Java Key Technologies (24) using reflection to access parameterized types of generics

1.1. accessing parameterized types with reflection

Use the reflection mechanism to get information about a subset of parameterized types.

 Public classGENERICPARAMETERTEST5 {Static  classbase{}Static classGeneric<textendsBase>{  PublicT Work (list<t>list) {returnList.get (0);}  Publict work (t obj) {returnobj;}}  Public Static voidMain (string[] args) {Try {  //Public T-work (list<t> List) {Method method1= Generic.class. GetMethod ("Work", List.class); System.out.println (Method1.getparameters () [0].gettype ()); Type T1= Method1.getgenericparametertypes () [0]; Parameterizedtype PT=(parameterizedtype) T1; System.out.println ("Rawtype:" +Pt.getrawtype ()+ "Actualtype:" + pt.getactualtypearguments () [0].gettypename ()); System.out.println ("-------------"); //Public T-work (T obj) {Method method2= Generic.class. GetMethod ("Work", Base.class); System.out.println (Method2.getparameters () [0].gettype ()); Type T2= Method2.getgenericparametertypes () [0]; Typevariable<?> TV =(typevariable) T2; System.out.println (Tv.gettypename ()); Genericdeclaration GD=tv.getgenericdeclaration (); System.out.println (Gd.gettypeparameters () [0]); } Catch(Nosuchmethodexception |SecurityException e) {e.printstacktrace (); }}}

The results of the operation are as follows:

Interface Java.util.List

Rawtype:interface Java.util.listactualtype:t

-------------

Class Com.test.javatechnology.genericparameter.genericparametertest5$base

T

T

Java Key Technologies (24) using reflection to access parameterized types of generics