import java.security.Key;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

/*...*/

public static String encrypt(String key, String clearText) throws Exception{    	 
	Cipher c = Cipher.getInstance(RC4_NAME);
	Key mainKey = new SecretKeySpec(key.getBytes(), "RC4");
	c.init(Cipher.ENCRYPT_MODE, mainKey);
	byte[] encVal = c.doFinal(clearText.getBytes(UNICODE));         
	String encryptedValue =  Base64.encodeToString(encVal, false);
	return encryptedValue;         
}

public static String decrypt(String key, String encryptedData) throws Exception {    	
	Cipher c = Cipher.getInstance(RC4_NAME);
	Key mainKey = new SecretKeySpec(key.getBytes(), "RC4");
	c.init(Cipher.DECRYPT_MODE, mainKey);
	byte[] decordedValue = Base64.decode(encryptedData);
	byte[] decValue = c.doFinal(decordedValue);
	String decryptedValue = new String(decValue, UNICODE);        
	return decryptedValue;        
}