Programmer Group

ServerSocketChannelServer Socket Channel role? What do you do full-time?        1. Monitor the new TCP link channel.        2. Create a new Socket ChannelServer Socket Channel does not have any capabilities    Server Socket Channel does not have ...

Preface Through the introduction of the last Java Collection Series (1), readers must have mastered the basic concepts of collections. Next, the author will focus on the functions of each interface of collections and its common subclasses. Definition of Collecton Interface The Collection interface is defined as follows: public intefa ...

There is a noun around this chapter: Run-time Type Identification runtime type recognition Someone knows that the author introduced this concept from C++, but it doesn't matter. Understanding and concatenating this chapter is the most important thing The content of this chapter is actually for the type of information service, the main content i ...

I've written a brief version of ArrayList before, but now I'll go over a brief version of LinkedList (ps thinks that LinkedList in jdk source code has a lot of verbose and repetitive methods by looking at the source code). First, LinkedList implements a linked list. A linked list defined by this class can also be used like a stack or queue. ...

Start with this blog and slowly learn about Map collections together What is Map? Map is different from List. In List, we remember that it is mainly a linear list, which can be subdivided into Array List, Vector, and LinkedList. ) And the main thing is that List has only value, that is, only one value. In Map, it stores a combination of ke ...

Today, Deploy static resource packages come into our Production environment. Only static resource files, such as database connection information, SQL query statements, are involved in the package. After successful deployment, the following error occurred when starting the service: Exception in thread "main" java.lang.UnsupportedClassVersionErro ...

background Execute Java programs in the k8s docker environment, because we set the limit of cpu, memory, so the parameters of the JVM are not associated with the parameters we set when the Java program executes, resulting in the CPU and memory that the JVM perceives as the size of the CPU and memory on our k8s work node.The problem with this is ...

Due to the existence of GC auto-recycling mechanism in Java, the mechanism of reference counting is relatively perfect. Java divides the references of holding objects into strong references, soft references, weak references, virtual references in order of strength and weakness. Good use of references allows GC to quickly recycl ...

Most of the reference blogs are based on Hadoop 2.x and low-level java. The configuration process seems very simple to write. Looking at other people's blogs, it feels the same steps. But there are many problems when configuring the blog: data node can't start, the page can't display properly, data node inexplicably dies, resourcemanager can't ...

When writing programs or writing test papers, we always encounter classes or data structures defined by ourselves. If we put classes defined by ourselves into arrays such as List, sorting is very troublesome, such as: A Person class is defined below. class Person{ String name; int age; public Person(String name,int age) { t ...