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Overview of collections Collection in Java refers to a series of interfaces and classes for storing data, which can solve complex data storage problems. Guide: import java.util. *; The simplified set frame diagram is as follows: List. List ArrayList List is an interface: public interface List<E> extends Collection<E>{...} ArrayList ...

String class All string literals (such as "abc") in Java programs are examples of String Strings are constants (String objects are immutable, so they can be shared) The essence of a string is an array of characters: private final char value []; Common ways to create strings public class CreateString { public static void main(Strin ...

The review notes are based on the JavaSE notes of the 27 employment classes of the Intelligence Podcast. Link: Link: https://pan.baidu.com/s/1boDix6R Password: r1p6, I recommend that you don't read the new white, because it involves too many details, but it makes you easy to give up the path of Java. The new white recommends the following set ...

FutureTask can also be used as a latch.(FutureTask implements Future semantics and represents an abstract calculation of generatable results.The calculation represented by FutureTask is done through Callable, which is equivalent to a Runnable that generates results and can be in three states: Waiting to run, Running, and Completed.Execution Com ...

Usually, the way to implement the interface is to create his implementation class, so that his implementation class can implement the specific method in the interface. This paper will introduce another way to implement the interface: dynamic proxy mode to implement the interface. The steps of implementing the interface by dynamic proxy are as ...

Preface Hashtable in JDK is a K-V container of thread-safe. Its principle of thread-safe is very simple. It adds synchronized keyword to all methods involved in the operation of the hash table for locking operation. This achieves thread safety, but is very inefficient. //With synchronized acquisition of hashmap locks every time a method enters, ...

In JDK 1.8, the bottom layer of HashMap is stored in array Node < K, V > array. Each element in the array is stored in a linked list. When the element exceeds 8, the linked list is converted into a mangrove storage. red-black tree The red-black tree is essentially a balanced search Binary tree, which is used to store ordered data. Compare ...

I. Preface Dubbo's Extension Loader is an important component of "micro-kernel + plug-in" implementation, which is based on the java spi mechanism but provides the following extensions: jdk spi only obtains all implementations by interface class name, while Extension Loader obtains an implementation by interface class name and key ...

AspectJAware Advisor AutoProxy Creator and Analysis of Generating Agent Timing for Bean s As mentioned in the previous article, the class org. spring framework. aop. aspectj. autoproxy. AspectJAware Advisor AutoProxy Creator is the core class of AOP provided by Spring to developers. It is AspectJAware Advisor AutoProxy Creator that completes th ...

1. Preface Since everything in JAVA is an object, holding objects is particularly important. In JAVA, we can hold objects by creating a reference to them: 　　　　HoldingObject holding; You can also create an array of objects to hold a specific set of objects: 　　　　HoldingObject holding  = new HoldingObject[10]; However, an object reference ...