字符串，int，十六进制间转换

      public class TypeConvert
       {  
02.    /* 字符串转byte[] 
03.        这个方法转换后的结果是会多一些 48字符进来的就是代表的是0不知道为什么，但是可以只是取出指定的字符串就行了 
04.    */  
05.  public static byte[] hexStringToBytes(String hexString) 
     {  
       if (hexString == null || hexString.equals(""))
        {         
                 return null;  

   }  

    hexString = hexString.toUpperCase();  

    int length = hexString.length() / 2;  

    char[] hexChars = hexString.toCharArray();  

    byte[] d = new byte[length];  

    for (int i = 0; i < length; i++) {  

        int pos = i * 2;  

        d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));  

    }  

    return d;  

}  

17.      
18.    /* byte转short */  
19.    public final static short getShort(byte[] buf, boolean asc, int len) {  
20.        short r = 0;  
21.        if (asc)  
22.          for (int i = len - 1; i >= 0; i--) {  
23.            r <<= 8;  
24.            r |= (buf[i] & 0x00ff);  
25.          }  
26.        else  
27.          for (int i = 0; i < len; i++) {  
28.            r <<= 8;  
29.            r |= (buf[i] & 0x00ff);  
30.          }  
31.          
32.        return r;  
33.    }  
34.      
35.    /* B2 -> 0xB2 */  
36.    public static int stringToByte(String in, byte[] b) throws Exception {   
37.        if (b.length < in.length() / 2) {   
38.            throw new Exception("byte array too small");   
39.        }  
40.          
41.        int j=0;  
42.        StringBuffer buf = new StringBuffer(2);   
43.        for (int i=0; i<in.length(); i++, j++) {   
44.            buf.insert(0, in.charAt(i));   
45.            buf.insert(1, in.charAt(i+1));   
46.            int t = Integer.parseInt(buf.toString(),16);   
47.            System.out.println("byte hex value:" + t);   
48.            b[j] = (byte)t;  
49.            i++;   
50.            buf.delete(0,2);   
51.        }   
52.          
53.        return j;  
54.    }  
55.      
56.    /* byte to  int */  
57.    public final static int getInt(byte[] buf, boolean asc, int len) {  
58.        if (buf == null) {  
59.          throw new IllegalArgumentException("byte array is null!");  
60.        }  
61.        if (len > 4) {  
62.          throw new IllegalArgumentException("byte array size > 4 !");  
63.        }  
64.        int r = 0;  
65.        if (asc)  
66.          for (int i = len - 1; i >= 0; i--) {  
67.            r <<= 8;  
68.            r |= (buf[i] & 0x000000ff);  
69.          }  
70.        else  
71.          for (int i = 0; i < len; i++) {  
72.            r <<= 8;  
73.            r |= (buf[i] & 0x000000ff);  
74.          }  
75.        return r;  
76.    }  
77.      
78.    /* int -> byte[] */  
79.    public static byte[] intToBytes(int num) {  
80.       byte[] b = new byte[4];  
81.       for (int i = 0; i < 4; i++) {  
82.        b[i] = (byte) (num >>> (24 - i * 8));  
83.       }  
84.        
85.       return b;  
86.    }  
87.      
88.    /* short to byte[] */  
89.    public static byte[] shortToBytes(short num) {  
90.       byte[] b = new byte[2];  
91.         
92.       for (int i = 0; i < 2; i++) {  
93.           b[i] = (byte) (num >>> (i * 8));  
94.       }  
95.         
96.       return b;  
97.    }  
98.      
99.    /* byte to String */  
100.    private static char findHex(byte b) {   
101.        int t = new Byte(b).intValue();   
102.        t = t < 0 ? t + 16 : t;   
103.  
104.        if ((0 <= t) &&(t <= 9)) {   
105.        return (char)(t + '0');   
106.        }   
107.  
108.        return (char)(t-10+'A');   
109.    }   
110.    public static String byteToString(byte b) {   
111.        byte high, low;   
112.        byte maskHigh = (byte)0xf0;   
113.        byte maskLow = 0x0f;   
114.  
115.        high = (byte)((b & maskHigh) >> 4);   
116.        low = (byte)(b & maskLow);   
117.  
118.        StringBuffer buf = new StringBuffer();   
119.        buf.append(findHex(high));   
120.        buf.append(findHex(low));   
121.  
122.        return buf.toString();   
123.    }  
124.      
125.    /* short -> byte */  
126.    public final static byte[] getBytes(short s, boolean asc) {  
127.        byte[] buf = new byte[2];  
128.        if (asc)      for (int i = buf.length - 1; i >= 0; i--) {        buf[i] = (byte) (s & 0x00ff);  
129.            s >>= 8;  
130.          }  
131.        else  
132.          for (int i = 0; i < buf.length; i++) {  
133.            buf[i] = (byte) (s & 0x00ff);  
134.            s >>= 8;  
135.          }  
136.        return buf;  
137.      }  
138.    /* int -> byte[] */  
139.      public final static byte[] getBytes(int s, boolean asc) {  
140.        byte[] buf = new byte[4];  
141.        if (asc)  
142.          for (int i = buf.length - 1; i >= 0; i--) {  
143.            buf[i] = (byte) (s & 0x000000ff);  
144.            s >>= 8;  
145.          }  
146.        else  
147.          for (int i = 0; i < buf.length; i++) {  
148.            buf[i] = (byte) (s & 0x000000ff);  
149.            s >>= 8;  
150.          }  
151.        return buf;  
152.      }  
153.        
154.      /* long -> byte[] */  
155.      public final static byte[] getBytes(long s, boolean asc) {  
156.        byte[] buf = new byte[8];  
157.        if (asc)  
158.          for (int i = buf.length - 1; i >= 0; i--) {  
159.            buf[i] = (byte) (s & 0x00000000000000ff);  
160.            s >>= 8;  
161.          }  
162.        else  
163.          for (int i = 0; i < buf.length; i++) {  
164.            buf[i] = (byte) (s & 0x00000000000000ff);  
165.            s >>= 8;  
166.          }  
167.        return buf;  
168.      }  
169.        
170.      /* byte[]->int */  
171.      public final static int getInt(byte[] buf, boolean asc) {  
172.        if (buf == null) {  
173.          throw new IllegalArgumentException("byte array is null!");  
174.        }  
175.        if (buf.length > 4) {  
176.          throw new IllegalArgumentException("byte array size > 4 !");  
177.        }  
178.        int r = 0;  
179.        if (asc)  
180.          for (int i = buf.length - 1; i >= 0; i--) {  
181.            r <<= 8;  
182.            r |= (buf[i] & 0x000000ff);  
183.          }  
184.        else  
185.          for (int i = 0; i < buf.length; i++) {  
186.            r <<= 8;  
187.            r |= (buf[i] & 0x000000ff);  
188.          }  
189.        return r;  
190.      }  
191.      /* byte[] -> long */  
192.      public final static long getLong(byte[] buf, boolean asc) {  
193.        if (buf == null) {  
194.          throw new IllegalArgumentException("byte array is null!");  
195.        }  
196.        if (buf.length > 8) {  
197.          throw new IllegalArgumentException("byte array size > 8 !");  
198.        }  
199.        long r = 0;  
200.        if (asc)  
201.          for (int i = buf.length - 1; i >= 0; i--) {  
202.            r <<= 8;  
203.            r |= (buf[i] & 0x00000000000000ff);  
204.          }  
205.        else  
206.          for (int i = 0; i < buf.length; i++) {  
207.            r <<= 8;  
208.            r |= (buf[i] & 0x00000000000000ff);  
209.          }  
210.        return r;  
211.      }  
212.}