迭代对于我们搞Java的来说绝对不陌生。我们常常使用JDK提供的迭代接口进行Java集合的迭代。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 Iterator iterator=list.iterator();while(iterator.hasNext()){String string=iterator.next();//do something} 迭代其实我们可以简单地理解为遍历,是一个标准化遍历各类容...
Java中的Iterator是一种fail-fast的设计。 当Iterator迭代一个容器的时候,如果此时有别的方法在更改Collection(容器)的内容,那么Iterator就会抛出 ConcurrentModificationException 。正如官方文档中反复强调的: Thus, in the face of concurrent modification, the iterator fails quickly and cleanly, rather than risking ...
ListIterator<String> listIterator = items.listIterator(); while(listIterator.hasNext()) { String nextWithIndex = items.get(listIterator.nextIndex()); String next = listIterator.next(); if("REPLACE ME".equals(next)) { listIterator.set("REPLACED"); } } listIterator.add("NEW"); while(lis...
An iterator over a collection.Iteratortakes the place ofEnumerationin the Java Collections Framework. Iterators differ from enumerations in two ways: Iterators allow the caller to remove elements from the underlying collection during the iteration with well-defined semantics. ...
在Java中,有很多的数据容器,对于这些的操作有很多的共性。Java采用了迭代器来为各种容器提供了公共的操作接口。这样使得对容器的遍历操作与其具体的底层实现相隔离,达到解耦的效果。 在Iterator接口中定义了三个方法: 2、迭代器使用 publicstaticvoidmain(String[] args) ...
1、Iterator迭代器:(1)类型转换异常:ClassCastException;集合中存放的是多个对象时,在强转时会出现; 会出现以下异常: (2)添加泛型避免异常;在编译时期出现编译失败; 与上面对比: 效果如下: 当添加元素时:The method add(String) in the t
("Charlie");students.add("David");}publicvoiddisplayStudents(){Iterator<String>iterator=students.iterator();System.out.println("Students in the list:");while(iterator.hasNext()){System.out.println(iterator.next());}}publicstaticvoidmain(String[]args){StudentListlist=newStudentList();list....
public String toString(){ return "Frequency="+this.frequency+", Type="+this.TYPE; } } Channel is a simple POJO class that has attributes frequency and channel type.ChannelCollection.java package com.journaldev.design.iterator; public interface ChannelCollection { ...
Finally, we create two threads that process both halves of the list and print each element. Note that both threads run concurrently, processing their respective halves of the list in parallel. List<String>bigList=Stream.generate(()->"Hello").limit(30000).toList();Spliterator<String>split=big...
这个接口使用了java的泛型变成,next方法会返回一个参数化的元素。 如果next方法在容器中没有元素 再被调用,会报一个NoSuchElementException的错。所以我们需要hasNext方法来帮忙做预判。一个典型的使用代码块如下: while(iter.hasNext()){Stringvalue=iter.next();System,out.println(value);} ...