// primarily by name, secondarily by value; null-safe; case-insensitive public int compareTo(Metadata other) { if (this.name == null && other.name != null){ return -1; } else if (this.name != null && other.name == null){ return 1; } else if (this.name != null && other.n...
4. Making Created Collection Streams Null-Safe 4.1. Add Checks to PreventNullDereferences To prevent unintendednullpointer exceptions,we can opt to add checks to preventnullreferenceswhen creating streams from collections: Stream<String> collectionAsStream(Collection<String> collection) { return collection...
String author = "Author"; String book = "book"; String duplicateBook = "BOOK"; assertThat(author.compareToIgnoreCase(book)) .isEqualTo(-1); assertThat(book.compareToIgnoreCase(author)) .isEqualTo(1); assertThat(duplicateBook.compareToIgnoreCase(book)) .isEqualTo(0); 3.StringComparison WithO...
CompareTo(StringBuffer) Compares two StringBuffer instances lexicographically. Delete(Int32, Int32) Added in 1. DeleteCharAt(Int32) Added in 1. Dispose() (Inherited from Object) Dispose(Boolean) (Inherited from Object) EnsureCapacity(Int32) Ensures that this object has a minimum capacity av...
keyComparator- theComparatorused to compare the sort key Returns: a comparator that compares by an extracted key using the specifiedComparator Throws: NullPointerException- if either argument is null Since: 1.8 comparing static <T,U extendsComparable<? super U>>Comparator<T> comparing(Function<?
compare和自定义的compare 6、Map集合 HashMap、HashTable、ConccurentHashMap的区别? HashMap:(Java8以前):数组+链表,非synchronized,速度快。 (Java8后):数组+链表+红黑树 某个桶上高于8,则转为红黑树,小于6则转为链表。 HashMap在使用的时候,才会被初始化。
String city=null;if(student!=null){Address address=student.getAddress();if(address!=null){City city=address.getCity();if(city!=null){String cityCode=city.getCode();}}} groovy语言的安全导航操作符(The Safe Navigation operator) groovy语言提供了安全导航符操作符。
implementation'org.apache.commons:commons-lang3:3.9' Conclusion That's folks for comparing strings in Java. We discussed 4 different ways to compare two strings with each other. You should always useObjects.equals()as it is null-safe and performs better. ...
在JDK 1.8 中,ConcurrentHashMap 借鉴了 HashMap 的数据结构,采用数组 + 链表 + 红黑树,并且使用 CAS(Compare and Swap)操作和 synchronized 关键字来保证线程安全。 读操作大多时候不需要加锁,从而大大提高了并发性能。 import java.util.concurrent.ConcurrentHashMap; public class ConcurrentHashMapExample { <!
Unchecked Exception ：运行时异常，是RuntimeException类及其子类，如：NullPointerException(空指针异常)、...