Java ByteBuffer.allocate方法代码示例

import java.nio.ByteBuffer; //导入方法依赖的package包/类
@Override
public void xor_A_with_B ( AT_Machine_State state ) {
	ByteBuffer a = ByteBuffer.allocate(32);
	a.order( ByteOrder.LITTLE_ENDIAN );
	a.put(state.get_A1());
	a.put(state.get_A2());
	a.put(state.get_A3());
	a.put(state.get_A4());
	a.clear();
	
	ByteBuffer b = ByteBuffer.allocate(32);
	b.order( ByteOrder.LITTLE_ENDIAN );
	b.put(state.get_B1());
	b.put(state.get_B2());
	b.put(state.get_B3());
	b.put(state.get_B4());
	b.clear();
	
	state.set_A1(AT_API_Helper.getByteArray(a.getLong(0) ^ b.getLong(0)));
	state.set_A2(AT_API_Helper.getByteArray(a.getLong(8) ^ b.getLong(8)));
	state.set_A3(AT_API_Helper.getByteArray(a.getLong(16) ^ b.getLong(16)));
	state.set_A4(AT_API_Helper.getByteArray(a.getLong(24) ^ b.getLong(24)));
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
@Test
public void testRegion() {
  ByteBuffer byteBuffer = ByteBuffer.allocate(10);
  byteBuffer.limit(7);
  Buffer buff = Buffer.wrap(byteBuffer); //assuming buff has cap of 8
  assertEquals(buff.getCapacity(), 10); //wrong should be 8
  buff.getByte(); //pos moves to 1
  Buffer copyBuff = buff.region(); //pos: 0, start: 0, end: 6: cap: 7
  assertEquals(copyBuff.getEnd(), 6);
  assertEquals(copyBuff.getCapacity(), 6);
  assertEquals(copyBuff.getStart(), 0);
  assertEquals(copyBuff.getPosition(), 0);

  buff.setStartPositionEnd(1, 1, 5);
  buff.getByte();
  Buffer copyBuff2 = buff.region();
  assertEquals(copyBuff2.getEnd(), 3);
  assertEquals(copyBuff2.getCapacity(), 3);
  assertEquals(copyBuff2.getStart(), 0);
  assertEquals(copyBuff2.getPosition(), 0);
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * Returns an integer value out of a byte array. 
 * 
 * @param byteArray The byte array to be converted into its decimal representation
 * @return The integer value representing the byte array
 */
public static int toIntFromByteArray(byte[] byteArray) {
	// Allocating a byte buffer holding 4 bytes for the int value
	ByteBuffer bb = ByteBuffer.allocate(4);
	
	/*
	 * The given byte array might hold less than 4 bytes, e.g. the SECC port of the SECC Discovery
	 * Response only holds 2 bytes. Thus, we must account for this and guarantee the Big Endian 
	 * byte order.
	 */
	bb.position(4 - byteArray.length);
	bb.put(byteArray);
	
	// Setting the current position to 0, otherwise getInt() would throw a BufferUnderflowException
	bb.position(0);
	
	return bb.getInt();
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
private static ByteBuffer createMockPacket() {
    ByteBuffer buffer = ByteBuffer.allocate(32);

    buffer.put((byte) ((4 << 4) | 5)); // versionAndIHL
    buffer.put((byte) 0); // ToS
    buffer.putShort((short) 32); // total length 20 + 8 + 4
    buffer.putInt(0); // IdFlagsFragmentOffset
    buffer.put((byte) 0); // TTL
    buffer.put((byte) 17); // protocol (UDP)
    buffer.putShort((short) 0); // checksum
    buffer.putInt(0x12345678); // source address
    buffer.putInt(0x42424242); // destination address

    buffer.putShort((short) 1234); // source port
    buffer.putShort((short) 5678); // destination port
    buffer.putShort((short) 4); // length
    buffer.putShort((short) 0); // checksum

    buffer.putInt(0x11223344); // payload

    return buffer;
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
ByteBufferReference combine(ByteBufferReference ref1, ByteBufferReference ref2) {
    ByteBuffer buf1 = ref1.get();
    ByteBuffer buf2 = ref2.get();
    int avail1 = buf1.capacity() - buf1.remaining();
    if (buf2.remaining() < avail1) {
        buf1.compact();
        buf1.put(buf2);
        buf1.flip();
        ref2.clear();
        return ref1;
    }
    int newsize = buf1.remaining() + buf2.remaining();
    ByteBuffer newbuf = ByteBuffer.allocate(newsize); // getting rid of buffer pools
    newbuf.put(buf1);
    newbuf.put(buf2);
    newbuf.flip();
    ref1.clear();
    ref2.clear();
    return ByteBufferReference.of(newbuf);
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
public static ByteBuffer allocateByteBuffer(boolean useDirectBuffer,
                                            int bufSize) {
  if (useDirectBuffer) {
    return ByteBuffer.allocateDirect(bufSize);
  } else {
    return ByteBuffer.allocate(bufSize);
  }
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
private void append(FileRecords fileRecords, byte[][] values) throws IOException {
    long offset = 0L;
    for (byte[] value : values) {
        ByteBuffer buffer = ByteBuffer.allocate(128);
        MemoryRecordsBuilder builder = MemoryRecords.builder(buffer, RecordBatch.CURRENT_MAGIC_VALUE,
                CompressionType.NONE, TimestampType.CREATE_TIME, offset);
        builder.appendWithOffset(offset++, System.currentTimeMillis(), null, value);
        fileRecords.append(builder.build());
    }
    fileRecords.flush();
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * Calculated checksum for given data.
 *
 * @param content of file.
 * @return CRC32 checksum.
 */
public static byte[] calculateChecksum(byte[] content) {
    CRC32 crc = new CRC32();
    crc.update(content);
    ByteBuffer buffer = ByteBuffer.allocate(Long.SIZE / Byte.SIZE);
    return buffer.putLong(crc.getValue()).array();
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * Test the decoding of a ModifyDNResponse with no LdapResult
 */
@Test
public void testDecodeModifyDNResponseEmptyResult()
{
    Asn1Decoder ldapDecoder = new Asn1Decoder();

    ByteBuffer stream = ByteBuffer.allocate( 0x07 );

    stream.put( new byte[]
        { 0x30, 0x05, // LDAPMessage ::=SEQUENCE {
            0x02,
            0x01,
            0x01, // messageID MessageID
            0x6D,
            0x00 // CHOICE { ..., modifyDNResponse ModifyDNResponse,
        // ...
    } );

    stream.flip();

    // Allocate a LdapMessage Container
    LdapMessageContainer<ModifyDnResponseDecorator> ldapMessageContainer =
        new LdapMessageContainer<ModifyDnResponseDecorator>( codec );

    // Decode a ModifyDNResponse message
    try
    {
        ldapDecoder.decode( stream, ldapMessageContainer );
    }
    catch ( DecoderException de )
    {
        assertTrue( true );
        return;
    }

    fail( "We should not reach this point" );
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/** write the catalog as a UTF-8 byte string via connection */
@Override
public void loadCatalog(final String serializedCatalog) throws EEException {
    int result = ExecutionEngine.ERRORCODE_ERROR;
    m_data.clear();

    try {
        final byte catalogBytes[] = serializedCatalog.getBytes("UTF-8");
        if (m_data.capacity() < catalogBytes.length + 100) {
            m_data = ByteBuffer.allocate(catalogBytes.length + 100);
        }
        m_data.putInt(Commands.LoadCatalog.m_id);
        m_data.put(catalogBytes);
        m_data.put((byte)'\0');
    } catch (final UnsupportedEncodingException ex) {
        Logger.getLogger(ExecutionEngineIPC.class.getName()).log(
                Level.SEVERE, null, ex);
    }

    try {
        m_data.flip();
        m_connection.write();
        result = m_connection.readStatusByte();
    } catch (final IOException e) {
        System.out.println("Exception: " + e.getMessage());
        throw new RuntimeException(e);
    }
    checkErrorCode(result);
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
@Test
public void testEquivalence() {
  ByteBuffer bb = ByteBuffer.allocate(1);
  this.reservoir.putBuffer(bb);
  this.reservoir.putBuffer(bb);
  this.reservoir.putBuffer(bb);
  assertEquals(3, this.reservoir.buffers.size());
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
public byte[] getFullBytes() {
    ByteBuffer buffer = ByteBuffer.allocate(ADDITIONAL_SECTION_SIZE);
    buffer.order(ByteOrder.LITTLE_ENDIAN);
    buffer.put(md5Hash);
    buffer.put(padding);
    buffer.putInt(getSecondaryAdler32());
    return buffer.array();
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * Convert to a byte array. Note that the numbers are stored in big-endian
 * order.
 *
 * @return the byte array
 */
public byte[] toByteArray() {
	ByteBuffer buffer = ByteBuffer.allocate(12);
	putToByteBuffer(buffer);
	return buffer.array(); // using .allocate ensures there is a backing
							// array that can be returned
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
@Override
public ByteBuffer get() {
    ByteBuffer content = ByteBuffer.allocate(1);
    content.put((byte) (levelIndependentlyDecodable ? 0x80 : 0x00));
    content.rewind();
    return content;
}
 

import java.nio.ByteBuffer; //导入方法依赖的package包/类
/**
 * Returns <code>n</code> random bytes
 *
 * @param n number of bytes to return
 * @return the next <code>n</code> random bytes
 */
byte[] nextBytes(int n)
{
    ByteBuffer buf = ByteBuffer.allocate(n);

    while (buf.hasRemaining())
    {
        ByteBuffer cbuf = ByteBuffer.allocate(seed.length + 4);
        cbuf.put(seed);
        cbuf.putInt(counter);
        byte[] array = cbuf.array();
        byte[] hash = new byte[hashAlg.getDigestSize()];

        hashAlg.update(array, 0, array.length);

        hashAlg.doFinal(hash, 0);

        if (buf.remaining() < hash.length)
        {
            buf.put(hash, 0, buf.remaining());
        }
        else
        {
            buf.put(hash);
        }
        counter++;
    }

    return buf.array();
}