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.jackrabbit.standalone.cli; import java.util.ArrayList; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import java.util.Map; import org.apache.commons.chain.Catalog; import org.apache.commons.chain.Command; import org.apache.commons.chain.Context; import org.apache.commons.chain.config.ConfigParser; import org.apache.commons.chain.impl.CatalogFactoryBase; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * Input Parser */ public class JcrParser { /** parser */ private static Log log = LogFactory.getLog(JcrParser.class); static { try { ConfigParser parser = new ConfigParser(); parser.parse(JcrParser.class.getResource("command.xml")); } catch (Exception e) { log.error("Failed to parse command.xml", e); } } /** catalog */ private Catalog catalog = CatalogFactoryBase.getInstance().getCatalog(); /** Command */ private Command cmd; /** Command Line */ private CommandLine cl; /** * Constructor */ public JcrParser() { super(); } /** * Parse the user's input. * @param input * user's input * @throws JcrParserException * if the input is illegal * @throws ConfigurationException * if the mapped command can't be mapped to a Commons Chain Command */ public void parse(String input) throws JcrParserException, ConfigurationException { this.cl = null; this.cmd = null; // Validate input if (input == null || input.length() == 0) { throw new JcrParserException("exception.parse.input.empty"); } // Extract arguments LinkedList args = this.getArguments(input); // The first arg is the command name String cmdName = (String) args.getFirst(); args.removeFirst(); // Get the command line descriptor cl = CommandLineFactory.getInstance().getCommandLine(cmdName); // populate with the given params populate(cl, args); // validate the command line validate(cl); // Create Chain Command String impl = cl.getImpl(); if (impl == null) { impl = cl.getName(); } cmd = catalog.getCommand(impl); if (cmd == null) { throw new JcrParserException("no chain command for name " + impl); } } /** * Tokenize user's input * @param input * the user's input * @return a <code>List</code> containing the arguments */ private LinkedList getArguments(String input) { LinkedList args = new LinkedList(); int length = input.length(); boolean insideSingleQuote = false; boolean insideDoubleQuote = false; int escape = -1; StringBuffer arg = new StringBuffer(); for (int i = 0; i < length; ++i) { char c = input.charAt(i); // end of argument? if ((!insideSingleQuote && !insideDoubleQuote && Character.isWhitespace(c))) { if (arg.toString().trim().length() > 0) { args.add(arg.toString().trim()); arg = new StringBuffer(); } continue; } if (i == escape) { // escaped char arg.append(c); } else { // unescaped char switch (c) { case '\\': escape = i + 1; break; case '"': insideDoubleQuote = !insideDoubleQuote; break; case '\'': insideSingleQuote = !insideSingleQuote; break; default: arg.append(c); break; } } } if (arg.toString().trim().length() > 0) { args.add(arg.toString()); } return args; } /** * Populate the <code>Context</code> with the attributes needed by the * <code>Command</code> * @param ctx * the <code>Context</code> */ public void populateContext(Context ctx) { Iterator iter = cl.getAllParameters(); while (iter.hasNext()) { AbstractParameter param = (AbstractParameter) iter.next(); log.debug("add ctx attr: " + param.getContextKey() + "=" + param.getValue()); ctx.put(param.getContextKey(), param.getValue()); } } /** * Remove <code>Context</code> attribute specific to the parsed * <code>Command</code> * @param ctx * the <code>Context</code> */ public void depopulateContext(Context ctx) { Iterator iter = cl.getAllParameters(); while (iter.hasNext()) { AbstractParameter param = (AbstractParameter) iter.next(); String ctxKey = param.getContextKey(); log.debug("remove ctx attr: " + ctxKey + "=" + param.getValue()); ctx.remove(ctxKey); } } /** * @return the <code>Command</code> */ public Command getCommand() { return cmd; } /** * Populate the <code>CommandLine</code> with the given parameters * @param cl * the <code>CommandLine</code> * @param valList * the arguments * @throws JcrParserException * if the user's input is illegal */ private void populate(CommandLine cl, List valList) throws JcrParserException { String[] values = (String[]) valList.toArray(new String[valList.size()]); // Command Line parameters Map options = cl.getOptions(); Map flags = cl.getFlags(); Map clArgs = cl.getArguments(); // Input arguments List args = new ArrayList(); for (int i = 0; i < values.length; i++) { String value = values[i]; if (value.startsWith("-")) { // option if (i + 1 < values.length && !values[i + 1].startsWith("-")) { Option opt = (Option) options.get(value.substring(1)); if (opt == null) { throw new JcrParserException("exception.no.opt.for.name", new String[] { value.substring(1) }); } opt.setValue(values[i + 1]); i++; } else { // flag Flag flag = (Flag) flags.get(value.substring(1)); if (flag == null) { throw new JcrParserException("exception.no.flag.for.name", new String[] { value }); } flag.setPresent(true); } } else { // collect arguments args.add(value); } } // set arguments String[] argValues = (String[]) args.toArray(new String[args.size()]); for (int j = 0; j < argValues.length; j++) { Argument arg = (Argument) clArgs.get(new Integer(j)); if (arg == null) { throw new JcrParserException("exception.more.arguments.than.expected"); } arg.setValue(argValues[j]); } } /** * Validate the <code>CommandLine</code> * @param cl * the <code>CommandLine</code> * @throws JcrParserException * if a required parameter is not present in the user's input */ private void validate(CommandLine cl) throws JcrParserException { Iterator iter = cl.getRequiredParameters(); while (iter.hasNext()) { AbstractParameter param = (AbstractParameter) iter.next(); if (param.getValue() == null) { throw new JcrParserException("exception.missing.paramater", new String[] { param.getName() }); } } } }