java.security.InvalidKeyException:Unsupported Key Size:1bytes

This exception is thrown when trying to use a key that has an unsupported size. In this case, the key size is only 1 byte, which is too small for most cryptographic algorithms.

To fix this issue, you need to use a key with a valid size for the algorithm you're using. For example, if you're using AES encryption, the key size should be either 128 bits, 192 bits, or 256 bits. You can generate a valid key using a key generator class provided by the Java Cryptography Architecture (JCA).

Here's an example of how to generate a 128-bit AES key:

KeyGenerator keyGen = KeyGenerator.getInstance("AES");
keyGen.init(128);
SecretKey key = keyGen.generateKey();

Once you have a valid key, you can use it to encrypt or decrypt data without encountering the "Unsupported Key Size" exception.