java 32位md5加密類

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class Test {

public static void main(String[] args) {
    Test test = new Test();
    System.out.println(test.encryption("12345678"));
}

/**
 * 
 * @param plainText
 *            明文
 * @return 32位密文
 */
public String encryption(String plainText) {
    String re_md5 = new String();
    try {
        MessageDigest md = MessageDigest.getInstance("MD5");
        md.update(plainText.getBytes());
        byte b[] = md.digest();

        int i;

        StringBuffer buf = new StringBuffer("");
        for (int offset = 0; offset < b.length; offset++) {
            i = b[offset];
            if (i < 0)
                i += 256;
            if (i < 16)
                buf.append("0");
            buf.append(Integer.toHexString(i));
        }

        re_md5 = buf.toString();

    } catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
    }
    return re_md5;
}

}</pre>