Java import certificate into keystore

ImportCertificateInKeyStore.java

package io.klib.certificates;

import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.KeyStore;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;

public class ImportCertificateInKeyStore {

	public static void main(String[] argv) throws Exception {
		String certFile = "";
		String certAlias = "";
		String keystoreFileString = "";
		String keystorePass = "";

		for (int i = 0; i < argv.length; i++) {
			String[] argArray = argv[i].split("=");
			String key = argArray[0];
			String value = argArray[1];
			switch (key) {
			case "certFile":
				certFile = value;
				break;
			case "certAlias":
				certAlias = value;
				break;
			case "keystoreFile":
				keystoreFileString = value;
				break;
			case "keystorePass":
				keystorePass = value;
				break;
			default:
				System.out.format("wrong argument specified %s", key);
				System.exit(1);
				break;
			}
		}
		if (certFile == "" || certAlias == "" || keystoreFileString == "" || keystorePass == "") {
			System.out.format(
					"\nfollowing args are required \ncertFile=%s\ncertAlias=%s\nkeystoreFile=%s\nkeystorePass=%s\n\n",
					certFile, certAlias, keystoreFileString, keystorePass);
			System.exit(1);
		}
		System.out.format("\nimporting certificate %s with alias %s into keystore %s\n\n", certFile, certAlias,
				keystoreFileString);

		FileInputStream is = new FileInputStream(keystoreFileString);

		KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
		keystore.load(is, keystorePass.toCharArray());

		char[] password = keystorePass.toCharArray();

		//////

		CertificateFactory cf = CertificateFactory.getInstance("X.509");
		InputStream certstream = fullStream(certFile);
		Certificate certs = cf.generateCertificate(certstream);

		///
		File keystoreFile = new File(keystoreFileString);
		// Load the keystore contents
		FileInputStream in = new FileInputStream(keystoreFile);
		keystore.load(in, password);
		in.close();

		// Add the certificate
		keystore.setCertificateEntry(certAlias, certs);

		// Save the new keystore contents
		FileOutputStream out = new FileOutputStream(keystoreFile);
		keystore.store(out, password);
		out.close();
		System.out.format("finished\n");
	}

	private static InputStream fullStream(String fname) throws IOException {
		FileInputStream fis = new FileInputStream(fname);
		DataInputStream dis = new DataInputStream(fis);
		byte[] bytes = new byte[dis.available()];
		dis.readFully(bytes);
		ByteArrayInputStream bais = new ByteArrayInputStream(bytes);
		return bais;
	}
}