工厂模式
序言
工厂模式在《Java与模式》中分为三类:
简单工厂模式(Simple Factory):不利于产生系列产品;
工厂方法模式(Factory Method):又称为多形性工厂;
抽象工厂模式(Abstract Factory):又称为工具箱,产生产品族,但不利于产生新的产品;
You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.
You may assume the two numbers do not contain any leading zero, except the number 0 itself.
多线程下,一个对象会被多个线程共享,存在多线程并发地修改对象的属性,需要做些同步访问控制,
如显示锁,CAS操作,会带来额外的开销和问题,如上下文切换、等待时间、ABA问题。Immutable Object
模式意图通过使用对外可见的状态不可变的对象,使得天生具有线程安全性。
term query
查询的是词项<分词后的> (eg:Java编程思想) Java编程 term query 不能查到 分词后变成(Java 编程 思想) matchQuery能查到
分词器
,满足两个条件才能被搜到:Given an array of integers, return indices of the two numbers such that they add up to a specific target.
You may assume that each input would have exactly one solution, and you may not use the same element twice.
Example:
Given nums = [2, 7, 11, 15], target = 9,
Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1].