callmethoddemo.java

java的反射机制的代码实例

import java.lang.reflect.*;
public class CallMethodDemo 
{
	public static void main(String[] args) 
	{
		
		//获取Class对象用来描述自定义类Employee
		Class c = Employee.class;
		
		//用于定义所调用方法中，所包含的参数形式
		Class parameter_Type[] = new Class[3];
		parameter_Type[0] = String.class;
		parameter_Type[1] = Integer.TYPE;
		parameter_Type[2] = String.class;
		
		//用于定义运行时调用的方法的实际参数
		Object value[] = new Object[3];
		value[0] = new String("wangxyw");
		value[1] = new Integer(24);
		value[2] = new String("male");
		
		try 
		{
//创建方法对象，该方法参数名为"setAll"，参数形式为Class型数组parameter_Type定义的形式
			Method m = c.getMethod("setAll",parameter_Type);
			
			//运行时创建类对象
			Object obj = null;
			obj = c.newInstance();
			Employee em = (Employee)obj;
			
			//运行时调用类对象中的方法
			Object r = m.invoke(em, value);
			
			//显示调用方法后，类对象中的属性值
			System.out.println(em.get_name());
			System.out.println(em.get_age());
			System.out.println(em.get_sex());
		} 
		catch (SecurityException e1) {e1.printStackTrace();} 
		catch (NoSuchMethodException e1) {e1.printStackTrace();}
		catch (InstantiationException e) {e.printStackTrace();}
		catch (IllegalAccessException e) {e.printStackTrace();}
		catch(InvocationTargetException e) {e.printStackTrace();}
	} 

}

class Employee   //自定义类
{
	private String name;
	private int age;
	private String sex;
	
	public Employee() //无参数构造方法
	{}
	
	//含参数构造方法
	public Employee(String name,int age,String sex)
	{
		this.name = name;
		this.age = age;
		this.sex = sex;
	}
	
	//获取自定义类属性值方法	
	public String get_name(){return name;}
	public int get_age(){return age;}
	public String get_sex(){return sex;}
	
	//自定义类改变属性值方法	
	public void setAll(String name,int age,String sex)
	{
		this.name = name;
		this.age = age;
		this.sex = sex;
	}
}