JAVA - 【String】md5加密與進制轉換

MD5/SHA加密：

import java.io.FileNotFoundException;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class Test {
	public static void main(String[] args) throws FileNotFoundException {
		
		try {
			MessageDigest md5Instance = MessageDigest.getInstance("md5");
			byte[] secretBytes1 = md5Instance.digest("tom".getBytes());
			String md5Code = new BigInteger(1,secretBytes1).toString(16);
			for(int i=0;i<32-md5Code.length();i++){
				md5Code = "0" + md5Code;
			}
			System.out.println(md5Code);
			// 34b7da764b21d298ef307d04d8152dc5
			
			
			String a = "asdvf";
			System.out.println(new BigInteger(1,a.getBytes()).toString());
			//System.out.println(new BigInteger(1,a.getBytes()).toString(2));
			byte[] byteArray = new BigInteger("418547791462").toByteArray();
			for (int i = 0; i < byteArray.length; i++) {
				System.out.print((char)byteArray[i]);
			}
			// 418547791462
			
			
			MessageDigest shaInstance = MessageDigest.getInstance("sha");
			byte[] secretBytes2 = shaInstance.digest("jerry".getBytes());
			String shaCode = new BigInteger(1,secretBytes2).toString(16);
			for(int i=0;i<40-shaCode.length();i++){
				shaCode = "0" + shaCode;
			}
			System.out.println(shaCode);
			// asdvf75926e095b28dd773adde5bade93e4836b1d92fc
			
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}
		
	}
}

進制轉換：

String a = "1234";
int aa = Integer.valueOf(a);
String hexRes = Integer.toString(aa, 16);
System.out.println(hexRes);