Java example source code file (SearchPath.java)

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

Learn more about this Java project at its project page.

Java - Java tags/keywords

arraylist, file, filenamefilter, searchpath, sortedset, string, stringtokenizer, treeset, util

The SearchPath.java Java example source code

/*
 * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * This source code is provided to illustrate the usage of a given feature
 * or technique and has been deliberately simplified. Additional steps
 * required for a production-quality application, such as security checks,
 * input validation and proper error handling, might not be present in
 * this sample code.
 */


package com.sun.tools.example.debug.gui;

import java.io.*;
import java.util.*;

public class SearchPath {

    private String pathString;

    private String[] pathArray;

    public SearchPath(String searchPath) {
        //### Should check searchpath for well-formedness.
        StringTokenizer st = new StringTokenizer(searchPath, File.pathSeparator);
        List<String> dlist = new ArrayList();
        while (st.hasMoreTokens()) {
            dlist.add(st.nextToken());
        }
        pathString = searchPath;
        pathArray = dlist.toArray(new String[dlist.size()]);
    }

    public boolean isEmpty() {
        return (pathArray.length == 0);
    }

    public String asString() {
        return pathString;
    }

    public String[] asArray() {
        return pathArray.clone();
    }

    public File resolve(String relativeFileName) {
        for (String element : pathArray) {
            File path = new File(element, relativeFileName);
            if (path.exists()) {
                return path;
            }
        }
        return null;
    }

    //### return List?

    public String[] children(String relativeDirName, FilenameFilter filter) {
        // If a file appears at the same relative path
        // with respect to multiple entries on the classpath,
        // the one corresponding to the earliest entry on the
        // classpath is retained.  This is the one that will be
        // found if we later do a 'resolve'.
        SortedSet<String> s = new TreeSet();  // sorted, no duplicates
        for (String element : pathArray) {
            File path = new File(element, relativeDirName);
            if (path.exists()) {
                String[] childArray = path.list(filter);
                if (childArray != null) {
                    for (int j = 0; j < childArray.length; j++) {
                        if (!s.contains(childArray[j])) {
                            s.add(childArray[j]);
                        }
                    }
                }
            }
        }
        return s.toArray(new String[s.size()]);
    }

}