一个简单的MD5,SHA1,SHA512加密的例子

public class Sha512 {

public String Encrypt(String strSrc,String encName) {
MessageDigest md=null;
String strDes=null;
byte[] bt=strSrc.getBytes();
try {
md=MessageDigest.getInstance(encName);

byte[] digest = md.digest(strSrc.getBytes());

strDes=byteToString(digest); //to HexString
/*
//for test
System.out.println("length: "+digest.length);
for(int i=0;i<digest.length;i++){
System.out.print(digest[i]+" ");
}
System.out.println();
*/
} catch (NoSuchAlgorithmException e) {
System.out.println(e);
}
return strDes;
}

private String byteToString(byte[] bts) {
String des="";
String tmp=null;
for (int i=0;i<bts.length;i++) {
//bts[i] & 0xFF <==> bts[i]+256 (if btd[i]<0)
tmp=(Integer.toHexString(bts[i] & 0xFF));
if (tmp.length()==1) {
des+="0";
}
des+=tmp;
}
return des;
}

public static void main(String[]args) {
MyEncrypt te=new MyEncrypt();
String strSrc="2008-8-8";
System.out.println("Source String:"+strSrc);
System.out.println("Encrypted String:");
System.out.println("Use MD5:"+te.Encrypt(strSrc,"MD5"));
System.out.println("Use SHA-1:"+te.Encrypt(strSrc,"SHA-1"));
System.out.println("Use SHA-512:"+te.Encrypt(strSrc,"SHA-512"));

}

}