反射机制

最新推荐文章于 2025-10-02 22:48:14 发布

转载最新推荐文章于 2025-10-02 22:48:14 发布 · 417 阅读

文章标签：

#string #class #object

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本文详细介绍了Java反射机制的应用，包括加载类、获取方法、访问字段等操作，并通过实例展示了如何利用反射进行方法调用和字段操作。

文章来源： http://czh.iteye.com/blog/604262

package com;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

class Test{
   private String str = "123";
   static{
       System.out.println("Test Load");
   }

   public void test(){
       System.out.println("test method");
   }

   public static void test1(String name){
       System.out.println("test1 method");
   }
}
public class Reflect_class {
   public static void main(String args[]){
       System.out.println(Test.class);

       try{
           Test test = new Test();
           //加载TEST
           Class testClass = Class.forName("com.Test");
               Object object = testClass.newInstance();

           //获取Method
           Method[] testMethod = testClass.getDeclaredMethods();
           System.out.println(testMethod[0].getName());
           testMethod.getClass();


           //获取fields的相关信息
           Field fields[] = testClass.getDeclaredFields();
           for(Field field : fields){
               System.out.println(field.getName());
               System.out.println(field.getType());
               System.out.println("field type is class ?" + field.getType().isInstance(new String()));
           }
           try {
               //调用方法
               Method method = testClass.getDeclaredMethod("test", new Class[]{});
               method.invoke(test, new Object[]{});
               Method method2 = testClass.getDeclaredMethod("test1", new Class[]{String.class});
               method2.invoke(test, new Object[]{new String("new String")});
           } catch (SecurityException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
           } catch (NoSuchMethodException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
           } catch (IllegalArgumentException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
           } catch (IllegalAccessException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
           } catch (InvocationTargetException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
           }
       } catch(ClassNotFoundException e){
           e.printStackTrace();
       } catch (InstantiationException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       } catch (IllegalAccessException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       }
   }
}