java二进制,字节数组,字符,十六进制,BCD编码转换

1. //整数到字节数组转换
2. publicstaticbyte[]int2bytes(intn){
3. byte[]ab=newbyte[4];
4. ab[0]=(byte)(0xff&n);
5. ab[1]=(byte)((0xff00&n)>>8);
6. ab[2]=(byte)((0xff0000&n)>>16);
7. ab[3]=(byte)((0xff000000&n)>>24);
8. returnab;
9. }
11. //字节数组到整数的转换
12. publicstaticintbytes2int(byteb[]){
13. ints=0;
14. s=((((b[0]&0xff)<<8|(b[1]&0xff))<<8)|(b[2]&0xff))<<8
15. |(b[3]&0xff);
16. returns;
17. }
19. //字节转换到字符
20. publicstaticcharbyte2char(byteb){
21. return(char)b;
22. }
24. privatefinalstaticbyte[]hex="0123456789ABCDEF".getBytes();
26. privatestaticintparse(charc){
27. if(c>='a')
28. return(c-'a'+10)&0x0f;
29. if(c>='A')
30. return(c-'A'+10)&0x0f;
31. return(c-'0')&0x0f;
32. }
34. //从字节数组到十六进制字符串转换
35. publicstaticStringBytes2HexString(byte[]b){
36. byte[]buff=newbyte[2*b.length];
37. for(inti=0;i<b.length;i++){
38. buff[2*i]=hex[(b[i]>>4)&0x0f];
39. buff[2*i+1]=hex[b[i]&0x0f];
40. }
41. returnnewString(buff);
42. }
44. //从十六进制字符串到字节数组转换
45. publicstaticbyte[]HexString2Bytes(Stringhexstr){
46. byte[]b=newbyte[hexstr.length()/2];
47. intj=0;
48. for(inti=0;i<b.length;i++){
49. charc0=hexstr.charAt(j++);
50. charc1=hexstr.charAt(j++);
51. b[i]=(byte)((parse(c0)<<4)|parse(c1));
52. }
53. returnb;
54. }