Commons IO example source code file (DirectoryWalkerTestCase.java)

This example Commons IO source code file (DirectoryWalkerTestCase.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 - Commons IO tags/keywords

collection, dir, dir, file, file, io, ioexception, iofilefilter, list, list, override, result, size, testfilefinder, testfilefinder, util

The Commons IO DirectoryWalkerTestCase.java source code

/*
 * 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.commons.io;

import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

import junit.framework.Assert;
import junit.framework.TestCase;

import org.apache.commons.io.filefilter.FileFilterUtils;
import org.apache.commons.io.filefilter.IOFileFilter;
import org.apache.commons.io.filefilter.NameFileFilter;
import org.apache.commons.io.filefilter.OrFileFilter;

/**
 * This is used to test DirectoryWalker for correctness.
 *
 * @version $Id: DirectoryWalkerTestCase.java 1004358 2010-10-04 18:54:36Z niallp $
 * @see DirectoryWalker
 *
 */
public class DirectoryWalkerTestCase extends TestCase {

    // Directories
    private static final File current      = new File(".");
    private static final File javaDir      = new File("src/main/java");
    private static final File orgDir       = new File(javaDir, "org");
    private static final File apacheDir    = new File(orgDir, "apache");
    private static final File commonsDir   = new File(apacheDir, "commons");
    private static final File ioDir        = new File(commonsDir, "io");
    private static final File outputDir    = new File(ioDir, "output");
    private static final File[] dirs       = new File[] {orgDir, apacheDir, commonsDir, ioDir, outputDir};

    // Files
    private static final File filenameUtils = new File(ioDir, "FilenameUtils.java");
    private static final File ioUtils       = new File(ioDir, "IOUtils.java");
    private static final File proxyWriter   = new File(outputDir, "ProxyWriter.java");
    private static final File nullStream    = new File(outputDir, "NullOutputStream.java");
    private static final File[] ioFiles     = new File[] {filenameUtils, ioUtils};
    private static final File[] outputFiles = new File[] {proxyWriter, nullStream};
    
    // Filters
    private static final IOFileFilter dirsFilter        = createNameFilter(dirs);
    private static final IOFileFilter iofilesFilter     = createNameFilter(ioFiles);
    private static final IOFileFilter outputFilesFilter = createNameFilter(outputFiles);
    private static final IOFileFilter ioDirAndFilesFilter = new OrFileFilter(dirsFilter, iofilesFilter);
    private static final IOFileFilter dirsAndFilesFilter = new OrFileFilter(ioDirAndFilesFilter, outputFilesFilter);

    // Filter to exclude SVN files
    private static final IOFileFilter NOT_SVN = FileFilterUtils.makeSVNAware(null);

    /** Construct the TestCase using the name */
    public DirectoryWalkerTestCase(String name) {
        super(name);
    }

    /** Set Up */
    @Override
    protected void setUp() throws Exception {
        super.setUp();
    }

    /** Tear Down */
    @Override
    protected void tearDown() throws Exception {
        super.tearDown();
    }

    //-----------------------------------------------------------------------

    /**
     * Test Filtering
     */
    public void testFilter() {
        List<File> results = new TestFileFinder(dirsAndFilesFilter, -1).find(javaDir);
        assertEquals("Result Size", (1 + dirs.length + ioFiles.length + outputFiles.length), results.size());
        assertTrue("Start Dir", results.contains(javaDir));
        checkContainsFiles("Dir", dirs, results);
        checkContainsFiles("IO File", ioFiles, results);
        checkContainsFiles("Output File", outputFiles, results);
    }

    /**
     * Test Filtering and limit to depth 0
     */
    public void testFilterAndLimitA() {
        List<File> results = new TestFileFinder(NOT_SVN, 0).find(javaDir);
        assertEquals("[A] Result Size", 1, results.size());
        assertTrue("[A] Start Dir",   results.contains(javaDir));
    }

    /**
     * Test Filtering and limit to depth 1
     */
    public void testFilterAndLimitB() {
        List<File> results = new TestFileFinder(NOT_SVN, 1).find(javaDir);
        assertEquals("[B] Result Size", 2, results.size());
        assertTrue("[B] Start Dir",   results.contains(javaDir));
        assertTrue("[B] Org Dir",     results.contains(orgDir));
    }

    /**
     * Test Filtering and limit to depth 3
     */
    public void testFilterAndLimitC() {
        List<File> results = new TestFileFinder(NOT_SVN, 3).find(javaDir);
        assertEquals("[C] Result Size", 4, results.size());
        assertTrue("[C] Start Dir",   results.contains(javaDir));
        assertTrue("[C] Org Dir",     results.contains(orgDir));
        assertTrue("[C] Apache Dir",  results.contains(apacheDir));
        assertTrue("[C] Commons Dir", results.contains(commonsDir));
    }

    /**
     * Test Filtering and limit to depth 5
     */
    public void testFilterAndLimitD() {
        List<File> results = new TestFileFinder(dirsAndFilesFilter, 5).find(javaDir);
        assertEquals("[D] Result Size", (1 + dirs.length + ioFiles.length), results.size());
        assertTrue("[D] Start Dir", results.contains(javaDir));
        checkContainsFiles("[D] Dir", dirs, results);
        checkContainsFiles("[D] File", ioFiles, results);
    }

    /**
     * Test separate dir and file filters
     */
    public void testFilterDirAndFile1() {
        List<File> results = new TestFileFinder(dirsFilter, iofilesFilter, -1).find(javaDir);
        assertEquals("[DirAndFile1] Result Size", (1 + dirs.length + ioFiles.length), results.size());
        assertTrue("[DirAndFile1] Start Dir", results.contains(javaDir));
        checkContainsFiles("[DirAndFile1] Dir", dirs, results);
        checkContainsFiles("[DirAndFile1] File", ioFiles, results);
    }

    /**
     * Test separate dir and file filters
     */
    public void testFilterDirAndFile2() {
        List<File> results = new TestFileFinder((IOFileFilter) null, (IOFileFilter) null, -1).find(javaDir);
        assertTrue("[DirAndFile2] Result Size", results.size() > (1 + dirs.length + ioFiles.length));
        assertTrue("[DirAndFile2] Start Dir", results.contains(javaDir));
        checkContainsFiles("[DirAndFile2] Dir", dirs, results);
        checkContainsFiles("[DirAndFile2] File", ioFiles, results);
    }

    /**
     * Test separate dir and file filters
     */
    public void testFilterDirAndFile3() {
        List<File> results = new TestFileFinder(dirsFilter, (IOFileFilter) null, -1).find(javaDir);
        List<File> resultDirs = directoriesOnly(results);
        assertEquals("[DirAndFile3] Result Size", (1 + dirs.length), resultDirs.size());
        assertTrue("[DirAndFile3] Start Dir", results.contains(javaDir));
        checkContainsFiles("[DirAndFile3] Dir", dirs, resultDirs);
    }

    /**
     * Test separate dir and file filters
     */
    public void testFilterDirAndFile4() {
        List<File> results = new TestFileFinder((IOFileFilter) null, iofilesFilter, -1).find(javaDir);
        List<File> resultFiles = filesOnly(results);
        assertEquals("[DirAndFile4] Result Size", ioFiles.length, resultFiles.size());
        assertTrue("[DirAndFile4] Start Dir", results.contains(javaDir));
        checkContainsFiles("[DirAndFile4] File", ioFiles, resultFiles);
    }

    /**
     * Test Limiting to current directory
     */
    public void testLimitToCurrent() {
        List<File> results = new TestFileFinder(null, 0).find(current);
        assertEquals("Result Size", 1, results.size());
        assertTrue("Current Dir", results.contains(new File(".")));
    }

    /**
     * test an invalid start directory
     */
    public void testMissingStartDirectory() {

        // TODO is this what we want with invalid directory?
        File invalidDir = new File("invalid-dir");
        List<File> results = new TestFileFinder(null, -1).find(invalidDir);
        assertEquals("Result Size", 1, results.size());
        assertTrue("Current Dir", results.contains(invalidDir));
 
        try {
            new TestFileFinder(null, -1).find(null);
            fail("Null start directory didn't throw Exception");
        } catch (NullPointerException ignore) {
            // expected result
        }
    }

    /**
     * test an invalid start directory
     */
    public void testHandleStartDirectoryFalse() {

        List<File> results = new TestFalseFileFinder(null, -1).find(current);
        assertEquals("Result Size", 0, results.size());

    }

    // ------------ Convenience Test Methods ------------------------------------

    /**
     * Check the files in the array are in the results list.
     */
    private void checkContainsFiles(String prefix, File[] files, Collection<File> results) {
        for (int i = 0; i < files.length; i++) {
            assertTrue(prefix + "["+i+"] " + files[i], results.contains(files[i]));
        }
    }

    private void checkContainsString(String prefix, File[] files, Collection<String> results) {
        for (int i = 0; i < files.length; i++) {
            assertTrue(prefix + "["+i+"] " + files[i], results.contains(files[i].toString()));
        }
    }

    /**
     * Extract the directories.
     */
    private List<File> directoriesOnly(Collection results) {
        List<File> list = new ArrayList(results.size());
        for (Iterator<File> it = results.iterator(); it.hasNext(); ) {
            File file = it.next();
            if (file.isDirectory()) {
                list.add(file);
            }
        }
        return list;
    }

    /**
     * Extract the files.
     */
    private List<File> filesOnly(Collection results) {
        List<File> list = new ArrayList(results.size());
        for (Iterator<File> it = results.iterator(); it.hasNext(); ) {
            File file = it.next();
            if (file.isFile()) {
                list.add(file);
            }
        }
        return list;
    }

    /**
     * Create an name filter containg the names of the files
     * in the array.
     */
    private static IOFileFilter createNameFilter(File[] files) {
        String[] names = new String[files.length];
        for (int i = 0; i < files.length; i++) {
            names[i] = files[i].getName();
        }
        return new NameFileFilter(names);
    }

    /**
     * Test Cancel
     */
    public void testCancel() {
        String cancelName = null;

        // Cancel on a file
        try {
            cancelName = "DirectoryWalker.java";
            new TestCancelWalker(cancelName, false).find(javaDir);
            fail("CancelException not thrown for '" + cancelName + "'");
        } catch (DirectoryWalker.CancelException cancel) {
            assertEquals("File:  " + cancelName,   cancelName, cancel.getFile().getName());
            assertEquals("Depth: " + cancelName,  5, cancel.getDepth());
        } catch(IOException ex) {
            fail("IOException: " + cancelName + " " + ex);
        }

        // Cancel on a directory
        try {
            cancelName = "commons";
            new TestCancelWalker(cancelName, false).find(javaDir);
            fail("CancelException not thrown for '" + cancelName + "'");
        } catch (DirectoryWalker.CancelException cancel) {
            assertEquals("File:  " + cancelName,   cancelName, cancel.getFile().getName());
            assertEquals("Depth: " + cancelName,  3, cancel.getDepth());
        } catch(IOException ex) {
            fail("IOException: " + cancelName + " " + ex);
        }

        // Suppress CancelException (use same file name as preceeding test)
        try {
            List<File> results = new TestCancelWalker(cancelName, true).find(javaDir);
            File lastFile = results.get(results.size() - 1);
            assertEquals("Suppress:  " + cancelName,   cancelName, lastFile.getName());
        } catch(IOException ex) {
            fail("Suppress threw " + ex);
        }

    }

    /**
     * Test Cancel
     */
    public void testMultiThreadCancel() {
        String cancelName = "DirectoryWalker.java";
        TestMultiThreadCancelWalker walker = new TestMultiThreadCancelWalker(cancelName, false);
        // Cancel on a file
        try {
            walker.find(javaDir);
            fail("CancelException not thrown for '" + cancelName + "'");
        } catch (DirectoryWalker.CancelException cancel) {
            File last = walker.results.get(walker.results.size() - 1);
            assertEquals(cancelName, last.getName());
            assertEquals("Depth: " + cancelName,  5, cancel.getDepth());
        } catch(IOException ex) {
            fail("IOException: " + cancelName + " " + ex);
        }
        
        // Cancel on a directory
        try {
            cancelName = "commons";
            walker = new TestMultiThreadCancelWalker(cancelName, false);
            walker.find(javaDir);
            fail("CancelException not thrown for '" + cancelName + "'");
        } catch (DirectoryWalker.CancelException cancel) {
            assertEquals("File:  " + cancelName,   cancelName, cancel.getFile().getName());
            assertEquals("Depth: " + cancelName,  3, cancel.getDepth());
        } catch(IOException ex) {
            fail("IOException: " + cancelName + " " + ex);
        }
        
        // Suppress CancelException (use same file name as preceeding test)
        try {
            walker = new TestMultiThreadCancelWalker(cancelName, true);
            List<File> results = walker.find(javaDir);
            File lastFile = results.get(results.size() - 1);
            assertEquals("Suppress:  " + cancelName, cancelName, lastFile.getName());
        } catch(IOException ex) {
            fail("Suppress threw " + ex);
        }

    }

    /**
     * Test Filtering
     */
    public void testFilterString() {
        List<String> results = new TestFileFinderString(dirsAndFilesFilter, -1).find(javaDir);
        assertEquals("Result Size", (outputFiles.length + ioFiles.length), results.size());
        checkContainsString("IO File", ioFiles, results);
        checkContainsString("Output File", outputFiles, results);
    }

    // ------------ Test DirectoryWalker implementation --------------------------

    /**
     * Test DirectoryWalker implementation that finds files in a directory hierarchy
     * applying a file filter.
     */
    private static class TestFileFinder extends DirectoryWalker<File> {

        protected TestFileFinder(FileFilter filter, int depthLimit) {
            super(filter, depthLimit);
        }

        protected TestFileFinder(IOFileFilter dirFilter, IOFileFilter fileFilter, int depthLimit) {
            super(dirFilter, fileFilter, depthLimit);
        }

        /** find files. */
        protected List<File> find(File startDirectory) {
           List<File> results = new ArrayList();
           try {
               walk(startDirectory, results);
           } catch(IOException ex) {
               Assert.fail(ex.toString());
           }
           return results;
        }

        /** Handles a directory end by adding the File to the result set. */
        @Override
        protected void handleDirectoryEnd(File directory, int depth, Collection<File> results) {
            results.add(directory);
        }

        /** Handles a file by adding the File to the result set. */
        @Override
        protected void handleFile(File file, int depth, Collection<File> results) {
            results.add(file);
        }
    }

    // ------------ Test DirectoryWalker implementation --------------------------

    /**
     * Test DirectoryWalker implementation that always returns false
     * from handleDirectoryStart()
     */
    private static class TestFalseFileFinder extends TestFileFinder {

        protected TestFalseFileFinder(FileFilter filter, int depthLimit) {
            super(filter, depthLimit);
        }

        /** Always returns false. */
        @Override
        protected boolean handleDirectory(File directory, int depth, Collection<File> results) {
            return false;
        }
    }

    // ------------ Test DirectoryWalker implementation --------------------------

    /**
     * Test DirectoryWalker implementation that finds files in a directory hierarchy
     * applying a file filter.
     */
    static class TestCancelWalker extends DirectoryWalker<File> {
        private String cancelFileName;
        private boolean suppressCancel;

        TestCancelWalker(String cancelFileName,boolean suppressCancel) {
            super();
            this.cancelFileName = cancelFileName;
            this.suppressCancel = suppressCancel;
        }

        /** find files. */
        protected List<File> find(File startDirectory) throws IOException {
           List<File> results = new ArrayList();
           walk(startDirectory, results);
           return results;
        }

        /** Handles a directory end by adding the File to the result set. */
        @Override
        protected void handleDirectoryEnd(File directory, int depth, Collection<File> results) throws IOException {
            results.add(directory);
            if (cancelFileName.equals(directory.getName())) {
                throw new CancelException(directory, depth);
            }
        }

        /** Handles a file by adding the File to the result set. */
        @Override
        protected void handleFile(File file, int depth, Collection<File> results) throws IOException {
            results.add(file);
            if (cancelFileName.equals(file.getName())) {
                throw new CancelException(file, depth);
            }
        }

        /** Handles Cancel. */
        @Override
        protected void handleCancelled(File startDirectory, Collection<File> results,
                       CancelException cancel) throws IOException {
            if (!suppressCancel) {
                super.handleCancelled(startDirectory, results, cancel);
            }
        }
    }

    /**
     * Test DirectoryWalker implementation that finds files in a directory hierarchy
     * applying a file filter.
     */
    static class TestMultiThreadCancelWalker extends DirectoryWalker<File> {
        private String cancelFileName;
        private boolean suppressCancel;
        private boolean cancelled;
        public List<File> results;

        TestMultiThreadCancelWalker(String cancelFileName, boolean suppressCancel) {
            super();
            this.cancelFileName = cancelFileName;
            this.suppressCancel = suppressCancel;
        }

        /** find files. */
        protected List<File> find(File startDirectory) throws IOException {
           results = new ArrayList<File>();
           walk(startDirectory, results);
           return results;
        }

        /** Handles a directory end by adding the File to the result set. */
        @Override
        protected void handleDirectoryEnd(File directory, int depth, Collection<File> results) throws IOException {
            results.add(directory);
            assertEquals(false, cancelled);
            if (cancelFileName.equals(directory.getName())) {
                cancelled = true;
            }
        }

        /** Handles a file by adding the File to the result set. */
        @Override
        protected void handleFile(File file, int depth, Collection<File> results) throws IOException {
            results.add(file);
            assertEquals(false, cancelled);
            if (cancelFileName.equals(file.getName())) {
                cancelled = true;
            }
        }

        /** Handles Cancelled. */
        @Override
        protected boolean handleIsCancelled(File file, int depth, Collection<File> results) throws IOException {
            return cancelled;
        }

        /** Handles Cancel. */
        @Override
        protected void handleCancelled(File startDirectory, Collection<File> results,
                       CancelException cancel) throws IOException {
            if (!suppressCancel) {
                super.handleCancelled(startDirectory, results, cancel);
            }
        }
    }

    /**
     * Test DirectoryWalker implementation that finds files in a directory hierarchy
     * applying a file filter.
     */
    private static class TestFileFinderString extends DirectoryWalker<String> {

        protected TestFileFinderString(FileFilter filter, int depthLimit) {
            super(filter, depthLimit);
        }

        /** find files. */
        protected List<String> find(File startDirectory) {
           List<String> results = new ArrayList();
           try {
               walk(startDirectory, results);
           } catch(IOException ex) {
               Assert.fail(ex.toString());
           }
           return results;
        }

        /** Handles a file by adding the File to the result set. */
        @Override
        protected void handleFile(File file, int depth, Collection<String> results) {
            results.add(file.toString());
        }
    }

}