SEARCH KEYWORD -- Pure Java


  Why accessing Java HashMap may cause infinite loop in concurrent environment

HashMap in Java is frequently used to handle key/value pairs. But it is not a good candidate to be used in concurrent environment where ConcurrentHashMap should be used instead. If used in concurrent environment, it may cause lots of unexpected behavior even including make the program getting into an infinite loop situation. To understand how this can happen, let's first discuss how HaspMap works internally. In this post we will use implementation of HashMap before Java 8 as example, Java 8 prov...

   JAVA,HASHMAP,INFINITE LOOP     2020-03-29 01:47:00

  TIOBE : What's the future of C#?

TIOBE released the programming language index for August 2012, the top 3 programming languages are still C, Java and Objective-C. Objective-C still performs well after it ranked 3rd place last month, it's still rising. Is there any possibilty Object-C will overtake Java in the near future? However, Microsoft's C# doesn't look so good. C# is generally recognized as the enterprise language with most modern and expressive features available today and C# has shown more downward trends in the past an...

   TIOBE,August,C#     2012-08-13 14:48:11

  Maybe we need //Comment comment

Do we need comment in our programs? Depends, if we can write a program which can clearly tell s the reader what the program does, then we had better to avoid unnecessary comments. However, if the program we develop is complex enough and it involves some uncommon logic which needs more explanation, then we have to add comment and make sure the comment we add can correctly tell the readers what we do. The worst scenarios is not you forget or you don't want to add comment, it's that you add comment...

   comment,programming     2014-07-23 04:38:04

  Deep Understanding of ReentrantLock: Unlocking the Mysteries of Java Concurrent Programming

ReentrantLock introduction ReentrantLock is a class in the Java concurrent package, java.util.concurrent.locks, and is an implementation of the Lock interface. As its name suggests, it is a reentrant mutual exclusion lock. A mutual exclusion lock is a synchronization tool used to protect shared resources, ensuring that only one thread can access the resource at a given time. Reentrant means that a thread can acquire the same lock multiple times without causing a deadlock. This lock provides some...

   JAVA,REENTRANTLOCK,CONCURRENCY,MULTITHREADING     2023-05-22 08:01:13

  Java Interview Questions

Currently there are many articles online which summarize the list of Java interview questions. Some cover lots of basic questions and some cover some specific questions in specific area such as multithreading. In this post, we will not cover the really basic questions, we will cover something different. For basic question, you can read Java Interview Questions。 Basic What is primitive data type? How many primitive data types in Java? What are they? -- A primitive type is prede...

   JAVA,SECURITY,INTERVIEW,CAREER,MULTITHREADING,QUESTION,JAVA INTERVIEW,JAVA CORE     2019-01-21 07:07:08

  TIOBE : Objective-C overtakes C++

TIOBE recently released the programming community index for July. From the index,we can find that the biggest change is that Objective-C overtakes C++ as the 3rd most popular language among programmers. Because of the popularity of iPhone and iPad, Objective-C is used by more and more mobile developers who want to develop apps for Apple products. Also, many developers are willing to develop apps for Apple since they can gain more profit on Apple platform than on Android platform.C++ is mainly us...

   TIOBE,July,C++,Objective-C,overtake     2012-07-05 22:49:49

  TIOBE : Where is that next big programming language?

TIOBE has released the Programming Community Index for May 2012 a bit late. The top 3 languages do not change compared to last Month TIOBE : C overtakes Java as the No.1 programming language, they are still C,Java and C++. However, the share of Java is continuing dropping, Objective-C is steadily rising  Other languages which have rising trend are Visual Basic.NET，PL/SQL and Logo.The last 8 years not much has changed in the top 10 of the TIOBE index except for Objective-C (in) and Del...

   TIOBE,2012,May,King     2012-05-12 01:18:27

  3 meanings of Stack

We may frequently see stack when we read programming books. But many times we may be confused about the different meanings of it. This term actually has three common meanings. Here we explain the three different meanings of Stack in programming. 1. Data structure The first meaning of Stack defines a method for storing data. Its feature is LIFO9Last In First Out). In this data structure, data are accumulated level by level. The data last put in is added at the top of the stack. When using the dat...

   Stack,Memory,Data structure     2014-02-24 04:56:46

  Introduction to DTLS(Datagram Transport Layer Security)

Secure communication has become a vital requirement on the Internet. Lots of information transferred through the Internet are sensitive data such as financial transactions, medical information, media streaming etc. To ensure security of data transferred on the Internet, a few secure protocols have been designed including SSL/TLS and IPsec. Many large websites in the world have adopted TLS. Apart from SSL/TLS, there is some other protocol designed to be used in special cases. One of them is ...

   JAVA 9,DTLS,TLS,SECURITY     2016-04-02 05:55:36

  Select top 3 values from each group in a table with SQL

Yesterday, my friend Liu Bing asked me a question about how to select top 3 values for each person in a database table using SQL. I think this question is interesting and it deserves some thoughts. Here I record down how to solve this issue. Assume we have a table which has two columns, one column contains the names of some people and the other column contains some values related to each person. One person can have more than one value. Each value has a numeric type. The question is we want to se...

   SQL,Correlated query,top 3     2013-05-23 03:21:25

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