Android example source code file (FileUtilsTest.java)

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

Java - Android tags/keywords

abcde, android, content, exception, file, filenotfoundexception, fileoutputstream, filestatus, fileutilstest, filewriter, io, ioexception, mediumtest, os, override, string, test, unexpected, zero

The FileUtilsTest.java Android example source code

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed 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 android.os;

import android.content.Context;
import android.os.FileUtils;
import android.os.FileUtils.FileStatus;
import android.test.AndroidTestCase;
import android.test.suitebuilder.annotation.LargeTest;
import android.test.suitebuilder.annotation.MediumTest;
import android.test.suitebuilder.annotation.SmallTest;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileWriter;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import junit.framework.Assert;

public class FileUtilsTest extends AndroidTestCase {
    private static final String TEST_DATA =
            "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

    private File mTestFile;
    private File mCopyFile;

    @Override
    protected void setUp() throws Exception {
        super.setUp();
        File testDir = getContext().getDir("testing", Context.MODE_PRIVATE);
        mTestFile = new File(testDir, "test.file");
        mCopyFile = new File(testDir, "copy.file");
        FileWriter writer = new FileWriter(mTestFile);
        try {
            writer.write(TEST_DATA, 0, TEST_DATA.length());
        } finally {
            writer.close();
        }
    }

    @Override
    protected void tearDown() throws Exception {
        if (mTestFile.exists()) mTestFile.delete();
        if (mCopyFile.exists()) mCopyFile.delete();
    }

    @LargeTest
    public void testGetFileStatus() {
        final byte[] MAGIC = { 0xB, 0xE, 0x0, 0x5 };

        try {
            // truncate test file and write MAGIC (4 bytes) to it.
            FileOutputStream os = new FileOutputStream(mTestFile, false);
            os.write(MAGIC, 0, 4);
            os.flush();
            os.close();
        } catch (FileNotFoundException e) {
            Assert.fail("File was removed durning test" + e);
        } catch (IOException e) {
            Assert.fail("Unexpected IOException: " + e);
        }
        
        Assert.assertTrue(mTestFile.exists());
        Assert.assertTrue(FileUtils.getFileStatus(mTestFile.getPath(), null));
        
        FileStatus status1 = new FileStatus();
        FileUtils.getFileStatus(mTestFile.getPath(), status1);
        
        Assert.assertEquals(4, status1.size);
        
        // Sleep for at least one second so that the modification time will be different.
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
        }

        try {
            // append so we don't change the creation time.
            FileOutputStream os = new FileOutputStream(mTestFile, true);
            os.write(MAGIC, 0, 4);
            os.flush();
            os.close();
        } catch (FileNotFoundException e) {
            Assert.fail("File was removed durning test" + e);
        } catch (IOException e) {
            Assert.fail("Unexpected IOException: " + e);
        }
        
        FileStatus status2 = new FileStatus();
        FileUtils.getFileStatus(mTestFile.getPath(), status2);
        
        Assert.assertEquals(8, status2.size);
        Assert.assertTrue(status2.mtime > status1.mtime);
        
        mTestFile.delete();
        
        Assert.assertFalse(mTestFile.exists());
        Assert.assertFalse(FileUtils.getFileStatus(mTestFile.getPath(), null));
    }

    // TODO: test setPermissions(), getPermissions()

    @MediumTest
    public void testCopyFile() throws Exception {
        assertFalse(mCopyFile.exists());
        FileUtils.copyFile(mTestFile, mCopyFile);
        assertTrue(mCopyFile.exists());
        assertEquals(TEST_DATA, FileUtils.readTextFile(mCopyFile, 0, null));
    }

    @MediumTest
    public void testCopyToFile() throws Exception {
        final String s = "Foo Bar";
        assertFalse(mCopyFile.exists());
        FileUtils.copyToFile(new ByteArrayInputStream(s.getBytes()), mCopyFile);        assertTrue(mCopyFile.exists());
        assertEquals(s, FileUtils.readTextFile(mCopyFile, 0, null));
    }

    @MediumTest
    public void testIsFilenameSafe() throws Exception {
        assertTrue(FileUtils.isFilenameSafe(new File("foobar")));
        assertTrue(FileUtils.isFilenameSafe(new File("a_b-c=d.e/0,1+23")));
        assertFalse(FileUtils.isFilenameSafe(new File("foo*bar")));
        assertFalse(FileUtils.isFilenameSafe(new File("foo\nbar")));
    }

    @MediumTest
    public void testReadTextFile() throws Exception {
        assertEquals(TEST_DATA, FileUtils.readTextFile(mTestFile, 0, null));

        assertEquals("ABCDE", FileUtils.readTextFile(mTestFile, 5, null));
        assertEquals("ABCDE<>", FileUtils.readTextFile(mTestFile, 5, "<>"));
        assertEquals(TEST_DATA.substring(0, 51) + "<>",
                FileUtils.readTextFile(mTestFile, 51, "<>"));
        assertEquals(TEST_DATA, FileUtils.readTextFile(mTestFile, 52, "<>"));
        assertEquals(TEST_DATA, FileUtils.readTextFile(mTestFile, 100, "<>"));

        assertEquals("vwxyz", FileUtils.readTextFile(mTestFile, -5, null));
        assertEquals("<>vwxyz", FileUtils.readTextFile(mTestFile, -5, "<>"));
        assertEquals("<>" + TEST_DATA.substring(1, 52),
                FileUtils.readTextFile(mTestFile, -51, "<>"));
        assertEquals(TEST_DATA, FileUtils.readTextFile(mTestFile, -52, "<>"));
        assertEquals(TEST_DATA, FileUtils.readTextFile(mTestFile, -100, "<>"));
    }

    @MediumTest
    public void testReadTextFileWithZeroLengthFile() throws Exception {
        new FileOutputStream(mTestFile).close();  // Zero out the file
        assertEquals("", FileUtils.readTextFile(mTestFile, 0, null));
        assertEquals("", FileUtils.readTextFile(mTestFile, 1, "<>"));
        assertEquals("", FileUtils.readTextFile(mTestFile, 10, "<>"));
        assertEquals("", FileUtils.readTextFile(mTestFile, -1, "<>"));
        assertEquals("", FileUtils.readTextFile(mTestFile, -10, "<>"));
    }
}