hash function demonstration program structure

Overall Structure The entire system is primarily divided into two major modules: the HashUI module (responsible for graphical user interface-related operations) and the HashCalculator module (responsible for the specific hash calculation functionality). These two modules work together to implement the functionality of the entire hash function demonstration program. ### HashUI Module - **Input Component Section:** - **JTextField (Input Text Field):** Used to receive the original string content that the user wants to hash. The user inputs text information here, which serves as the data source for the entire calculation process. - **JButton (Calculate Hash Button):** Associated with the input text field, this button triggers the hash calculation operation when clicked, acting as the "switch" to start the entire calculation process. - **Result Display Section:** - **JTextArea (Result Text Area):** Used to display the final result of the hash calculation. It receives the hash values calculated by the HashCalculator module and displays them to the user in an appropriate format (e.g., MD5 hash values, SHA-256 hash values, etc., each displayed on a separate line). - **Interaction Logic:** - **Button's ActionListener (Event Listener):** Listens for click events on the JButton. When the button is clicked, it first retrieves the input text from the JTextField, performs simple input validation (checking if it is empty). If the validation passes, it creates a HashCalculator object, calls its corresponding hash calculation method to obtain the hash value, and then sets these values in the JTextArea for display. If the validation fails, it pops up a prompt box informing the user that the input is invalid. ### HashCalculator Module - **MD5 Hash Calculation Method:** - **getMD5Hash:** Receives the input string passed from the HashUI module, uses the Java MessageDigest class to calculate the hash according to the standard MD5 algorithm. It first obtains an "MD5" algorithm instance, updates the data, performs the hash calculation to get the byte array result, and then converts the byte array into a hexadecimal string format to be returned to the HashUI module for display. - **SHA-256 Hash Calculation Method:** - **getSHA256Hash:** Similarly receives the input string, uses the MessageDigest class, but here it uses the "SHA-256" algorithm instance to complete similar calculation steps. The final result is also a hexadecimal representation of the hash value, which is returned to the HashUI module. - **Remainder Hash Calculation Method (for extended comparison reference):** - **getRemainderHash:** Sums the ASCII values of the characters in the input string and then performs a modulo operation with a fixed large prime number to obtain a hash result in integer form, which is returned to the HashUI module. (Although this simple algorithm is mostly used for comparison and understanding, it is rarely applied in actual security-related scenarios.) ### Module Relationships - **HashUI Module depends on the HashCalculator Module** to complete the specific hash calculation tasks. It creates a HashCalculator object and calls its public hash calculation methods (such as getMD5Hash, getSHA256Hash, etc.) to obtain the hash values that need to be displayed. - **The HashCalculator Module provides services to the HashUI Module.** It receives the input string passed from HashUI, performs calculations according to different algorithm requirements, and returns the corresponding hash value results for HashUI to display to the user on the interface.