浅谈java二进制、十进制、十六进制、字符串之间的相互转换

/*
  * 字节转10进制
  */
 public static int byte2Int(byte b){
  int r = (int) b;
  return r;
 }

/*
  * 10进制转字节
  */
 public static byte int2Byte(int i){
  byte r = (byte) i;
  return r;
 }

/*
  * 字节数组转16进制字符串
  */
 public static String bytes2HexString(byte[] b) {
  String r = "";
  
  for (int i = 0; i < b.length; i++) {
   String hex = Integer.toHexString(b[i] & 0xFF);
   if (hex.length() == 1) {
    hex = '0' + hex;
   }
   r += hex.toUpperCase();
  }
  
  return r;
 }

/*
  * 字符转换为字节
  */
 private static byte charToByte(char c) {
  return (byte) "0123456789ABCDEF".indexOf(c);
  }
 
 /*
  * 16进制字符串转字节数组
  */
 public static byte[] hexString2Bytes(String hex) {
   
   if ((hex == null) || (hex.equals(""))){
    return null;
   }
   else if (hex.length()%2 != 0){
    return null;
   }
   else{    
    hex = hex.toUpperCase();
    int len = hex.length()/2;
    byte[] b = new byte[len];
    char[] hc = hex.toCharArray();
    for (int i=0; i<len; i++){
     int p=2*i;
     b[i] = (byte) (charToByte(hc[p]) << 4 | charToByte(hc[p+1]));
    }
    return b;
   }   
   
 }

/*
  * 字节数组转字符串
  */
 public static String bytes2String(byte[] b) throws Exception {
  String r = new String (b,"UTF-8");  
  return r;
 }

/*
  * 字符串转字节数组
  */
 public static byte[] string2Bytes(String s){
  byte[] r = s.getBytes();
  return r;
 }

/*
  * 16进制字符串转字符串
  */
 public static String hex2String(String hex) throws Exception{
  String r = bytes2String(hexString2Bytes(hex));  
  return r;
 }

/*
  * 字符串转16进制字符串
  */
 public static String string2HexString(String s) throws Exception{
  String r = bytes2HexString(string2Bytes(s));  
  return r;
 }

public static void main(String[] args) throws Exception{  
  byte b1 = (byte) 45;
  System.out.println("1.字节转10进制:" + byte2Int(b1));
  
  int i = 89;
  System.out.println("2.10进制转字节:" + int2Byte(i));
  
  byte[] b2 = new byte[]{(byte)0xFF, (byte)0x5F, (byte)0x6, (byte)0x5A};
  System.out.println("3.字节数组转16进制字符串:" + bytes2HexString(b2));
  
  String s1 = new String("1DA47C");
  System.out.println("4.16进制字符串转字节数组:" + Arrays.toString(hexString2Bytes(s1)));
  
  System.out.println("5.字节数组转字符串:" + bytes2String(b2));
  
  System.out.println("6.字符串转字节数组:" + Arrays.toString(string2Bytes(s1)));
  
  System.out.println("7.16进制字符串转字符串:" + hex2String(s1));
  
  String s2 = new String("Hello!");
  System.out.println("8.字符串转16进制字符串:" + string2HexString(s2));
 }

1.字节转10进制:45
2.10进制转字节:89
3.字节数组转16进制字符串:FF5F065A
4.16进制字符串转字节数组:[29, -92, 124]
5.字节数组转字符串:?_Z
6.字符串转字节数组:[49, 68, 65, 52, 55, 67]
7.16进制字符串转字符串:?|
8.字符串转16进制字符串:48656C6C6F21