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changes as per review comments

This commit is contained in:
Anurag Goyal 2019-04-11 19:06:41 +05:30
parent d9540eff75
commit fece0dc4b8
1 changed files with 111 additions and 119 deletions
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230
core-java-io/src/test/java/com/baeldung/filechannel/FileChannelUnitTest.java
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@ -12,162 +12,154 @@ import java.nio.ByteBuffer;
import java.nio.MappedByteBuffer; import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel; import java.nio.channels.FileChannel;
import java.nio.channels.FileLock; import java.nio.channels.FileLock;
import java.nio.channels.OverlappingFileLockException;
import java.nio.charset.StandardCharsets; import java.nio.charset.StandardCharsets;
import org.junit.Test; import org.junit.Test;
public class FileChannelUnitTest { public class FileChannelUnitTest {
@Test @Test
public void givenFile_whenReadWithFileChannelUsingRandomAccessFile_thenCorrect() throws IOException { public void givenFile_whenReadWithFileChannelUsingRandomAccessFile_thenCorrect() throws IOException {
try (RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "r"); try (RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "r");
FileChannel channel = reader.getChannel(); FileChannel channel = reader.getChannel();
ByteArrayOutputStream out = new ByteArrayOutputStream();) { ByteArrayOutputStream out = new ByteArrayOutputStream();) {
int bufferSize = 1024; int bufferSize = 1024;
if (bufferSize > channel.size()) { if (bufferSize > channel.size()) {
bufferSize = (int) channel.size(); bufferSize = (int) channel.size();
} }
ByteBuffer buff = ByteBuffer.allocate(bufferSize); ByteBuffer buff = ByteBuffer.allocate(bufferSize);
while (channel.read(buff) > 0) { while (channel.read(buff) > 0) {
out.write(buff.array(), 0, buff.position()); out.write(buff.array(), 0, buff.position());
buff.clear(); buff.clear();
} }
assertEquals("Hello world", new String(out.toByteArray(), StandardCharsets.UTF_8)); String fileContent = new String(out.toByteArray(), StandardCharsets.UTF_8);
}
}
@Test assertEquals("Hello world", fileContent);
public void givenFile_whenReadWithFileChannelUsingFileInputStream_thenCorrect() throws IOException { }
}
try (ByteArrayOutputStream out = new ByteArrayOutputStream(); @Test
FileInputStream fin = new FileInputStream("src/test/resources/test_read.in"); public void givenFile_whenReadWithFileChannelUsingFileInputStream_thenCorrect() throws IOException {
FileChannel channel = fin.getChannel();) {
int bufferSize = 1024; try (ByteArrayOutputStream out = new ByteArrayOutputStream();
if (bufferSize > channel.size()) { FileInputStream fin = new FileInputStream("src/test/resources/test_read.in");
bufferSize = (int) channel.size(); FileChannel channel = fin.getChannel();) {
}
ByteBuffer buff = ByteBuffer.allocate(bufferSize);
while (channel.read(buff) > 0) { int bufferSize = 1024;
out.write(buff.array(), 0, buff.position()); if (bufferSize > channel.size()) {
buff.clear(); bufferSize = (int) channel.size();
} }
ByteBuffer buff = ByteBuffer.allocate(bufferSize);
assertEquals("Hello world", new String(out.toByteArray(), StandardCharsets.UTF_8)); while (channel.read(buff) > 0) {
out.write(buff.array(), 0, buff.position());
buff.clear();
}
String fileContent = new String(out.toByteArray(), StandardCharsets.UTF_8);
} assertEquals("Hello world", fileContent);
} }
}
@Test @Test
public void givenFile_whenReadAFileSectionIntoMemoryWithFileChannel_thenCorrect() throws IOException { public void givenFile_whenReadAFileSectionIntoMemoryWithFileChannel_thenCorrect() throws IOException {
try (RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "r"); try (RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "r");
FileChannel channel = reader.getChannel(); FileChannel channel = reader.getChannel();
ByteArrayOutputStream out = new ByteArrayOutputStream();) { ByteArrayOutputStream out = new ByteArrayOutputStream();) {
MappedByteBuffer buff = channel.map(FileChannel.MapMode.READ_ONLY, 6, 5); MappedByteBuffer buff = channel.map(FileChannel.MapMode.READ_ONLY, 6, 5);
if (buff.hasRemaining()) { if (buff.hasRemaining()) {
byte[] data = new byte[buff.remaining()]; byte[] data = new byte[buff.remaining()];
buff.get(data); buff.get(data);
assertEquals("world", new String(data, StandardCharsets.UTF_8)); assertEquals("world", new String(data, StandardCharsets.UTF_8));
}
}
}
} @Test
public void whenWriteWithFileChannelUsingRandomAccessFile_thenCorrect() throws IOException {
String file = "src/test/resources/test_write_using_filechannel.txt";
try (RandomAccessFile writer = new RandomAccessFile(file, "rw");
FileChannel channel = writer.getChannel();) {
ByteBuffer buff = ByteBuffer.wrap("Hello world".getBytes(StandardCharsets.UTF_8));
} channel.write(buff);
}
@Test // now we verify whether the file was written correctly
public void whenWriteWithFileChannelUsingRandomAccessFile_thenCorrect() throws IOException { RandomAccessFile reader = new RandomAccessFile(file, "r");
String file = "src/test/resources/test_write_using_filechannel.txt"; assertEquals("Hello world", reader.readLine());
try (RandomAccessFile writer = new RandomAccessFile(file, "rw"); reader.close();
FileChannel channel = writer.getChannel();) { }
ByteBuffer buff = ByteBuffer.wrap("Hello world".getBytes(StandardCharsets.UTF_8)); }
if (buff.hasRemaining()) { @Test
channel.write(buff); public void givenFile_whenWriteAFileUsingLockAFileSectionWithFileChannel_thenCorrect() throws IOException {
} try (RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "rw");
FileChannel channel = reader.getChannel();
FileLock fileLock = channel.tryLock(6, 5, Boolean.FALSE);) {
// verify assertNotNull(fileLock);
RandomAccessFile reader = new RandomAccessFile(file, "r"); }
assertEquals("Hello world", reader.readLine()); }
reader.close();
}
}
@Test @Test
public void givenFile_whenWriteAFileUsingLockAFileSectionWithFileChannel_thenCorrect() throws IOException { public void givenFile_whenReadWithFileChannelGetPosition_thenCorrect() throws IOException {
try (RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "rw");
FileChannel channel = reader.getChannel();
FileLock fileLock = channel.tryLock(6, 5, Boolean.FALSE);) {
assertNotNull(fileLock); try (ByteArrayOutputStream out = new ByteArrayOutputStream();
RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "r");
FileChannel channel = reader.getChannel();) {
} catch (OverlappingFileLockException | IOException ex) { int bufferSize = 1024;
if (bufferSize > channel.size()) {
bufferSize = (int) channel.size();
}
ByteBuffer buff = ByteBuffer.allocate(bufferSize);
} while (channel.read(buff) > 0) {
out.write(buff.array(), 0, buff.position());
buff.clear();
}
} // the original file is 11 bytes long, so that's where the position pointer should be
assertEquals(11, channel.position());
@Test channel.position(4);
public void givenFile_whenReadWithFileChannelGetPosition_thenCorrect() throws IOException { assertEquals(4, channel.position());
}
}
try (ByteArrayOutputStream out = new ByteArrayOutputStream(); @Test
RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "r"); public void whenGetFileSize_thenCorrect() throws IOException {
FileChannel channel = reader.getChannel();) {
int bufferSize = 1024; try (RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "r");
if (bufferSize > channel.size()) { FileChannel channel = reader.getChannel();) {
bufferSize = (int) channel.size();
}
ByteBuffer buff = ByteBuffer.allocate(bufferSize);
while (channel.read(buff) > 0) { // the original file is 11 bytes long, so that's where the position pointer should be
out.write(buff.array(), 0, buff.position()); assertEquals(11, channel.size());
buff.clear(); }
} }
assertEquals(11, channel.position()); @Test
public void whenTruncateFile_thenCorrect() throws IOException {
String input = "this is a test input";
channel.position(4); FileOutputStream fout = new FileOutputStream("src/test/resources/test_truncate.txt");
assertEquals(4, channel.position()); FileChannel channel = fout.getChannel();
} ByteBuffer buff = ByteBuffer.wrap(input.getBytes());
} channel.write(buff);
buff.flip();
@Test channel = channel.truncate(5);
public void whenGetFileSize_thenCorrect() throws IOException { assertEquals(5, channel.size());
try (RandomAccessFile reader = new RandomAccessFile("src/test/resources/test_read.in", "r"); fout.close();
FileChannel channel = reader.getChannel();) { channel.close();
}
long imageFileSize = channel.size();
assertEquals(11, imageFileSize);
}
}
@Test
public void whenTruncateFile_thenCorrect() throws IOException {
String input = "this is a test input";
FileOutputStream fout = new FileOutputStream("src/test/resources/test_truncate.txt");
FileChannel channel = fout.getChannel();
ByteBuffer buff = ByteBuffer.wrap(input.getBytes());
channel.write(buff);
buff.flip();
channel = channel.truncate(5);
assertEquals(5, channel.size());
fout.close();
channel.close();
}
} }