JAVA编程思想学习笔记6-chap16-18-斗之气6段
2019-02-26 08:49 剑动情缥缈 阅读(224) 评论(0) 编辑 收藏 举报1.java.util.Arrays
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package com.chengjie; import java.util.Arrays; import java.util.List; public class TestArrays { public static void main(String[] args) { // int[] array1 = new int[10]; int[] array1 = { 1, 3, 5, 7, 9, 2, 4, 6, 8, 10}; Arrays.sort(array1); Arrays.parallelSort(array1); Arrays.parallelPrefix(array1, (left, right) ->{ // System.out.println(Arrays.toString(array1)); return left + right; }); System.out.println(Arrays.toString(array1)); System.out.println(Arrays.binarySearch(array1, 15)); Arrays.fill(array1, 5); int[] array2 = null; array2 = Arrays.copyOf(array1, 5); Arrays.fill(array2, 3); int[] array3 = Arrays.copyOfRange(array2, 0, 4); Arrays.setAll(array3, i -> i * 10); System.arraycopy(array1,0, array2, 0, 3); System.out.println(Arrays.toString(array2)); System.out.println(Arrays.toString(array3)); List<String> listString = Arrays.asList("hello", "world"); System.out.println(listString); } }
2.容器完整类库图
3.Set
- HashSet:特定顺序,需要实现hashCode()方法
- TreeSet:按照大小排序,需要实现Comparable接口
- LinkedHashSet:按照插入顺序保存元素,需要实现hashCode()方法
4.Map
- HashMap:需要实现①equals()方法-比较键②hashCode()方法-生成散列值
- 计算散列值--获取数组index---比较key---获取value
5.最佳实践:实现equals()的同时实现hashCode()
6.java.util.Collections
7.流
8.java.nio(non-blocking IO)非阻塞IO
- Buffers
- Channels
- Selectors