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SEARCH KEYWORD -- JAVA CORE

  Address of a Java Object

In conventional java programming, you will never need address or location of a java object from memory. When you discuss about this in forums, the first question raised is why do you need to know the address of a java object? Its a valid question. But always, we reserve the right to experiment. Nothing is wrong in exploring uncharted areas.I thought of experimenting using a little known class from sun package. Unsafe is a class that belongs to sun.misc package. For some of you the package might ...

   Java,Object,Address,Memory,Start address     2011-09-29 11:17:46

  Different types of keystore in Java -- BKS

BKS is a keystore format provided by the popular third party Java cryptographic library provider -- BouncyCastle. It is a keystore similar to the JKS provided by Oracle JDK.  Before starting to use BKS, the BouncyCastle provider has to be downloaded and installed. To download the provider, please go to BouncyCastle download page. The provider can be installed by adding an entry in the java.security file. security.provider.N=org.bouncycastle.jce.provider.BouncyCastleProvider N means the pr...

   JAVA,KEYSTORE,BOUNCYCASTLE,BKS     2016-07-03 03:00:18

  Can API be copyrighted? At least Oracle hopes so

  The result of the lawsuit case war between Oracle and Google is clearer now. The court said that 9 lines of code of Android has violated intellectual property right, these 9 lines of code can be ignored relative to the number of codes for the whole Android system. But just like LinuxToy points out that the reasons why this case catches so much attention are : 1). The amount of money Oracle asked from Google is $1 billion; 2). The statement says Java language itself doesn't violate the int...

   Oracle,Google,API,Copyright,Lawsuit case     2012-05-11 00:47:58

  Use Memory Analyzer Tool in Eclipse

When developing applications, we often encounter memory issues of an application. To analyze how much memory each class takes, we need to have some specific tools to assist us. One of them is Memory Analyzer Tool on Eclipse. The Eclipse Memory Analyzer is a fast and feature-rich Java heap analyzer that helps you find memory leaks and reduce memory consumption. To use the Memory Analyzer Tool, you first need to install it on Eclipse. You can go to Help -> Install New Software.... Paste  h...

   Memory analyzer tool, Eclipse,heap dump, HPROF     2014-10-28 07:22:35

  Haxe: Another multiplatform language

There are two kinds of programmers: One is using different languages to solve problems, the other is inventing languages to solve problems. Haxe is an emerging open source programming language which is universal, powerful and easy-to-use. Some languages claimed they were multiplatform languages, such as Java, C# and ActionScript. They all are based on some platforms, Java has JVM, C# has .Net and ActionScript has Flash Player. While Haxe is a trule multiplatform language, it can be used to devel...

   Haxe,Multiplatform,Open source     2012-06-11 08:08:28

  Which web front-end framework to choose?

When doing web design, we often need to choose which front-end framework to use in order to provide great user experience and simplify the development. Also, compatibility problem can be solved by using front-end frameworks. Here is a list of front-end frameworks. Which one are you using? Which one do you prefer?1. Apache FlexApache Flex, is a software development kit for the development and deployment of cross-platform rich Internet applications based on the Adobe Flash platform. Initially deve...

   Web design,Front-end,Framework     2012-07-30 13:57:26

  Command Line Arguments

Our Hello program still isn’t very general. We can’t change the name we say hello to without editing and recompiling the source code. This may be fine for the programmers, but what if the secretaries want their computers to say Hello to them? (I know. This is a little far-fetched but bear with me. I’m making a point.)What we need is a way to change the name at runtime rather than at compile time. (Runtime is when we type java HelloRusty. Compile time is when w...

   Java,Command line arguments,First elemen     2011-09-30 11:31:54

  Fastjson just fixed a bug which might cause out of memory issue

Fastjson just fixed a bug which might cause service down a few days ago. This bug is caused by some mishandling of special character \x which is an escaped character to indicate hexdecimal number. The impact of this bug would be big if the attacker constructs a malicious data which would cause the service down.  The code which causes the issue is in com.alibaba.fastjson.parser.JSONLexerBase#scanString, when a JSON string is passed in, fastjson would parse the string character by c...

   FASTJSON,ALIBABA,BUG,NEWS     2019-09-07 06:03:49

  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

  Why 0.1+0.2 != 0.3

In programming languages such as JavaScript, c/c++, Java and Matlab, you will find that you will get unexpected result when doing float point calculation. For example, when calculating 0.1 + 0.1, you will not get 0.3: > 0.1 + 0.2 == 0.3 false > 0.1 + 0.2 0.30000000000000004 Don't be surprised of this result, this is the end result of IEEE 754 standard, float point number cannot be accurately represented according to IEEE 754 because: No enough memory is allocated for representing the num...

   float point,comparison,JavaScript     2014-11-19 05:32:46

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