Three methods of extended functions

1. Based on inheritance-method override (* Object Instantiation must be controllable, and the instantiation process cannot be controlled. The first inheritance method cannot be used for extension)

* This type is not recommended for enterprise development:

2: Use the decoration mode packaging class to enhance the original behavior:

Key points for compiling the decoration class: Compile the class, inherit the decorated class, and provide a constructor. The method parameter is the decorated object;

For example, bufferreader is designed in decorative mode.

3: Use Dynamic proxy-execution in memory based on bytecode class.

The third type is usually used in development.