Java 不同进制数转换

import java.io.ByteArrayInputStream;  
import java.io.ByteArrayOutputStream;  
import java.io.IOException;  
import java.io.ObjectInputStream;  
import java.io.ObjectOutputStream;  
import java.io.Serializable;  
import java.security.MessageDigest;  
import java.security.NoSuchAlgorithmException;  
  
public final class Converts {  
  
 public final static char[] BToA = "0123456789abcdef".toCharArray() ;  
 private Converts() {  
 }  
  
 /** 
  * 把16进制字符串转换成字节数组 
  * @param hex 
  * @return 
  */  
 public static byte[] hexStringToByte(String hex) {  
  int len = (hex.length() / 2);  
  byte[] result = new byte[len];  
  char[] achar = hex.toCharArray();  
  for (int i = 0; i < len; i++) {  
   int pos = i * 2;  
   result[i] = (byte) (toByte(achar[pos]) << 4 | toByte(achar[pos + 1]));  
  }  
  return result;  
 }  
  
 private static byte toByte(char c) {  
  byte b = (byte) "0123456789ABCDEF".indexOf(c);  
  return b;  
 }  
  
 /** 
  * 把字节数组转换成16进制字符串 
  * @param bArray 
  * @return 
  */  
 public static final String bytesToHexString(byte[] bArray) {  
  StringBuffer sb = new StringBuffer(bArray.length);  
  String sTemp;  
  for (int i = 0; i < bArray.length; i++) {  
   sTemp = Integer.toHexString(0xFF & bArray[i]);  
   if (sTemp.length() < 2)  
    sb.append(0);  
   sb.append(sTemp.toUpperCase());  
  }  
  return sb.toString();  
 }  
  
 /** 
  * 把字节数组转换为对象 
  * @param bytes 
  * @return 
  * @throws IOException 
  * @throws ClassNotFoundException 
  */  
 public static final Object bytesToObject(byte[] bytes) throws IOException, ClassNotFoundException {  
  ByteArrayInputStream in = new ByteArrayInputStream(bytes);  
  ObjectInputStream oi = new ObjectInputStream(in);  
  Object o = oi.readObject();  
  oi.close();  
  return o;  
 }  
  
 /** 
  * 把可序列化对象转换成字节数组 
  * @param s 
  * @return 
  * @throws IOException 
  */  
 public static final byte[] objectToBytes(Serializable s) throws IOException {  
  ByteArrayOutputStream out = new ByteArrayOutputStream();  
  ObjectOutputStream ot = new ObjectOutputStream(out);  
  ot.writeObject(s);  
  ot.flush();  
  ot.close();  
  return out.toByteArray();  
 }  
   
 public static final String objectToHexString(Serializable s) throws IOException{  
  return bytesToHexString(objectToBytes(s));  
 }  
   
 public static final Object hexStringToObject(String hex) throws IOException, ClassNotFoundException{  
  return bytesToObject(hexStringToByte(hex));  
 }  
   
 /** 
  * @函数功能: BCD码转为10进制串(阿拉伯数据) 
  * @输入参数: BCD码 
  * @输出结果: 10进制串 
  */  
 public static String bcd2Str(byte[] bytes){  
  StringBuffer temp=new StringBuffer(bytes.length*2);  
  
  for(int i=0;i>>4));  
   temp.append((byte)(bytes[i]& 0x0f));  
  }  
  return temp.toString().substring(0,1).equalsIgnoreCase("0")?temp.toString().substring(1):temp.toString();  
 }  
  
 /** 
  * @函数功能: 10进制串转为BCD码 
  * @输入参数: 10进制串 
  * @输出结果: BCD码 
  */  
 public static byte[] str2Bcd(String asc) {  
  int len = asc.length();  
  int mod = len % 2;  
  
  if (mod != 0) {  
   asc = "0" + asc;  
   len = asc.length();  
  }  
  
  byte abt[] = new byte[len];  
  if (len >= 2) {  
   len = len / 2;  
  }  
  
  byte bbt[] = new byte[len];  
  abt = asc.getBytes();  
  int j, k;  
  
  for (int p = 0; p < asc.length()/2; p++) {  
   if ( (abt[2 * p] >= '0') && (abt[2 * p] <= '9')) {  
    j = abt[2 * p] - '0';  
   } else if ( (abt[2 * p] >= 'a') && (abt[2 * p] <= 'z')) {  
    j = abt[2 * p] - 'a' + 0x0a;  
   } else {  
    j = abt[2 * p] - 'A' + 0x0a;  
   }  
  
   if ( (abt[2 * p + 1] >= '0') && (abt[2 * p + 1] <= '9')) {  
    k = abt[2 * p + 1] - '0';  
   } else if ( (abt[2 * p + 1] >= 'a') && (abt[2 * p + 1] <= 'z')) {  
    k = abt[2 * p + 1] - 'a' + 0x0a;  
   }else {  
    k = abt[2 * p + 1] - 'A' + 0x0a;  
   }  
  
   int a = (j << 4) + k;  
   byte b = (byte) a;  
   bbt[p] = b;  
  }  
  return bbt;  
 }  
   
 public static String BCD2ASC(byte[] bytes) {  
  StringBuffer temp = new StringBuffer(bytes.length * 2);  
  
  for (int i = 0; i < bytes.length; i++) {  
   int h = ((bytes[i] & 0xf0) >>> 4);  
   int l = (bytes[i] & 0x0f);     
   temp.append(BToA[h]).append( BToA[l]);  
  }  
  return temp.toString() ;  
 }  
   
 /** 
  * MD5加密字符串，返回加密后的16进制字符串 
  * @param origin 
  * @return 
  */  
 public static String MD5EncodeToHex(String origin) {   
     return bytesToHexString(MD5Encode(origin));  
   }  
   
 /** 
  * MD5加密字符串，返回加密后的字节数组 
  * @param origin 
  * @return 
  */  
 public static byte[] MD5Encode(String origin){  
  return MD5Encode(origin.getBytes());  
 }  
   
 /** 
  * MD5加密字节数组，返回加密后的字节数组 
  * @param bytes 
  * @return 
  */  
 public static byte[] MD5Encode(byte[] bytes){  
  MessageDigest md=null;  
  try {  
   md = MessageDigest.getInstance("MD5");  
   return md.digest(bytes);  
  } catch (NoSuchAlgorithmException e) {  
   e.printStackTrace();  
   return new byte[0];  
  }  
    
 }  
}