Java tutorial
/* * 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 my; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.io.PrintWriter; import java.io.Reader; import java.io.Writer; import java.util.Arrays; import junit.framework.AssertionFailedError; import junit.framework.TestCase; import static junit.framework.Assert.assertTrue; import static junit.framework.Assert.assertEquals; import org.apache.commons.io.FileUtils; import org.apache.commons.io.IOUtils; import org.apache.commons.io.output.ByteArrayOutputStream; /** * org.apache.commons.io.testtools.TestCase */ public abstract class FileBasedTestCase extends TestCase { //volatile????????testDir????? private static volatile File testDir; public FileBasedTestCase(String name) { super(name); } //vilatile????????????? //????????????volatile???????????? //Singleton public static File getTestDirectory() { if (testDir == null) { testDir = (new File("test/io/")).getAbsoluteFile(); } testDir.mkdirs(); return testDir; } protected void createFile(File file, long size) throws IOException { if (!file.getParentFile().exists()) { throw new IOException("Cannot create file " + file + " as the parent directory does not exist"); } BufferedOutputStream output = new BufferedOutputStream(new java.io.FileOutputStream(file)); try { generateTestData(output, size); } finally { IOUtils.closeQuietly(output); } } protected byte[] generateTestData(long size) { try { ByteArrayOutputStream baout = new ByteArrayOutputStream(); generateTestData(baout, size); return baout.toByteArray(); } catch (IOException ioe) { throw new RuntimeException("This should never happen: " + ioe.getMessage()); } } protected void generateTestData(OutputStream out, long size) throws IOException { for (int i = 0; i < size; i++) { //output.write((byte)'X'); // nice varied byte pattern compatible with Readers and Writers out.write((byte) ((i % 127) + 1)); } } protected void createLineBasedFile(File file, String[] data) throws IOException { if (file.getParentFile() != null && !file.getParentFile().exists()) { throw new IOException("Cannot create file " + file + " as the parent directory does not exist"); } PrintWriter output = new PrintWriter(new OutputStreamWriter(new FileOutputStream(file), "UTF-8")); try { for (int i = 0; i < data.length; i++) { output.println(data[i]); } } finally { IOUtils.closeQuietly(output); } } protected File newFile(String filename) throws IOException { File destination = new File(getTestDirectory(), filename); /* assertTrue( filename + "Test output data file shouldn't previously exist", !destination.exists() ); */ if (destination.exists()) { FileUtils.forceDelete(destination); } return destination; } protected void checkFile(File file, File referenceFile) throws Exception { assertTrue("Check existence of output file", file.exists()); assertEqualContent(referenceFile, file); } /** Assert that the content of two files is the same. */ private void assertEqualContent(File f0, File f1) throws IOException { /* This doesn't work because the filesize isn't updated until the file * is closed. assertTrue( "The files " + f0 + " and " + f1 + " have differing file sizes (" + f0.length() + " vs " + f1.length() + ")", ( f0.length() == f1.length() ) ); */ InputStream is0 = new java.io.FileInputStream(f0); try { InputStream is1 = new java.io.FileInputStream(f1); try { byte[] buf0 = new byte[1024]; byte[] buf1 = new byte[1024]; int n0 = 0; int n1 = 0; while (-1 != n0) { n0 = is0.read(buf0); n1 = is1.read(buf1); assertTrue("The files " + f0 + " and " + f1 + " have differing number of bytes available (" + n0 + " vs " + n1 + ")", (n0 == n1)); assertTrue("The files " + f0 + " and " + f1 + " have different content", Arrays.equals(buf0, buf1)); } } finally { is1.close(); } } finally { is0.close(); } } /** Assert that the content of a file is equal to that in a byte[]. */ protected void assertEqualContent(byte[] b0, File file) throws IOException { InputStream is = new java.io.FileInputStream(file); int count = 0, numRead = 0; byte[] b1 = new byte[b0.length]; try { while (count < b0.length && numRead >= 0) { numRead = is.read(b1, count, b0.length); count += numRead; } assertEquals("Different number of bytes: ", b0.length, count); for (int i = 0; i < count; i++) { assertEquals("byte " + i + " differs", b0[i], b1[i]); } } finally { is.close(); } } /** Assert that the content of a file is equal to that in a char[]. */ protected void assertEqualContent(char[] c0, File file) throws IOException { Reader ir = new java.io.FileReader(file); int count = 0, numRead = 0; char[] c1 = new char[c0.length]; try { while (count < c0.length && numRead >= 0) { numRead = ir.read(c1, count, c0.length); count += numRead; } assertEquals("Different number of chars: ", c0.length, count); for (int i = 0; i < count; i++) { assertEquals("char " + i + " differs", c0[i], c1[i]); } } finally { ir.close(); } } protected void checkWrite(OutputStream output) throws Exception { try { new java.io.PrintStream(output).write(0); } catch (Throwable t) { throw new AssertionFailedError( "The copy() method closed the stream " + "when it shouldn't have. " + t.getMessage()); } } protected void checkWrite(Writer output) throws Exception { try { new java.io.PrintWriter(output).write('a'); } catch (Throwable t) { throw new AssertionFailedError( "The copy() method closed the stream " + "when it shouldn't have. " + t.getMessage()); } } protected void deleteFile(File file) throws Exception { if (file.exists()) { assertTrue("Couldn't delete file: " + file, file.delete()); } } }