Java ByteBuffer Put readBytes(InputStream is, ByteBuffer buffer)

Description

Reads as many bytes from the input stream into the given ByteBuffer, starting at current buffer position and ending at the current buffer's limit.

License

Open Source License

Declaration

public static void readBytes(InputStream is, ByteBuffer buffer) throws IOException 

Method Source Code

//package com.java2s;
// See LICENSE.txt for license information

import java.io.IOException;
import java.io.InputStream;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;

public class Main {
    /**/*from   w ww. j  a  va 2  s . c  o  m*/
     * Reads "length" number of bytes from the specified input stream and returns them
     * as new {@link ByteBuffer} object.
     */
    public static ByteBuffer readBytes(InputStream is, int length) throws IOException {
        ByteBuffer bb = null;
        if (length > 0) {
            bb = getByteBuffer(length);
            readBytes(is, bb);
        } else {
            bb = getByteBuffer(0);
        }
        bb.position(0);
        return bb;
    }

    /**
     * Reads as many bytes from the input stream into the given ByteBuffer, starting at current
     * buffer position and ending at the current buffer's limit.
     */
    public static void readBytes(InputStream is, ByteBuffer buffer) throws IOException {
        byte[] buf = new byte[8192];
        while (buffer.remaining() > 0) {
            int len = Math.min(buf.length, buffer.remaining());
            int n = is.read(buf, 0, len);
            if (n < 0) {
                break;
            }
            buffer.put(buf, 0, n);
        }
    }

    /** Reads as many bytes from the input stream into the specified byte array. */
    public static void readBytes(InputStream is, byte[] buffer) throws IOException {
        readBytes(is, buffer, 0, buffer.length);
    }

    /**
     * Reads up to "length" bytes of data from the input stream into the given byte array,
     * starting at the specified offset.
     */
    public static void readBytes(InputStream is, byte[] buffer, int offset, int length) throws IOException {
        int bytesRead = 0;
        offset = Math.max(0, Math.min(offset, length));
        length = Math.min(buffer.length - offset, length);
        while (bytesRead < length) {
            int newRead = is.read(buffer, offset + bytesRead, length - bytesRead);
            if (newRead == -1) {
                throw new IOException("Unable to read remaining " + (buffer.length - bytesRead) + " bytes");
            }
            bytesRead += newRead;
        }
    }

    /** Returns a fully initialized empty {@link ByteBuffer} in little endian order. */
    public static ByteBuffer getByteBuffer(int size) {
        return ByteBuffer.allocate(Math.max(0, size)).order(ByteOrder.LITTLE_ENDIAN);
    }

    /** Returns a {@link ByteBuffer} based on {@code buffer} in little endian order. */
    public static ByteBuffer getByteBuffer(byte[] buffer) {
        if (buffer == null) {
            buffer = new byte[0];
        }
        return ByteBuffer.wrap(buffer).order(ByteOrder.LITTLE_ENDIAN);
    }
}

Related

1. read(InputStream is, ByteBuffer buf, int bytes)
2. readAsByteBuffer(final InputStream source)
3. readBER32(ByteBuffer input)
4. readByteBuffer(DataInputStream is)
5. readByteBufferList(DataInputStream is)
6. readByteVector8(ByteBuffer input)
7. readFully(InputStream in, ByteBuffer out)
8. readFully(InputStream is, ByteBuffer buf)
9. readFully(InputStream is, ByteBuffer buffer, int nrBytes)