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Java example source code file (Utils.java)

This example Java source code file (Utils.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, foundcycle, ioexception, linkedlist, list, map, object, rec, regex, runtimeexception, set, string, substituter, suppresswarnings, util

The Utils.java Java example source code

/*
 * Copyright (c) 2011, 2012, 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.
 */
package com.apple.internal.jobjc.generator;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
import java.util.regex.Pattern;

import com.apple.internal.jobjc.generator.model.Framework;
import com.apple.internal.jobjc.generator.model.Framework.FrameworkDependency;
import com.apple.internal.jobjc.generator.utils.Fp;

public class Utils {
    public static boolean isLeopard = System.getProperty("os.version").startsWith("10.5");
    public static boolean isSnowLeopard = System.getProperty("os.version").startsWith("10.6");

    @SuppressWarnings("unchecked")
    public static <T> List list(final Object...args) {
        final ArrayList<Object> list = new ArrayList(args.length);
        for (final Object arg : args) list.add(arg);
        return (List<T>)list;
    }

    /**
     * A small implementation of UNIX find.
     * @param matchRegex Only collect paths that match this regex.
     * @param pruneRegex Don't recurse down a path that matches this regex. May be null.
     * @throws IOException if File.getCanonicalPath() fails.
     */
    public static List<File> find(final File startpath, final String matchRegex, final String pruneRegex) throws IOException{
        final Pattern matchPattern = Pattern.compile(matchRegex, Pattern.CASE_INSENSITIVE);
        final Pattern prunePattern = pruneRegex == null ? null : Pattern.compile(pruneRegex, Pattern.CASE_INSENSITIVE);
        final Set<String> visited = new HashSet();
        final List<File> found = new ArrayList();
        class Search{
            void search(final File path) throws IOException{
                if(prunePattern != null && prunePattern.matcher(path.getAbsolutePath()).matches()) return;
                String cpath = path.getCanonicalPath();
                if(!visited.add(cpath))  return;
                if(matchPattern.matcher(path.getAbsolutePath()).matches())
                    found.add(path);
                if(path.isDirectory())
                    for(File sub : path.listFiles())
                        search(sub);
            }
        }
        new Search().search(startpath);
        return found;
    }

    public static String joinWComma(final List<?> list) { return Fp.join(", ", list); }
    public static String joinWComma(final Object[] list) { return Fp.join(", ", Arrays.asList(list)); }

    public static class Substituter {
        String str;

        public Substituter(final String str) {
            this.str = str.replaceAll("\\#", "\t").replaceAll("\\~", "\n");
        }

        public void replace(final String key, final String value) {
            str = str.replaceAll("\\$" + key, value);
        }

        /**
         * Apply String.format first, and then pass through Substituter.
         */
        public static String format(String format, Object... args){
            return new Substituter(String.format(format, args)).toString();
        }

        @Override public String toString() {
            return str;
        }
    }

    static Map<String, String> getArgs(final String...args) {
        final Map<String, String> argMap = new HashMap();
        for (final String arg : args) {
            final String[] splitArg = arg.split("\\=");
            if (splitArg.length != 2) continue;
            argMap.put(splitArg[0], splitArg[1]);
        }
        return argMap;
    }

    static void recDelete(final File file) {
        if (!file.exists()) return;
        if (file.isDirectory()) for (final File f : file.listFiles()) recDelete(f);
        file.delete();
    }

    public static String capitalize(String s){
        if(s.length() == 0) return s;
        return Character.toString(Character.toUpperCase(s.charAt(0))) + s.substring(1);
    }

    /**
     * Sort frameworks by dependencies. If A is a dependency of B,
     * then A will come before B in the list.
     */
    public static void topologicalSort(final List<Framework> frameworks) {
        final Set<Framework> visited = new TreeSet();
        final List<Framework> sorted = new ArrayList(frameworks.size());
        class Rec{
            void visit(final Framework fw){
                if(!visited.add(fw)) return;
                for(FrameworkDependency dep : fw.dependencies)
                    if(dep.object != null)
                        visit(dep.object);
                sorted.add(fw);
            }
        }
        for(Framework fw : frameworks) new Rec().visit(fw);
        frameworks.clear();
        frameworks.addAll(sorted);
    }

    /**
     * If there is a cycle it is returned. Otherwise null is returned.
     */
    public static List<Framework> getDependencyCycle(List frameworks) {
        @SuppressWarnings("serial")
        class FoundCycle extends Throwable{
            public final List<Framework> cycle;
            public FoundCycle(List<Framework> cycle){
                this.cycle = cycle;
            }
        };
        class Rec{
            void visit(final Framework fw, List<Framework> visited) throws FoundCycle{
                visited = new LinkedList<Framework>(visited);
                if(visited.contains(fw)){
                    visited.add(fw);
                    throw new FoundCycle(visited);
                }
                visited.add(fw);
                for(FrameworkDependency dep : fw.dependencies)
                    if(dep.object != null)
                        visit(dep.object, visited);
            }
        }
        try{ for(Framework fw : frameworks){ new Rec().visit(fw, new LinkedList<Framework>()); }}
        catch(FoundCycle x){ return x.cycle; }
        return null;
    }

    public static String getCanonicalPath(File file) throws RuntimeException{
        try {
            return file.getCanonicalPath();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}




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