对java中Static 的理解

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在Java里关键字static 是属于类本身的,而并非属于类对象,所以说关键字static 代表的字段或者引用在类中只有被初始化一次(因为任何一个类载入内存时,只会载入一次,但却可以在内存地址中占无限个该类的实例(对象)),在带有关键字static的静态方法里不能使用非静态方法(因为当调用每个非静态方法里均隐藏了该类对象的引用this)

下面是测试代码片段:

public class MainApp
{
public static void main(String[]args)
{
for(int i=0;i<5;i++)
{
  NonStatic ns=new NonStatic();
  System.out.println("Class static address:"+ns.ns1);
  System.out.println("non static address:");
  System.out.println("Class non static address:"+ns.ns2);
}
}
}

class Test
{
public Test(){}
}

class NonStatic
{
public static Test ns1=new Test();
public Test ns2=new Test();
public NonStatic()
{

}
}

打印出来的效果:

Class static address:Test@1c78e57
non static address:
Class non static address:Test@5224ee
Class static address:Test@1c78e57
non static address:
Class non static address:Test@f6a746
Class static address:Test@1c78e57
non static address:
Class non static address:Test@15ff48b
Class static address:Test@1c78e57
non static address:
Class non static address:Test@affc70
Class static address:Test@1c78e57
non static address:
Class non static address:Test@1e63e3d