Java : BufferedInputStream with Examples

final var file = Path.of("R:", "java-work", "aaa.data");
System.out.println(file); // R:\java-work\aaa.data

Files.write(file, new byte[]{10, 20, 30});

try (final var is = new BufferedInputStream(Files.newInputStream(file))) {
    System.out.println(is.read()); // 10
    System.out.println(is.read()); // 20
    System.out.println(is.read()); // 30
    System.out.println(is.read()); // -1
}

protected byte[] buf

The internal buffer array where the data is stored.

protected. I think it's rare to create a subclass of this class. Therefore, the code example is omitted.

protected int count

The index one greater than the index of the last valid byte in the buffer.

protected. I think it's rare to create a subclass of this class. Therefore, the code example is omitted.

protected int marklimit

The maximum read ahead allowed after a call to the mark method before subsequent calls to the reset method fail.

protected. I think it's rare to create a subclass of this class. Therefore, the code example is omitted.

protected int markpos

The value of the pos field at the time the last mark method was called.

protected. I think it's rare to create a subclass of this class. Therefore, the code example is omitted.

protected int pos

The current position in the buffer.

protected. I think it's rare to create a subclass of this class. Therefore, the code example is omitted.

in

Please see the link below.

• FilterInputStream with Examples

BufferedInputStream (InputStream in)

Creates a BufferedInputStream and saves its argument, the input stream in, for later use.

final byte[] buf = {10, 20, 30};
try (final var is = new BufferedInputStream(new ByteArrayInputStream(buf))) {
    System.out.println(is.read()); // 10
    System.out.println(is.read()); // 20
    System.out.println(is.read()); // 30
    System.out.println(is.read()); // -1
}

BufferedInputStream (InputStream in, int size)

Creates a BufferedInputStream with the specified buffer size, and saves its argument, the input stream in, for later use.

Please see also : BufferedInputStream(InputStream in)

class MyInputStream extends BufferedInputStream {
    MyInputStream(InputStream in) {
        super(in);
    }

    MyInputStream(InputStream in, int size) {
        super(in, size);
    }

    int getBufferSize() {
        return buf.length;
    }
}

final byte[] buf = {10, 20, 30};
try (final var is = new MyInputStream(new ByteArrayInputStream(buf))) {
    System.out.println(is.getBufferSize()); // 8192
}

try (final var is = new MyInputStream(new ByteArrayInputStream(buf), 32)) {
    System.out.println(is.getBufferSize()); // 32
}

int available ()

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream.

final byte[] buf = {10, 20, 30};
try (final var is = new BufferedInputStream(new ByteArrayInputStream(buf))) {
    System.out.println(is.available()); // 3
    System.out.println(is.read()); // 10

    System.out.println(is.available()); // 2
    System.out.println(is.read()); // 20

    System.out.println(is.available()); // 1
    System.out.println(is.read()); // 30

    System.out.println(is.available()); // 0
    System.out.println(is.read()); // -1
}

void close ()

Closes this input stream and releases any system resources associated with the stream.

final var file = Path.of("R:", "java-work", "aaa.data");
Files.write(file, new byte[]{10, 20, 30});

try (final var is = new BufferedInputStream(Files.newInputStream(file))) {
    final var ret = is.readAllBytes();
    System.out.println(Arrays.toString(ret)); // [10, 20, 30]
}

// An example without a try-with-resources statement.
final var file = Path.of("R:", "java-work", "aaa.data");
Files.write(file, new byte[]{10, 20, 30});

final var is = new BufferedInputStream(Files.newInputStream(file));
try {
    final var ret = is.readAllBytes();
    System.out.println(Arrays.toString(ret)); // [10, 20, 30]
} finally {
    is.close();
}

void mark (int readlimit)

See the general contract of the mark method of InputStream.

final byte[] buf = {10, 20, 30, 40, 50};

try (final var is = new BufferedInputStream(new ByteArrayInputStream(buf))) {
    System.out.println(is.read()); // 10
    System.out.println(is.read()); // 20

    is.mark(4);

    System.out.println(is.read()); // 30
    System.out.println(is.read()); // 40
    System.out.println(is.read()); // 50
    System.out.println(is.read()); // -1

    is.reset();

    System.out.println(is.read()); // 30
    System.out.println(is.read()); // 40
    System.out.println(is.read()); // 50
    System.out.println(is.read()); // -1
}

boolean markSupported ()

Tests if this input stream supports the mark and reset methods.

final byte[] buf = {10, 20, 30};

try (final var is = new BufferedInputStream(new ByteArrayInputStream(buf))) {
    System.out.println(is.markSupported()); // true
}

int read ()

See the general contract of the read method of InputStream.

final byte[] buf = {10, 20, 30};
try (final var is = new BufferedInputStream(new ByteArrayInputStream(buf))) {
    System.out.println(is.read()); // 10
    System.out.println(is.read()); // 20
    System.out.println(is.read()); // 30
    System.out.println(is.read()); // -1
}

int read (byte[] b, int off, int len)

Reads bytes from this byte-input stream into the specified byte array, starting at the given offset.

final byte[] buf = {10, 20, 30};

try (final var is = new BufferedInputStream(new ByteArrayInputStream(buf))) {
    final var b1 = new byte[3];

    System.out.println(is.read(b1, 0, 1)); // 1
    System.out.println(Arrays.toString(b1)); // [10, 0, 0]

    final var b2 = new byte[3];

    System.out.println(is.read(b2, 0, 2)); // 2
    System.out.println(Arrays.toString(b2)); // [20, 30, 0]

    final var b3 = new byte[3];

    System.out.println(is.read(b3, 0, 3)); // -1
    System.out.println(Arrays.toString(b3)); // [0, 0, 0]
}

try (final var is = new BufferedInputStream(new ByteArrayInputStream(buf))) {
    final var b1 = new byte[3];

    System.out.println(is.read(b1, 2, 1)); // 1
    System.out.println(Arrays.toString(b1)); // [0, 0, 10]

    final var b2 = new byte[3];

    System.out.println(is.read(b2, 1, 2)); // 2
    System.out.println(Arrays.toString(b2)); // [0, 20, 30]

    final var b3 = new byte[3];

    System.out.println(is.read(b3, 0, 3)); // -1
    System.out.println(Arrays.toString(b3)); // [0, 0, 0]
}

void reset ()

See the general contract of the reset method of InputStream.

final byte[] buf = {10, 20, 30, 40, 50};

try (final var is = new BufferedInputStream(new ByteArrayInputStream(buf))) {
    System.out.println(is.read()); // 10
    System.out.println(is.read()); // 20

    is.mark(4);

    System.out.println(is.read()); // 30
    System.out.println(is.read()); // 40
    System.out.println(is.read()); // 50
    System.out.println(is.read()); // -1

    is.reset();

    System.out.println(is.read()); // 30
    System.out.println(is.read()); // 40
    System.out.println(is.read()); // 50
    System.out.println(is.read()); // -1
}

long skip (long n)

See the general contract of the skip method of InputStream.

final byte[] buf = {10, 20, 30, 40, 50, 60, 70, 80, 90, 100};

try (final var is = new BufferedInputStream(new ByteArrayInputStream(buf))) {
    System.out.println(is.read()); // 10

    System.out.println(is.skip(1)); // 1
    System.out.println(is.read()); // 30

    System.out.println(is.skip(2)); // 2
    System.out.println(is.read()); // 60

    System.out.println(is.skip(3)); // 3
    System.out.println(is.read()); // 100

    System.out.println(is.skip(1)); // 0
    System.out.println(is.read()); // -1
}

read

Please see the link below.

• FilterInputStream with Examples

nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Please see the link below.

• InputStream with Examples