MD5加密

import java.security.*;
import java.util.*;

public class MD5
{
private String inStr;
private MessageDigest md5;

/**
* Constructs the MD5 object and sets the string whose MD5 is to be computed.
*
* @param inStr the <code>String</code> whose MD5 is to be computed
*/
public MD5(String inStr)
{
this.inStr = inStr;
try
{
this.md5 = MessageDigest.getInstance("MD5");
}
catch (Exception e)
{
System.out.println(e.toString());
e.printStackTrace();
}
}

/**
* Computes the MD5 fingerprint of a string.
*
* @return the MD5 digest of the input <code>String</code>
*/
public String compute()
{
// convert input String to a char[]
// convert that char[] to byte[]
// get the md5 digest as byte[]
// bit-wise AND that byte[] with 0xff
// prepend "0" to the output StringBuffer to make sure that we don't end up with
// something like "e21ff" instead of "e201ff"

char[] charArray = this.inStr.toCharArray();

byte[] byteArray = new byte[charArray.length];

for (int i=0; i<charArray.length; i++)
byteArray[i] = (byte) charArray[i];

byte[] md5Bytes = this.md5.digest(byteArray);

StringBuffer hexValue = new StringBuffer();

for (int i=0; i<md5Bytes.length; i++)
{
int val = ((int) md5Bytes[i] ) & 0xff;
if (val < 16) hexValue.append("0");
hexValue.append(Integer.toHexString(val));
}

return hexValue.toString();
}


public static void main(String[] args)
{
MD5 md5=new MD5("abc");
String postString = md5.compute();
System.out.println(postString);
if(postString.equals("900150983cd24fb0d6963f7d28e17f72"))
{
System.out.println("true");
}
else
System.out.println("false");
}

}