Concatenates one or more byte buffers to one large buffer. - Java java.nio

Java examples for java.nio:ByteBuffer

  1. HOME
  2. Java
  3. java.nio
  4. ByteBuffer

Description

Concatenates one or more byte buffers to one large buffer.

Demo Code


//package com.java2s;

import java.nio.ByteBuffer;

import java.util.Arrays;
import java.util.List;

public class Main {
    public static void main(String[] argv) throws Exception {
        List bbs = java.util.Arrays.asList("asdf", "java2s.com");
        System.out.println(concat(bbs));
    }//  w  w  w. jav  a 2  s  . c  o m

    public static final ByteBuffer EMPTY = ByteBuffer.allocate(0);

    /**
     * Concatenates one or more byte buffers to one large buffer. The combined
     * size of all buffers must not exceed {@link java.lang.Integer#MAX_VALUE}.
     * 
     * @param bbs list of byte buffers to combine
     * @return byte buffer containing the combined content of the supplied byte
     *         buffers
     */
    public static ByteBuffer concat(List<ByteBuffer> bbs) {
        long length = 0;

        // get amount of remaining bytes from all buffers
        for (ByteBuffer bb : bbs) {
            bb.rewind();
            length += bb.remaining();
        }

        if (length > Integer.MAX_VALUE) {
            throw new IllegalArgumentException(
                    "Buffers are too large for concatenation");
        }

        if (length == 0) {
            // very funny
            return EMPTY;
        }

        ByteBuffer bbNew = ByteBuffer.allocateDirect((int) length);

        // put all buffers from list
        for (ByteBuffer bb : bbs) {
            bb.rewind();
            bbNew.put(bb);
        }

        bbNew.rewind();

        return bbNew;
    }

    /**
     * Concatenates one or more byte buffers to one large buffer. The combined
     * size of all buffers must not exceed {@link java.lang.Integer#MAX_VALUE}.
     * 
     * @param bb one or more byte buffers to combine
     * @return byte buffer containing the combined content of the supplied byte
     *         buffers
     */
    public static ByteBuffer concat(ByteBuffer... bb) {
        return concat(Arrays.asList(bb));
    }
}

Related Tutorials