Glassfish example source code file (AgentArguments.java)

This example Glassfish source code file (AgentArguments.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Glassfish tags/keywords

agent_arg_pattern, agentarguments, agentarguments, arraylist, hashmap, keyword, keyword, list, list, map, matcher, regex, string, string, unquoted, util

The Glassfish AgentArguments.java source code

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2011 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package org.glassfish.appclient.client.acc;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.glassfish.appclient.client.CLIBootstrap;

/**
 * Self-contained scanner for an agent argument string.
 * <p>
 * The agent arguments are a comma-separated sequence of
 * <code>[keyword=]quoted-or-unquoted-string.
 * The "keyword=" part is optional.  A given keyword can 
 * appear multiple times, so after analysis each keyword can map
 * to potentially multiple values (as a List<String>).
 * <p>
 * This class organizes the agent arguments into named and anonymous values.
 *
 */
public class AgentArguments {

    /**
     * Pattern notes: The first group is non-capturing and tries to match the
     * keyword= part zero or one time.  The next group (*.*?) matches and captures
     * any keyword.  The ? immediately after that group means
     * 0 or 1 times.
     *
     * The next group is a quoted string not itself containing
     * a quotation mark.  The next group, an alternative (indicated by
     * the | mark) to the quoted string group, is a non-quoted string not containing a comma.
     * The pattern ends (non-capturing group) with an optional comma (could
     * be end-of-input so the comma is optional)
     */
//    private static final String AGENT_ARG_PATTERN = "(?:(.*?)=)?(?:\"([^\"]*)\"|([^,]+))(?:,?)";
    private static final String AGENT_ARG_PATTERN = "(?:([^=,]*?)=)?((?:\"([^\"]*)\")|[^,]+)";
    /* groups matching interesting parts of the regex */
    private static final int KEYWORD = 1;
    private static final int QUOTED = 2;
    private static final int UNQUOTED = 3;
    private static Pattern agentArgPattern = Pattern.compile(AGENT_ARG_PATTERN, Pattern.DOTALL);

    private final Map<String,List values = new HashMap>();

    public static AgentArguments newInstance(final String args) {
        AgentArguments result = new AgentArguments();
        result.scan(args);
        return result;
    }

    /**
     * Returns the list of values associated with the specified keyword.
     * @param keyword the keyword whose values are needed
     * @return the values associated with the keyword; null if the keyword never appeared in the input
     */
    public List<String> namedValues(final String keyword) {
        return actualOrEmptyList(keyword);
    }

    /**
     * Returns the unnamed values as a list of strings.
     * @return List of Strings, one for each unnamed value in the scanned string
     */
    public List<String> unnamedValues() {
        return actualOrEmptyList(null);
    }

    private List<String> actualOrEmptyList(final String keyword) {
        return (values.get(keyword) != null ? values.get(keyword) : Collections.EMPTY_LIST);
    }
    
    /**
     * Scans the input args string, updating the nameValuePairs properties
     * object using items with a keyword and updated the singleWordArgs list
     * with items without a keyword.
     *
     * @param args input line to scan
     * @param nameValuePairs properties to augment with keyword entries in the input
     * @param singleWordArgs list of strings to augment with un-keyworded entries in the input
     */
    private void scan(final String args) {
        if (args == null) {
            return;
        }
        Matcher m = agentArgPattern.matcher(args);
        while (m.find()) {
            final String keyword = m.group(KEYWORD);
            /*
             * Either the quoted string group or the unquoted string group
             * from the matcher will be valid.
             */
            final String value = CLIBootstrap.decodeArg(m.group(QUOTED) != null ? m.group(QUOTED) : m.group(UNQUOTED));
            getOrCreateValuesForKeyword(keyword).add(value);
        }
    }

    private List<String> getOrCreateValuesForKeyword(final String keyword) {
        List<String> result = values.get(keyword);
        if (result == null) {
            result = new ArrayList<String>();
            values.put(keyword, result);
        }
        return result;
    }
}