Introduction to the Java Reflection Mechanism 02

The mechanism and implementation of Field object

1. Field Object Overview

1) The Java.lang.reflect.Field class, which is a class used to represent property objects in a class, in an interface.

2) You can manipulate the information for all properties and properties, such as private and public, in a class.

2. Introduction to the common methods of Field objects

Method name	Interpretation
GetName ()	Get Property name
GetType ()	Get Property type
Get (Object obj)	Gets the value of this property in the Obj object
Set (Object obj,object value)	Assign value to the BoJ property
Setaccessible (Boolean)	Enable/disable access control permissions

 PackageCom.rainmer.main;ImportJava.lang.reflect.Field;ImportCom.rainmer.bean.Book; Public classFieldtest {//The method is used to get the properties in the class using the passed class object .     Public voidShow (Class C1) {field[] fi= C1.getdeclaredfields ();//can get all properties, public or privateSystem.out.println ("~~~~~~~~~~~~ gets all attributes (including private) ~~~~~~~~~~~~~~");  for(Field ff:fi) {System.out.println (Ff.getname ());        System.out.println (Ff.gettype ()); } System.out.println ("~~~~~~~~~~~~ can only get common attribute ~~~~~~~~~~~~~~"); Field[] Fi1= C1.getfields ();//only common properties can be obtained         for(Field ff:fi1) {System.out.println (Ff.getname ());//Property nameSystem.out.println (Ff.gettype ());//Property Type        }    }        //This method is used to get the property and the value of the property using the entity class object passed in .     Public voidShow (Object ob) {System.out.println ("~~~~~~~~~~~~~~~ gets the property and the value of the property through the entity class object ~~~~~~~~~~~~~~~~~~~"); Class CL=Ob.getclass (); Field[] fi=Cl.getdeclaredfields (); Try{             for(Field ff:fi) {ff.setaccessible (true);//enable access, not to turn private properties into shared propertiesSystem.out.println (Ff.getname () + "value" +ff.get (ob)); }        }Catch(Exception e) {e.printstacktrace (); }    }         Public Static voidMain (string[] args) {book Bo=NewBook (); Bo.setid (1); Bo.setname ("Fighting the heavens."); Bo.settype (Fantasy); Fieldtest ft=Newfieldtest (); Ft.show (book.class);            Ft.show (BO); }}

Operation Result:

Called the SetName method
~~~~~~~~~~~~ get all attributes (including private) ~~~~~~~~~~~~~~
Id
Int
Name
Class Java.lang.String
Type
Class Java.lang.String
~~~~~~~~~~~~ can only get common attributes ~~~~~~~~~~~~~~
Type
Class Java.lang.String
~~~~~~~~~~~~~~~ gets the property and the value of the property through the entity class object ~~~~~~~~~~~~~~~~~~~
ID value 1
Name Value bucket Break Sky
Type value Fantasy

Introduction to the Java Reflection Mechanism 02