读取每一个key并放入map private void readObject(java.io.ObjectInputStream s)throws java.io.IOException, ClassNotFoundException {// Read in any hidden serialization magics.defaultReadObject();// Read capacity and verify non-negative.int capacity = s.readInt();if (capacity < 0) {throw new Inval...
}// java.io.Serializable的读取函数// 将HashSet的“总的容量,加载因子,实际容量,所有的元素”依次读出privatevoidreadObject(java.io.ObjectInputStream s)throwsjava.io.IOException, ClassNotFoundException {// Read in any hidden serialization magics.defaultReadObject();// Read in HashMap capacity and load...
HashSet不保证输出的顺序。 例:2.1.1 import java.util.*; public class TestMark_to_win { public static void main(String args[]) { HashSet h = new HashSet(); h.add("1"); h.add("2"); h.add("3"); h.add("4"); System.out.println(h); } }...
Object> map;//底层使用HashMap来保存所有元素,确切说存储在map的key中,并使用transient关键字修饰,防止被序列化//Dummy value to associate with an Object in the backing Map//privatestaticfinalObject PRESENT =newObject();//常量,构造一个虚拟的对象PRESENT,默认为map的value值(HashSet中只需要用到键,而...
更不能保证自然顺序（a-z）下面是《Thinking in Java》中的使用Integer对象的HashSet的示例importjava....
Java集合之HashSet HashSet是一个没有重复元素的集合,HashSet是由HashMap实现的,不保证元素的顺序,并且HashSet允许使用null元素。HashSet不是线程安全的,当多个线程同时访问HashSet时,会出现问题,解决的方法是通过对自然封装该Set的对象执行同步操作来完成的。还可以使用Collections.synchronizedSet方法来包装set。
对于HashSet而言,它是基于HashMap实现的。HashSet底层采用HashMap来保存元素,因此HashSet底层其实比较简单。
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Methods declared in interface java.util.Set addAll,containsAll,equals,hashCode,removeAll,retainAll,toArray,toArray Constructor Detail HashSet public HashSet() Constructs a new, empty set; the backingHashMapinstance has default initial capacity (16) and load factor (0.75). ...
1. 概述 Hash table and linked list implementation of the Set interface, with predictable iteration order. This implementation differs from HashSet in that it maintains a doubly-linked list running t…