用于生成MD5

public class MD5 {


public static String getMD5(String instr) {
String s = null;
char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'a', 'b', 'c', 'd', 'e', 'f' };
try {
java.security.MessageDigest md = java.security.MessageDigest
.getInstance("MD5");
md.update(instr.getBytes());
byte tmp[] = md.digest();
char str[] = new char[16 * 2];
int k = 0;
for (int i = 0; i < 16; i++) {
byte byte0 = tmp[i];
str[k++] = hexDigits[byte0 >>> 4 & 0xf];
str[k++] = hexDigits[byte0 & 0xf];
}
s = new String(str).toUpperCase();


} catch (Exception e) {


}
return s;
}


}