OptionBuilder; import org.apache.commons.cli.ParseException; import org.apache.commons.cli.PosixParser; public class AvatarShellCommand { private static String WRONG = " - wrong arguments: "; private static String CMD = "Command: "; private static List<String> safeModeActions = new ArrayList<String>(); static { safeModeActions.add("enter"); safeModeActions.add("leave"); safeModeActions.add("get"); safeModeActions.add("initqueues"); safeModeActions.add("prepfailover"); safeModeActions.add("get"); } // commands static final String waitTxIdCommand = "waittxid"; static final String failoverCommand = "failover"; static final String prepfailoverCommand = "prepfailover"; static final String metasaveCommand = "metasave"; static final String safemodeCommand = "safemode"; static final String setAvatarCommand = "setAvatar"; static final String isInitializedCommand = "isInitialized"; static final String shutdownAvatarCommand = "shutdownAvatar"; static final String showAvatarCommand = "showAvatar"; static final String saveNamespaceCommand = "saveNamespace"; // helpers static final String zeroCommand = "zero"; static final String oneCommand = "one"; static final String serviceCommand = "service"; static final String addressCommand = "address"; // commands boolean isWaitTxIdCommand; boolean isFailoverCommand; boolean isPrepfailoverCommand; boolean isMetasaveCommand; String[] metasageArgs; boolean isSafemodeCommand; String[] safemodeArgs; boolean isSetAvatarCommand; String[] setAvatarArgs; boolean isIsInitializedCommand; boolean isShutdownAvatarCommand; boolean isShowAvatarCommand; boolean isSaveNamespaceCommand; String[] saveNamespaceArgs; // helpers boolean isZeroCommand; boolean isOneCommand; boolean isServiceCommand; String[] serviceArgs; boolean isAddressCommand; String[] addressArgs; List<String> getSaveNamespaceArgs() { List<String> args = new ArrayList<String>(); if (saveNamespaceArgs != null) { for (String arg : saveNamespaceArgs) { args.add(arg); } } return args; } void throwException(String msg) { System.err.println(msg); throw new IllegalArgumentException(msg); } /** * For commands that directly obtain information from zk */ void noZeroOrOneOrAddress(String command) { if (isZeroCommand || isOneCommand) { throwException(CMD + command + " (zero|one) should not be specified"); } if (isAddressCommand) { throwException(CMD + command + " address should not be specified"); } } /** * Check if either -zero -one or -address are specified. */ void eitherZeroOrOneOrAddress(String command) { if (!isAddressCommand && !(isZeroCommand ^ isOneCommand)) { throwException(CMD + command + ": (zero|one) specified incorrectly"); } if (isAddressCommand && (isZeroCommand || isOneCommand)) { throwException(CMD + command + ": cannot specify address with (zero|one)"); } } private void assertArgsSize(String command, String[] args, int maxSize, int requiredSize) { if (args == null && requiredSize == 0) { return; } if (args.length < requiredSize || args.length > maxSize) { throwException(CMD + command + WRONG + Arrays.toString(args)); } } boolean validate(CommandLine cmd) { int commands = 0; commands += isWaitTxIdCommand ? 1 : 0; commands += isFailoverCommand ? 1 : 0; commands += isPrepfailoverCommand ? 1 : 0; commands += isMetasaveCommand ? 1 : 0; commands += isSafemodeCommand ? 1 : 0; commands += isSetAvatarCommand ? 1 : 0; commands += isIsInitializedCommand ? 1 : 0; commands += isShutdownAvatarCommand ? 1 : 0; commands += isShowAvatarCommand ? 1 : 0; commands += isSaveNamespaceCommand ? 1 : 0; if (commands > 1) { throwException("More than one command specified"); } if (isZeroCommand && isOneCommand) { throwException("Both zero and one specified"); } if ((isServiceCommand || isZeroCommand || isOneCommand) && isAddressCommand) { throwException("Both service|zero|one and address specified"); } // /////////////////////// complext commands // -waittxid if (isWaitTxIdCommand) { noZeroOrOneOrAddress(waitTxIdCommand); assertArgsSize(waitTxIdCommand, cmd.getOptionValues(waitTxIdCommand), 0, 0); } // -failover if (isFailoverCommand) { noZeroOrOneOrAddress(failoverCommand); assertArgsSize(failoverCommand, cmd.getOptionValues(failoverCommand), 0, 0); } // -prepfalover if (isPrepfailoverCommand) { noZeroOrOneOrAddress(prepfailoverCommand); assertArgsSize(prepfailoverCommand, cmd.getOptionValues(prepfailoverCommand), 0, 0); } // /////////////// per-avatar node commands // -showAvatar if (isShowAvatarCommand) { eitherZeroOrOneOrAddress(showAvatarCommand); assertArgsSize(showAvatarCommand, cmd.getOptionValues(showAvatarCommand), 0, 0); } // -shutDownAvatar if (isShutdownAvatarCommand) { eitherZeroOrOneOrAddress(shutdownAvatarCommand); assertArgsSize(shutdownAvatarCommand, cmd.getOptionValues(shutdownAvatarCommand), 0, 0); } // -isInitialized if (isIsInitializedCommand) { eitherZeroOrOneOrAddress(isInitializedCommand); assertArgsSize(isInitializedCommand, cmd.getOptionValues(isInitializedCommand), 0, 0); } // -setAvatar if (isSetAvatarCommand) { eitherZeroOrOneOrAddress(setAvatarCommand); setAvatarArgs = cmd.getOptionValues(setAvatarCommand); assertArgsSize(setAvatarCommand, setAvatarArgs, 2, 1); if (setAvatarArgs != null) { boolean hasPrimary = false; for (String arg : setAvatarArgs) { if (!(arg.equals("primary") || arg.equals("force"))) throwException(CMD + setAvatarCommand + WRONG + Arrays.toString(setAvatarArgs)); if (arg.equals("primary")) hasPrimary = true; } if (!hasPrimary) { throwException(CMD + setAvatarCommand + WRONG + Arrays.toString(setAvatarArgs)); } } } // -metasave if (isMetasaveCommand) { eitherZeroOrOneOrAddress(metasaveCommand); metasageArgs = cmd.getOptionValues(metasaveCommand); assertArgsSize(metasaveCommand, metasageArgs, 1, 1); } // -safemode if (isSafemodeCommand) { eitherZeroOrOneOrAddress(safemodeCommand); safemodeArgs = cmd.getOptionValues(safemodeCommand); assertArgsSize(safemodeCommand, safemodeArgs, 1, 1); for (String arg : safemodeArgs) { if (!safeModeActions.contains(arg)) throwException(CMD + safemodeCommand + " - safemode action: " + arg + " unknown"); } } // -saveNamespace if (isSaveNamespaceCommand) { eitherZeroOrOneOrAddress(saveNamespaceCommand); saveNamespaceArgs = cmd.getOptionValues(saveNamespaceCommand); assertArgsSize(saveNamespaceCommand, saveNamespaceArgs, 2, 0); if (saveNamespaceArgs != null) { for (String arg : saveNamespaceArgs) { if (!(arg.equals("uncompressed") || arg.equals("force"))) throwException(CMD + saveNamespaceCommand + WRONG + Arrays.toString(saveNamespaceArgs)); } } } // -service if (isServiceCommand) { serviceArgs = cmd.getOptionValues(serviceCommand); assertArgsSize(serviceCommand, serviceArgs, 1, 1); } // -address if (isAddressCommand) { addressArgs = cmd.getOptionValues(addressCommand); assertArgsSize(addressCommand, addressArgs, 1, 1); int i = addressArgs[0].indexOf(":"); if (i < 1) throwException(addressCommand + ": wrong host:port pair"); try { Integer.valueOf(addressArgs[0].substring(i + 1)); } catch (Exception e) { throwException(addressCommand + ": wrong host:port pair"); } } // -zero -one assertArgsSize(zeroCommand, cmd.getOptionValues(zeroCommand), 0, 0); assertArgsSize(oneCommand, cmd.getOptionValues(oneCommand), 0, 0); return true; } static AvatarShellCommand parseCommand(String[] argv) { CommandLine cmd = parseOptions(argv); if (cmd == null) return null; AvatarShellCommand asc = new AvatarShellCommand(); asc.isWaitTxIdCommand = cmd.hasOption(waitTxIdCommand); asc.isFailoverCommand = cmd.hasOption(failoverCommand); asc.isPrepfailoverCommand = cmd.hasOption(prepfailoverCommand); asc.isMetasaveCommand = cmd.hasOption(metasaveCommand); asc.isSafemodeCommand = cmd.hasOption(safemodeCommand); asc.isSetAvatarCommand = cmd.hasOption(setAvatarCommand); asc.isIsInitializedCommand = cmd.hasOption(isInitializedCommand); asc.isShutdownAvatarCommand = cmd.hasOption(shutdownAvatarCommand); asc.isShowAvatarCommand = cmd.hasOption(showAvatarCommand); asc.isSaveNamespaceCommand = cmd.hasOption(saveNamespaceCommand); asc.isZeroCommand = cmd.hasOption(zeroCommand); asc.isOneCommand = cmd.hasOption(oneCommand); asc.isServiceCommand = cmd.hasOption(serviceCommand); asc.isAddressCommand = cmd.hasOption(addressCommand); try { asc.validate(cmd); } catch (Exception e) { return null; } return asc; } private static CommandLine parseOptions(String[] argv) { Options options = buildOptions(); CommandLineParser parser = new PosixParser(); try { return parser.parse(options, argv); } catch (ParseException e) { System.out.println("Error parsing command-line options"); return null; } } /** * Build command-line options and descriptions */ @SuppressWarnings("static-access") public static Options buildOptions() { Options options = new Options(); // actual commands options.addOption(OptionBuilder.hasOptionalArgs().create(waitTxIdCommand)); options.addOption(OptionBuilder.hasOptionalArgs().create(failoverCommand)); options.addOption(OptionBuilder.hasOptionalArgs().create(prepfailoverCommand)); options.addOption(OptionBuilder.hasOptionalArgs().create(metasaveCommand)); options.addOption(OptionBuilder.hasOptionalArgs().create(safemodeCommand)); options.addOption(OptionBuilder.hasOptionalArgs().create(saveNamespaceCommand)); options.addOption(OptionBuilder.hasOptionalArgs().create(setAvatarCommand)); options.addOption(OptionBuilder.hasOptionalArgs().create(isInitializedCommand)); options.addOption(OptionBuilder.hasOptionalArgs().create(shutdownAvatarCommand)); options.addOption(OptionBuilder.hasOptionalArgs().create(showAvatarCommand)); // helper commands options.addOption(OptionBuilder.hasOptionalArgs().create(zeroCommand)); options.addOption(OptionBuilder.hasOptionalArgs().create(oneCommand)); options.addOption(OptionBuilder.hasOptionalArgs().create(serviceCommand)); options.addOption(OptionBuilder.hasOptionalArgs().create(addressCommand)); return options; } }