SEARCH KEYWORD -- ORACLE


  Java SynchronizedList and Iterator

While reading some material about concurrency, I come up with some writing about using SynchronizedList wrap about normal List to enable synchronization.   But one interesting thing is http://docs.oracle.com/javase/7/docs/api/java/util/Collections.html#synchronizedList%28java.util.List%29   It says     It is imperative that the user manually synchronize on the returned list when iterating over it:     1   List list = Collections.synchronizedList(new A...

       2015-12-03 03:04:08

  Hexadecimal and long in Java

Today I encountered a hexadecimal operation problem when I was implementing a bit reverse function for integer type. Basically in the implementation, there is an operation which is to do the bit operation & between one long integer and a hexadecimal number 0x00000000FFFFFFFFF. I was expecting that the high 32 bits of the long integer will be zeroed. But unfortunately I didn't get the expected result. The basic implementation is: long num=0x00F0_0000; num = (num>>16) | (num<<16); ...

   Hexadecimal,long,Java,bitwise operation     2014-06-18 23:44:32

  ConcurrentHashMap vs Collections.synchronizedMap()

ConcurrentHashMap and Collections.synchronizedMap() both provide thread-safe operations of collections of data. They are used in multithreaded programs to provide both thread safety and performance improvements. In many cases, we can use either of them. But the realization of thread safety is different for these two implementations. ConcurrentHashMap will create an HashEntry[] array internally to store the elements passed in from a Map, while Collections.synchronizedMap() will return a Synchroni...

   ConcurrentHashMap,Collections.synchronizedMap     2014-09-18 05:04:59

  Different types of keystore in Java -- Overview

Keystore is a storage facility to store cryptographic keys and certificates. They are most frequently used in SSL communications to prove the identity of servers and clients. A keystore can be a file or a hardware device. Three are three kinds of entries can be stored in a keystore depending on the types of keystores. The three types of entries are: PrivateKey : This is a type of keys which are used in asymmetric cryptography. It is usually protected with password because of its sensitivity. It ...

   JAVA,KEYSTORE,OVERVIEW,JKS,PKCS12,JCEKS,PKCS11,DKS,BKS     2014-08-18 02:09:54

  The latest on Java-on-Java: the Oracle experiment that is gaining momentum

What is Project Metropolis? The not so hush-hush Project Metropolis is all set to implement Java on itself – popularly known in the developer community as Java-on-Java. Oracle has released updates on its progress, and they are very encouraging. The project will focus on building a JIT (just in time) compiler that is written in Java. It is being touted as the experimental clone of JDK (Java Development Kit) 10.  Work on ‘ahead of time’ compiling and Graal compiler is also i...

   HIRE JAVA DEVELOPERS     2017-05-22 08:49:32

  Different types of keystore in Java -- DKS

Domain KeyStore(DKS) is a keystore of keystore. It abstracts a collection of keystores that are presented as a single logical keystore. Itself is actually not a keystore. This new keystore type is introduced in Java 8. There is a new class DomainLoadStoreParameter which closely relates to DKS. To load different keystores into the single logical keystore, some configuration is needed. Here is the format of the configuration for grouping different keystores. domain [ ...] { keystore [ ....

   Java,keystore,DKS,tutorial     2015-01-20 02:27:27

  try { return } finally {}

Do you know what value will be printed when following program is ran? class Test { public int aaa() { int x = 1; try { return ++x; } catch (Exception e) { } finally { ++x; } return x; } public static void main(String[] args) { Test t = new Test(); int y = t.aaa(); System.out.println(y); } } And before answering the above question, do you have answers to following questions? If ther...

   JAVA,JAVA INTERVIEW QUESTION     2016-09-26 08:06:28

  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

  Oracle CEO Mark Hurd : IBM PureSystem is far behind Oracle

Oracle CEO Mark Hurd had an interview with Chinese media in San Francisco on 19th April. Mark Hurd first introduced different levels of Oracle's overall strategy: 1) the product must achieve best among similar products; 2) system open, vertical integration to provide customers with maximum performance; 3) Industry specific solutions; 4) give users the right to choose and the integration of the cloud environment (private cloud, public cloud, mixed cloud). In addition, Mark Hurd share his own...

   Oracle,IBM,Pureystem,Hardware/Software     2012-04-19 07:17:24

  Java Then, Java Now - Looking at the evolution of Java from EE7 to EE9

Java, the programming language developed at Sun Microsystems in the 90s and later acquired by Oracle, is the most common programming environment used today, by developers across the globe. With the diversification of applicability that accompanied the technological boom, Java updates now come as Standard Editions (SE), Enterprise Edition (EE) and Micro Edition (ME). The Java SE contains the core programming logic and platform, used for relatively smaller-scale tasks and academic purposes. Java E...

   JAVA DEVELOPMENT COMPANY     2017-07-05 01:09:28

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