饿汉模式
class InstanceDemo{
private static InstanceDemo ins;
static {
ins = new InstanceDemo();
}
private InstanceDemo() {
}
public InstanceDemo getInstance(){
return ins;
}
}
懒汉模式
class InstanceDemo{
private static InstanceDemo ins;
private InstanceDemo() {
}
public InstanceDemo getInstance(){
return ins==null? new InstanceDemo(): ins;
}
}
