Java基本类型与byte数组之间相互转换
package cn.teaey.utils;
import java.nio.charset.Charset;
public class ByteUtil
{
public static byte[]
getBytes(short data)
{
byte[]
bytes = new byte[2];
bytes[0] = (byte)
(data & 0xff);
bytes[1] = (byte)
((data & 0xff00) >> 8);
return bytes;
}
public static byte[]
getBytes(char data)
{
byte[]
bytes = new byte[2];
bytes[0] = (byte)
(data);
bytes[1] = (byte)
(data >> 8);
return bytes;
}
public static byte[]
getBytes(int data)
{
byte[]
bytes = new byte[4];
bytes[0] = (byte)
(data & 0xff);
bytes[1] = (byte)
((data & 0xff00) >> 8);
bytes[2] = (byte)
((data & 0xff0000) >> 16);
bytes[3] = (byte)
((data & 0xff000000) >> 24);
return bytes;
}
public static byte[]
getBytes(long data)
{
byte[]
bytes = new byte[8];
bytes[0] = (byte)
(data & 0xff);
bytes[1] = (byte)
((data >> 8) & 0xff);
bytes[2] = (byte)
((data >> 16) & 0xff);
bytes[3] = (byte)
((data >> 24) & 0xff);
bytes[4] = (byte)
((data >> 32) & 0xff);
bytes[5] = (byte)
((data >> 40) & 0xff);
bytes[6] = (byte)
((data >> 48) & 0xff);
bytes[7] = (byte)
((data >> 56) & 0xff);
return bytes;
}
public static byte[]
getBytes(float data)
{
int intBits
= Float.floatToIntBits(data);
return getBytes(intBits);
}
public static byte[]
getBytes(double data)
{
long intBits
= Double.doubleToLongBits(data);
return getBytes(intBits);
}
public static byte[]
getBytes(String data, String charsetName)
{
Charset charset = Charset.forName(charsetName);
return data.getBytes(charset);
}
public static byte[]
getBytes(String data)
{
return getBytes(data, "GBK");
}
public static short getShort(byte[]
bytes)
{
return (short)
((0xff & bytes[0]) | (0xff00 & (bytes[1] << 8)));
}
public static char getChar(byte[]
bytes)
{
return (char)
((0xff & bytes[0]) | (0xff00 & (bytes[1] << 8)));
}
public static int getInt(byte[]
bytes)
{
return (0xff
& bytes[0]) | (0xff00 & (bytes[1] << 8)) | (0xff0000 & (bytes[2] << 16)) | (0xff000000 & (bytes[3] << 24));
}
public static long getLong(byte[]
bytes)
{
return(0xffL
& (long)bytes[0])
| (0xff00L & ((long)bytes[1]
<< 8)) | (0xff0000L & ((long)bytes[2]
<< 16)) | (0xff000000L & ((long)bytes[3]
<< 24))
| (0xff00000000L
& ((long)bytes[4]
<< 32)) | (0xff0000000000L & ((long)bytes[5]
<< 40)) | (0xff000000000000L & ((long)bytes[6]
<< 48)) | (0xff00000000000000L & ((long)bytes[7]
<< 56));
}
public static float getFloat(byte[]
bytes)
{
return Float.intBitsToFloat(getInt(bytes));
}
public static double getDouble(byte[]
bytes)
{
long l
= getLong(bytes);
System.out.println(l);
return Double.longBitsToDouble(l);
}
public static String
getString(byte[]
bytes, String charsetName)
{
return new String(bytes,
Charset.forName(charsetName));
}
public static String
getString(byte[]
bytes)
{
return getString(bytes, "GBK");
}
public static void main(String[]
args)
{
short s
= 122;
int i
= 122;
long l
= 1222222;
char c
= 'a';
float f
= 122.22f;
double d
= 122.22;
String string = "我是好孩子";
System.out.println(s);
System.out.println(i);
System.out.println(l);
System.out.println(c);
System.out.println(f);
System.out.println(d);
System.out.println(string);
System.out.println("**************");
System.out.println(getShort(getBytes(s)));
System.out.println(getInt(getBytes(i)));
System.out.println(getLong(getBytes(l)));
System.out.println(getChar(getBytes(c)));
System.out.println(getFloat(getBytes(f)));
System.out.println(getDouble(getBytes(d)));
System.out.println(getString(getBytes(string)));
}
}
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