Java封装

class BigPerson
{
	private String name;
	private int age;
	void talk()
	{
		System.out.println("My name is "+ name +" and my age is "+age);
	}
	public  void setName(String string)
	{
		name = string;
	}
	public void setAge(int aage)
	{
		if(aage>=0)
			age = aage;
	}
	public String getNameString()
	{
		return name;
	}
	public int getAge()
	{
		return age;
	}
}
public class Person {
	public static void main(String args[])
	{
		BigPerson person = new BigPerson();
		person.setAge(-15);
		person.setName("Hou");
		person.talk();
	}
}

BigPerson person = new BigPerson();声明并实例化一个BigPerson对象

如果此时将talk()方法设置为private：

	private void talk()
	{
		System.out.println("My name is "+ name +" and my age is "+age);
	}

同时再添加一个say()方法：

	void say()
	{
		this.talk();
	}

便是在类内部调用方法。

此时person.talk();改为person.say();