Java SeekableByteChannel.write方法代碼示例

import java.nio.channels.SeekableByteChannel; //導入方法依賴的package包/類
public static void xorFiles(SeekableByteChannel inputA, SeekableByteChannel inputB,
                            SeekableByteChannel outputChannel, long limit) throws IOException {
	ByteBuffer aBuffer = ByteBuffer.allocateDirect(BUFFER_SIZE);
	ByteBuffer bBuffer = ByteBuffer.allocateDirect(BUFFER_SIZE);
	ByteBuffer outBuffer = ByteBuffer.allocateDirect(BUFFER_SIZE);

	do {
		if (inputA.position() == inputA.size()) inputA.position(0);
		if (inputB.position() == inputB.size()) inputB.position(0);

		inputA.read(aBuffer);
		inputB.read(bBuffer);
		aBuffer.flip();
		bBuffer.flip();
		int cap = min(aBuffer.remaining(), bBuffer.remaining(), outBuffer.remaining());
		for (int i = 0; i < cap; i += 8) {
			long a = aBuffer.getLong();
			long b = bBuffer.getLong();
			outBuffer.putLong(a ^ b);
		}
		aBuffer.compact();
		bBuffer.compact();

		outBuffer.flip();
		long bytesRequired = limit - outputChannel.size();
		if (outBuffer.limit() > bytesRequired) outBuffer.limit((int) bytesRequired);
		outputChannel.write(outBuffer);
		outBuffer.compact();
	} while (outputChannel.size() < limit);
}
 

import java.nio.channels.SeekableByteChannel; //導入方法依賴的package包/類
private static SeekableByteChannel createNoClose(Path p)
        throws IOException {
    SeekableByteChannel newChan = Files.newByteChannel(
            p, StandardOpenOption.CREATE,
                StandardOpenOption.TRUNCATE_EXISTING,
                StandardOpenOption.WRITE);
    ByteBuffer buffer = ByteBuffer.allocate(6);
    buffer.putShort((short)KRB5_RV_VNO);
    buffer.order(ByteOrder.nativeOrder());
    buffer.putInt(KerberosTime.getDefaultSkew());
    buffer.flip();
    newChan.write(buffer);
    return newChan;
}
 

import java.nio.channels.SeekableByteChannel; //導入方法依賴的package包/類
public static void main(String[] args) throws Exception {

        AuthTimeWithHash a1 = new AuthTimeWithHash(client, server, time(0), 0,
                "1111111111111111");
        AuthTimeWithHash a2 = new AuthTimeWithHash(client, server, time(0), 0,
                "2222222222222222");
        KerberosTime now = new KerberosTime(time(0)*1000L);

        // When all new styles, must exact match
        ReplayCache cache = ReplayCache.getInstance("dfl:./c1");
        cache.checkAndStore(now, a1);
        cache.checkAndStore(now, a2);

        // When only old style in cache, partial match
        cache = ReplayCache.getInstance("dfl:./c2");
        cache.checkAndStore(now, a1);
        // A small surgery to remove the new style from the cache file
        SeekableByteChannel ch = Files.newByteChannel(Paths.get("c2"),
                StandardOpenOption.WRITE,
                StandardOpenOption.READ);
        ch.position(6);
        ch.write(ByteBuffer.wrap(a1.encode(false)));
        ch.truncate(ch.position());
        ch.close();
        try {
            cache.checkAndStore(now, a2);
            throw new Exception();
        } catch (KrbException ke) {
            // Correct
            System.out.println(ke);
        }
    }
 

import java.nio.channels.SeekableByteChannel; //導入方法依賴的package包/類
public static void main(String[] args) throws Exception {

        AuthTimeWithHash a1 = new AuthTimeWithHash(client, server, time(0), 0,
                "HASH", "1111111111111111");
        AuthTimeWithHash a2 = new AuthTimeWithHash(client, server, time(0), 0,
                "HASH", "2222222222222222");
        KerberosTime now = new KerberosTime(time(0)*1000L);

        // When all new styles, must exact match
        ReplayCache cache = ReplayCache.getInstance("dfl:./c1");
        cache.checkAndStore(now, a1);
        cache.checkAndStore(now, a2);

        // When only old style in cache, partial match
        cache = ReplayCache.getInstance("dfl:./c2");
        cache.checkAndStore(now, a1);
        // A small surgery to remove the new style from the cache file
        SeekableByteChannel ch = Files.newByteChannel(Paths.get("c2"),
                StandardOpenOption.WRITE,
                StandardOpenOption.READ);
        ch.position(6);
        ch.write(ByteBuffer.wrap(a1.encode(false)));
        ch.truncate(ch.position());
        ch.close();
        try {
            cache.checkAndStore(now, a2);
            throw new Exception();
        } catch (KrbException ke) {
            // Correct
            System.out.println(ke);
        }
    }
 

import java.nio.channels.SeekableByteChannel; //導入方法依賴的package包/類
@Test
public void fileCreatedAfterStartIsReadAfterPermissionsFixed() throws Exception {
    final File file = temporaryFolder.newFile();
    final Path path = file.toPath();
    // make sure the file doesn't exist prior to this test
    Files.deleteIfExists(path);

    final FileInput mockInput = mockFileInput();

    final CollectingBuffer buffer = new CollectingBuffer();
    final MessageBuilder messageBuilder = new MessageBuilder().input("input-id").outputs(new HashSet<String>()).source("test");
    final FileReaderService readerService = new FileReaderService(
            new SinglePathSet(path.toString()),
            Charsets.UTF_8,
            FileInput.InitialReadPosition.START,
            mockInput,
            messageBuilder,
            new NewlineChunkSplitter(),
            buffer,
            1024,
            250L,
            fileObserver);

    readerService.startAsync();
    readerService.awaitRunning();

    // create new unreadable file and write a line to it
    final SeekableByteChannel channel = Files.newByteChannel(file.toPath(),
            Sets.newHashSet(StandardOpenOption.CREATE_NEW, StandardOpenOption.APPEND),
            PosixFilePermissions.asFileAttribute(PosixFilePermissions.fromString("---------")));
    channel.write(ByteBuffer.wrap("hellotest\n".getBytes()));

    // Check that there has been no message read from the file.
    final Message msgNull = buffer.getMessageQueue().poll(500, TimeUnit.MILLISECONDS);
    assertNull("There should be no message read from the file!", msgNull);

    // Make file readable.
    Files.setPosixFilePermissions(file.toPath(), Sets.newHashSet(PosixFilePermission.OWNER_READ));

    // the reader service should detect the file modifcation event, create a chunkreader for it and eventually
    // a message should appear in the buffer
    // let's wait for that
    final Message msg = buffer.getMessageQueue().poll(10, TimeUnit.SECONDS);
    assertNotNull("file reader should have created a message", msg);
    assertEquals("message content matches", "hellotest", msg.getMessage());
    assertEquals("no more messages have been added to the buffer", 0, buffer.getMessageQueue().size());

    readerService.stopAsync();
    readerService.awaitTerminated();
}