byte,int,char,double的相互转换(java)
//整数到字节数组的转换public static byte[] intToByte(int number) {
int temp = number;
byte[] b=new byte;
for (int i=b.length-1;i>-1;i--){
b = new Integer(temp&0xff).byteValue(); //将最高位保存在最低位
temp = temp >> 8; //向右移8位
}
return b;
}
//字节数组到整数的转换
public static int byteToInt(byte[] b) {
int s = 0;
for (int i = 0; i < 3; i++) {
if (b >= 0)
s = s + b;
else
s = s + 256 + b;
s = s * 256;
}
if (b >= 0) //最后一个之所以不乘，是因为可能会溢出
s = s + b;
else
s = s + 256 + b;
return s;
}
//字符到字节转换
public static byte[] charToByte(char ch){
int temp=(int)ch;
byte[] b=new byte;
for (int i=b.length-1;i>-1;i--){
b = new Integer(temp&0xff).byteValue(); //将最高位保存在最低位
temp = temp >> 8; //向右移8位
}
return b;
}
//字节到字符转换
public static char byteToChar(byte[] b){
int s=0;
if(b>0)
s+=b;
else
s+=256+b;
s*=256;
if(b>0)
s+=b;
else
s+=256+b;
char ch=(char)s;
return ch;
}
//浮点到字节转换
public static byte[] doubleToByte(double d){
byte[] b=new byte;
long l=Double.doubleToLongBits(d);
for(int i=0;i<b.length;i++){
b=new Long(l).byteValue();
l=l>>8;
}
return b;
}
//字节到浮点转换
public static double byteToDouble(byte[] b){
long l;
l=b;
l&=0xff;
l|=((long)b<<8);
l&=0xffff;
l|=((long)b<<16);
l&=0xffffff;
l|=((long)b<<24);
l&=0xffffffffl;
l|=((long)b<<32);
l&=0xffffffffffl;
l|=((long)b<<40);
l&=0xffffffffffffl;
l|=((long)b<<48);
l|=((long)b<<56);
return Double.longBitsToDouble(l);
}
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