Articles

Java Hashtable, HashMap, ConcurrentHashMap: Performance Impact

,

There are a good number of articles that articulate functional differences between HashMap, Hashtable, and ConcurrentHashMap. This post compares the performance behavior of these data structures through practical examples. If you don’t have the patience to read the entire post, here is the bottom line: when you are confronted with the decision of whether to use HashMap, Hashtable, or ConcurrentHashMap, consider using ConcurrentHashMap since it’s thread-safe implementation without compromise in performance.

Performance Study

 To study the performance characteristics, I have put together this sample program:

Source de l’article sur DZONE

/par

Coordinating Threads Using CountDownLatch

,

Since Java 5, the core Java APIs have been enhanced with more features for handling coordination between threads in concurrent programming. In this post, we discuss a class in the java.util.concurrent package that aids in this purpose: the CountDownLatch.

Introduction

The CountDownLatch class enables us to coordinate threads by introducing awareness of the number of threads that are carrying out related tasks and keeping track of the number of threads that have completed their task. 

Source de l’article sur DZONE

/par

The Performance Impact of java.lang.System.getProperty()

,

‘java.lang.System.getProperty()’ is a common API used by Java developers to read the System properties that are configured during application startup time. i.e. when you pass “-DappName=buggyApp” as your application’s startup JVM argument, the value of the ‘appName’ system property can be read by invoking the ‘java.lang.System.getProperty()’. Example:

Java

  

public static String getAppName() { String app = System.getProperty("appName");   return app;
}

Source de l’article sur DZONE

/par

Large or Small Heap Size? [Video]

,

Do you want to run your application with a large heap size or a small heap size? What is the right strategy? Which strategy is more expensive? Which is more performant? Watch this video to know more!

Source de l’article sur DZONE

/par