Java Hex 16進制的 byte String 轉換類

package mobi.dzs.android.util;

import java.util.Locale;

/**
 * 16進制值與String/Byte之間的轉換
 * @author JerryLi
 * @email [e-mail]
 * @data 2011-10-16
 * */
public class CHexConver
{
    private final static char[] mChars = "0123456789ABCDEF".toCharArray();
    private final static String mHexStr = "0123456789ABCDEF";  
    /** 
     * 檢查16進制字符串是否有效
     * @param sHex String 16進制字符串
     * @return boolean
     */  
    public static boolean checkHexStr(String sHex){  
        String sTmp = sHex.toString().trim().replace(" ", "").toUpperCase(Locale.US);
        int iLen = sTmp.length();
        
        if (iLen > 1 && iLen%2 == 0){
            for(int i=0; i<iLen; i++)
                if (!mHexStr.contains(sTmp.substring(i, i+1)))
                    return false;
            return true;
        }
        else
            return false;
    }
    
    /** 
     * 字符串轉換成十六進制字符串
     * @param str String 待轉換的ASCII字符串
     * @return String 每個Byte之間空格分隔，如: [61 6C 6B]
     */  
    public static String str2HexStr(String str){  
        StringBuilder sb = new StringBuilder();
        byte[] bs = str.getBytes();  
        
        for (int i = 0; i < bs.length; i++){  
            sb.append(mChars[(bs[i] & 0xFF) >> 4]);  
            sb.append(mChars[bs[i] & 0x0F]);
            sb.append(' ');
        }  
        return sb.toString().trim();  
    }
    
    /** 
     * 十六進制字符串轉換成 ASCII字符串
     * @param str String Byte字符串
     * @return String 對應的字符串
     */  
    public static String hexStr2Str(String hexStr){  
        hexStr = hexStr.toString().trim().replace(" ", "").toUpperCase(Locale.US);
        char[] hexs = hexStr.toCharArray();  
        byte[] bytes = new byte[hexStr.length() / 2];  
        int iTmp = 0x00;;  

        for (int i = 0; i < bytes.length; i++){  
            iTmp = mHexStr.indexOf(hexs[2 * i]) << 4;  
            iTmp |= mHexStr.indexOf(hexs[2 * i + 1]);  
            bytes[i] = (byte) (iTmp & 0xFF);  
        }  
        return new String(bytes);  
    }
    
    /**
     * bytes轉換成十六進制字符串
     * @param b byte[] byte數組
     * @param iLen int 取前N位處理 N=iLen
     * @return String 每個Byte值之間空格分隔
     */
    public static String byte2HexStr(byte[] b, int iLen){
        StringBuilder sb = new StringBuilder();
        for (int n=0; n<iLen; n++){
            sb.append(mChars[(b[n] & 0xFF) >> 4]);
            sb.append(mChars[b[n] & 0x0F]);
            sb.append(' ');
        }
        return sb.toString().trim().toUpperCase(Locale.US);
    }
    
    /**
     * bytes字符串轉換為Byte值
     * @param src String Byte字符串，每個Byte之間沒有分隔符(字符范圍:0-9 A-F)
     * @return byte[]
     */
    public static byte[] hexStr2Bytes(String src){
        /*對輸入值進行規范化整理*/
        src = src.trim().replace(" ", "").toUpperCase(Locale.US);
        //處理值初始化
        int m=0,n=0;
        int iLen=src.length()/2; //計算長度
        byte[] ret = new byte[iLen]; //分配存儲空間
        
        for (int i = 0; i < iLen; i++){
            m=i*2+1;
            n=m+1;
            ret[i] = (byte)(Integer.decode("0x"+ src.substring(i*2, m) + src.substring(m,n)) & 0xFF);
        }
        return ret;
    }

    /**
     * String的字符串轉換成unicode的String
     * @param strText String 全角字符串
     * @return String 每個unicode之間無分隔符
     * @throws Exception
     */
    public static String strToUnicode(String strText)
        throws Exception
    {
        char c;
        StringBuilder str = new StringBuilder();
        int intAsc;
        String strHex;
        for (int i = 0; i < strText.length(); i++){
            c = strText.charAt(i);
            intAsc = (int) c;
            strHex = Integer.toHexString(intAsc);
            if (intAsc > 128)
                str.append("\\u");
            else // 低位在前面補00
                str.append("\\u00");
            str.append(strHex);
        }
        return str.toString();
    }
    
    /**
     * unicode的String轉換成String的字符串
     * @param hex String 16進制值字符串 （一個unicode為2byte）
     * @return String 全角字符串
     * @see CHexConver.unicodeToString("\\u0068\\u0065\\u006c\\u006c\\u006f")
     */
    public static String unicodeToString(String hex){
        int t = hex.length() / 6;
        int iTmp = 0;
        StringBuilder str = new StringBuilder();
        for (int i = 0; i < t; i++){
            String s = hex.substring(i * 6, (i + 1) * 6);
            // 將16進制的string轉為int
            iTmp = (Integer.valueOf(s.substring(2, 4), 16) << 8) | Integer.valueOf(s.substring(4), 16);
            // 將int轉換為字符
            str.append(new String(Character.toChars(iTmp)));
        }
        return str.toString();
    }
}