Java 十进制转二、八、十六进制的字符串

classDecToBin

{

 publicstaticvoidmain(String[] args)

 {

 //System.out.println("Hello World!");

 longdec = -9223372036854775807l;

 // -9223372036854775808 这个数不行，不要试，嘿嘿

 String binStr="";

 longdecAbs=Math.abs(dec);

 while(decAbs>0)

 { binStr=(decAbs&1)+binStr;

 decAbs>>=1;

 }

 binStr= dec<0?"-"+binStr:dec==0?"0":binStr;

 System.out.println(binStr);

 }

}

classDecToOct

{

 publicstaticvoidmain(String[] args)

 {

 //System.out.println("Hello World!");

 longdec=-0;//有-0 吗？

 String octStr="";

 longdecAbs=Math.abs(dec);

 while(decAbs>0)

 { octStr=(decAbs&7)+octStr;//

 decAbs>>=3;

 }

 octStr= dec<0?"-"+octStr:dec==0?"0":octStr;

 System.out.println(octStr);

 }

}

classDecToHex

{

 publicstaticvoidmain(String[] args)

 {

 System.out.println("Hello World!");

 longdec=-1;//计算器的负数不会弄 -。-

 String hexStr="";

 longdecAbs=Math.abs(dec);

 while(decAbs>0)

 {longlastFour=decAbs&15;

 if(lastFour>9)

 hexStr=(char)('A'+lastFour-10)+hexStr;

 elsehexStr=lastFour+hexStr;

 decAbs>>=4;

 }

 hexStr= dec<0?"-"+hexStr:dec==0?"0":hexStr;

 System.out.println(hexStr);

 }

}