public class Another {
class Atom implements Runnable {
public int i;
public Atom() {
System.
out.println(
"createAtom");
}
public void run() {
synchronized (Atom.
class) {
StaticClass.run();
}
}
}
static class StaticAtom implements Runnable {
public int i;
public StaticAtom() {
i++;
System.
out.println(
"creatoeStaticAtion"+i);
}
/**
* 静态内部类的调用是线程安全的
*/
public void run() {
StaticClass.run();
}
}
public static void main(String[] args) throws Exception {
(
new Another()).testSatic();
// Atom atom = new Atom(); 不能通过应为静态方法的调用没有实例，因为非静态内部类必须依赖外部的类的实例创建
for (
int i = 0; i < 100; i++) {
StaticAtom sa =
new StaticAtom();
Thread t =
new Thread(sa);
t.start();
}
}
public void testSatic() throws Exception {
// StaticAtom sa =new StaticAtom(); 可以编译通过。非静态方法可以创建静态内部类的实例
for (
int i = 0; i < 5; i++) {
Atom atom =
new Atom();
Thread t =
new Thread(atom);
t.start();
}
}
}
public class StaticClass{
private static int i;
private StaticClass() {
}
public static void run() {
i++;
System.
out.println(
"类变量的值是"+i);
}
}
注意静态内部类的run调用不需要sync也是threadsafe的，内部类的run需要sync的。
