Instructions: Your task is to create a Java application that implements a simple dependency injection framework. Follow the steps outlined below to complete the assignment.

1. Define the Classes:

   • Create an interface called "DependencyInjector" with a single method "void injectDependencies(Object target)".
   • Implement the "DependencyInjector" interface with a class called "MyDependencyInjector" that provides an implementation for the "injectDependencies" method.

2. Implement the Dependency Injection Framework:

   • Create a class called "Container" that acts as the dependency injection container.
   • Add a private field in the "Container" class to store a mapping of dependencies.
   • Implement a method in the "Container" class, e.g., "registerDependency(Class<?> clazz)", to register dependencies.
   • Implement the "injectDependencies" method in the "MyDependencyInjector" class to perform the actual dependency injection.
   • Use reflection to scan the target object's fields and identify the ones that are annotated with your custom injection annotation.
   • Retrieve the corresponding dependency from the "Container" class and set it in the target object's field.
   • Handle any exceptions that may occur during the injection process.

3. Define the Classes to be Injected:

   • Create a class called "UserService" with a private field of type "UserRepository".
   • Annotate the "UserService" class field with your custom injection annotation.

4. Test the Dependency Injection:

   • In the main method of your application, create an instance of the "UserService" class.
   • Create an instance of the "Container" class and register the "UserRepository" as a dependency.
   • Create an instance of the "MyDependencyInjector" class and call the "injectDependencies" method, passing the "UserService" instance.
   • Verify that the "UserService" object has the "UserRepository" dependency properly injected.

5. Additional Functionality (Optional):

   • Implement another class and define additional dependencies.
   • Modify the "Container" and "MyDependencyInjector" classes to support injecting dependencies into the new class.
   • Test the updated implementation to ensure that the new dependencies are correctly injected.

Submission

• Fork the repository and push your changes.
• Once you finished your project, send a Pull Request. (Send only one Pull Request once you finish the assignment.)

Important Notes

• You are not allowed to share codes with your classmates. If detected, you will get NC.
• For pairs:
  • Individual's work will be checked from the commits.
  • Share tasks evenly and fairly.
  • To have a clearer understanding of pair programming:

    • Pair programming is an agile software development technique in which two programmers work together at one workstation. One, the driver, writes code while the other, the observer or navigator reviews each line of code as it is typed in. The two programmers switch roles frequently.

    • Wikipedia

• Remember to respect the code honor submission policy. All written code must be original. Presenting something as one’s own work when it came from another source is plagiarism and is forbidden.

• Plagiarism is a very serious thing in all American academic institutions and is guarded against vigilantly by every professor.

Useful GIT Videos

• Command Line GIT
  • https://www.youtube.com/watch?v=USjZcfj8yxE
• GitHub Desktop
  • https://www.youtube.com/watch?v=0nzJXJAhlsk
• Pull Request
  • https://www.youtube.com/watch?v=For9VtrQx58