자바는 unsigned primitive type을 지원하지 않습니다.
따라서, unsigned type을 사용할 수 있는 C/C++ 상호 호환을 위해서 Java쪽에서 unsigned type의 처리가 필요합니다. 아래의 코드는 http://www.javafaq.nu/java-example-code-342.html 에서 스크랩을 했습니다.
따라서, unsigned type을 사용할 수 있는 C/C++ 상호 호환을 위해서 Java쪽에서 unsigned type의 처리가 필요합니다. 아래의 코드는 http://www.javafaq.nu/java-example-code-342.html 에서 스크랩을 했습니다.
package com.ronsoft.books.nio.buffers;
import java.nio.ByteBuffer;
/**
* Utility class to get and put unsigned values to a ByteBuffer object.
* All methods here are static and take a ByteBuffer object argument.
* Since java does not provide unsigned primitive types, each unsigned
* value read from the buffer is promoted up to the next bigger primitive
* data type. getUnsignedByte() returns a short, getUnsignedShort() returns
* an int and getUnsignedInt() returns a long. There is no getUnsignedLong()
* since there is no primitive type to hold the value returned. If needed,
* methods returning BigInteger could be implemented.
* Likewise, the put methods take a value larger than the type they will
* be assigning. putUnsignedByte takes a short argument, etc.
*
* @author Ron Hitchens (ron@ronsoft.com)
* @version $Id: Unsigned.java,v 1.1 2002/02/12 22:06:44 ron Exp $
*/
public class Unsigned {
public static short getUnsignedByte (ByteBuffer bb){
return ((short)(bb.get() & 0xff));
}
public static void putUnsignedByte (ByteBuffer bb, int value){
bb.put ((byte)(value & 0xff));
}
public static short getUnsignedByte (ByteBuffer bb, int position){
return ((short)(bb.get (position) & (short)0xff));
}
public static void putUnsignedByte (ByteBuffer bb, int position,int value){
bb.put (position, (byte)(value & 0xff));
}
// ---------------------------------------------------------------
public static int getUnsignedShort (ByteBuffer bb){
return (bb.getShort() & 0xffff);
}
public static void putUnsignedShort (ByteBuffer bb, int value){
bb.putShort ((short)(value & 0xffff));
}
public static int getUnsignedShort (ByteBuffer bb, int position){
return (bb.getShort (position) & 0xffff);
}
public static void putUnsignedShort (ByteBuffer bb, int position, int value){
bb.putShort (position, (short)(value & 0xffff));
}
// ---------------------------------------------------------------
public static long getUnsignedInt (ByteBuffer bb){
return ((long)bb.getInt() & 0xffffffffL);
}
public static void putUnsignedInt (ByteBuffer bb, long value){
bb.putInt ((int)(value & 0xffffffffL));
}
public static long getUnsignedInt (ByteBuffer bb, int position){
return ((long)bb.getInt (position) & 0xffffffffL);
}
public static void putUnsignedInt (ByteBuffer bb, int position, long value){
bb.putInt (position, (int)(value & 0xffffffffL));
}
// ---------------------------------------------------
public static void main (String [] argv) throws Exception {
ByteBuffer buffer = ByteBuffer.allocate (20);
buffer.clear();
Unsigned.putUnsignedByte (buffer, 255);
Unsigned.putUnsignedByte (buffer, 128);
Unsigned.putUnsignedShort (buffer, 0xcafe);
Unsigned.putUnsignedInt (buffer, 0xcafebabe);
for (int i = 0; i < 8; i++) {
System.out.println ("" + i + ": "
+ Integer.toHexString ((int)getUnsignedByte (buffer, i)));
}
System.out.println ("2: " + Integer.toHexString (getUnsignedShort (buffer, 2)));
System.out.println ("4: " + Long.toHexString (getUnsignedInt (buffer, 4)));
}
}
import java.nio.ByteBuffer;
/**
* Utility class to get and put unsigned values to a ByteBuffer object.
* All methods here are static and take a ByteBuffer object argument.
* Since java does not provide unsigned primitive types, each unsigned
* value read from the buffer is promoted up to the next bigger primitive
* data type. getUnsignedByte() returns a short, getUnsignedShort() returns
* an int and getUnsignedInt() returns a long. There is no getUnsignedLong()
* since there is no primitive type to hold the value returned. If needed,
* methods returning BigInteger could be implemented.
* Likewise, the put methods take a value larger than the type they will
* be assigning. putUnsignedByte takes a short argument, etc.
*
* @author Ron Hitchens (ron@ronsoft.com)
* @version $Id: Unsigned.java,v 1.1 2002/02/12 22:06:44 ron Exp $
*/
public class Unsigned {
public static short getUnsignedByte (ByteBuffer bb){
return ((short)(bb.get() & 0xff));
}
public static void putUnsignedByte (ByteBuffer bb, int value){
bb.put ((byte)(value & 0xff));
}
public static short getUnsignedByte (ByteBuffer bb, int position){
return ((short)(bb.get (position) & (short)0xff));
}
public static void putUnsignedByte (ByteBuffer bb, int position,int value){
bb.put (position, (byte)(value & 0xff));
}
// ---------------------------------------------------------------
public static int getUnsignedShort (ByteBuffer bb){
return (bb.getShort() & 0xffff);
}
public static void putUnsignedShort (ByteBuffer bb, int value){
bb.putShort ((short)(value & 0xffff));
}
public static int getUnsignedShort (ByteBuffer bb, int position){
return (bb.getShort (position) & 0xffff);
}
public static void putUnsignedShort (ByteBuffer bb, int position, int value){
bb.putShort (position, (short)(value & 0xffff));
}
// ---------------------------------------------------------------
public static long getUnsignedInt (ByteBuffer bb){
return ((long)bb.getInt() & 0xffffffffL);
}
public static void putUnsignedInt (ByteBuffer bb, long value){
bb.putInt ((int)(value & 0xffffffffL));
}
public static long getUnsignedInt (ByteBuffer bb, int position){
return ((long)bb.getInt (position) & 0xffffffffL);
}
public static void putUnsignedInt (ByteBuffer bb, int position, long value){
bb.putInt (position, (int)(value & 0xffffffffL));
}
// ---------------------------------------------------
public static void main (String [] argv) throws Exception {
ByteBuffer buffer = ByteBuffer.allocate (20);
buffer.clear();
Unsigned.putUnsignedByte (buffer, 255);
Unsigned.putUnsignedByte (buffer, 128);
Unsigned.putUnsignedShort (buffer, 0xcafe);
Unsigned.putUnsignedInt (buffer, 0xcafebabe);
for (int i = 0; i < 8; i++) {
System.out.println ("" + i + ": "
+ Integer.toHexString ((int)getUnsignedByte (buffer, i)));
}
System.out.println ("2: " + Integer.toHexString (getUnsignedShort (buffer, 2)));
System.out.println ("4: " + Long.toHexString (getUnsignedInt (buffer, 4)));
}
}
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