The Reflect Part

Posted 2020-09-27 pp_crz_coder

The reflect part has many advantages.I heard that reflect is widely used in many frames.

In this part:

　　1.Common method to get Class object:

　　　　a)Class clazz = Class.forName(Qualified Name);

　　　　b)Class clazz = Person.getClass();

　　　　c)Class clazz = Person.class;

　　2.Get the method:

　　　　a)Method[] methods = clazz.getDeclaredMethods();

　　　　b)Method method = clazz.getDeclaredMethod(method‘s name, parameters‘ class);

　　3.Get the constructor:

　　　　a)Constructor[] cons = clazz.getDeclaredConstructors();

　　　　b)Constructor con = clazz.getDeclaredConstructor(parameters‘ class);

　　4.Get the object:

　　　　a)Person person = (Person) clazz.newInstance();

　　　　b)Person person = (Person) constructor.newInstrance(parameters);

　　5.Call the method:

　　　　method.invoke(object,parameters);

 

What‘s going on when use the reflect?

　　1.Load the person.class

　　2.Create space in the heap memory

　　3.Initialize the fields of this object

　　4.Display the initialization

　　5.Initialize the constructor

 

If you can use config file to configure the interface or class path, the code‘s extension will be very convenient.

For exmaple:

　　If these is a file called config.txt. And the config.txt include the class or interface‘s path from the first line.

　　main{

　　BufferedReader reader = new BufferedReader(new FileReader(config file path));

　　String line = reader.readLine();

　　Class clazz = Class.forName(line);

　　MyInterface mi = (MyInterface) clazz.newInstance();

　　mi.test();

　　}

 

If you want to use another Class object you can modify the config.txt , that is not a bad choice.