it2021123 / hashmap Goto Github PK

Download the Project Files
    Download the HashMap.zip file from the provided source.

Extract the Files
    Extract the HashMap.zip file to a directory of your choice.

Open the Command Line
    On Linux, you can open the terminal using Ctrl+Alt+T.

Navigate to the Project Directory
    Use the cd command to navigate to the directory where you extracted the files.
                    
        cd path/to/extracted/files

Run the following Maven command to clean and package the project. This command is a combination of two Maven commands:

               mvn clean package

After the build is complete, navigate to the newly created target directory:

             cd target

Run the program using the following command:


    java -jar HashMap-Hash.jar

Start the Program
    Once the program is running, you can start interacting with it by typing the path to the .txt file you want to process and pressing Enter.

Absolute Path for Multiple Root Directories
    If your system has multiple root directories (common in Windows), make sure to type the absolute path of the file. On Linux, there is only one root directory (/).

File Format
    The application can only read .txt files. Ensure the file you are trying to process is in .txt format.

Performance Improvement
    Typing the absolute path of the file can significantly improve the speed of the program.

File Extension
    Remember to manually include the .txt extension after the file name. For example, if the file name is tryhard.txt, you should enter:

    name -> tryhard
    extension -> .txt

Key-Value Pair Storage: Stores data in key-value pairs, allowing efficient retrieval of values based on their associated keys.
Constant-Time Performance: Provides average constant-time performance for the basic operations (get and put), assuming the hash function disperses the elements properly among the buckets.
Null Keys and Values: Allows one null key and multiple null values.
Non-Synchronized: The HashMap class is not synchronized. If multiple threads access a hash map concurrently, and at least one of the threads modifies the map structurally, it must be synchronized externally.

put(K key, V value): Associates the specified value with the specified key in the map.
get(Object key): Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.
remove(Object key): Removes the mapping for a key from this map if it is present.
containsKey(Object key): Returns true if this map contains a mapping for the specified key.
size(): Returns the number of key-value mappings in the map.