java super和this关键字,super是访问父类,this是访问当前类
class A { public void eat1() { System.out.println("爸爸在吃"); } } class B extends A { public void eat2() { System.out.println("儿子在吃"); } public void eat(int who) { if (who == 1) { this.eat2(); } else { super.eat1(); } } }
public class test { public static void main(String[] args) { &...
java一个类可以有多个构造方法,根据传参类型和个数来匹配执行哪个构造方法。public class Member { public Member(){  ...
java限制1个方法同一时间只能被一个线程访问public synchronized void setOrderPay(){ }加上synchronized 修饰符即可...
java stringBuffer(1).stringBuffer和stringBuilder区别stringBuffer是线程安全的,stringBuilder速度更快(2).简单的stringBuffer例子StringBuffer sBuffer = new&nb...
(1).创建数组double[] myList = new double[size]; //推荐创建方式 double myList[] = new double[size];  ...
(1).java睡眠函数Thread.sleep(时间); //单位为毫秒(2).java睡眠函数例子Date dNow = new Date(); SimpleDateFormat ft = new&nbs...