Which one is Better Vector or SynchronizedList

-
Vector and SynchronizedList are synchronized.

In case of vector the synchronization is at method level,

Example:

public synchronized E get(int index) {
return (E)elementData[index];
}

And in case of SynchronizedList, the statements within the methods are synchronized on the list object.
SynchronizedList is static inner class inside collections class which implements list interface and necessary methods using synchronized blocks like below.

Link to Source code

Example :

public E get(int index) {
synchronized(colobj) {return list.get(index);}
}
where colobj is the collection object.

When you do Collections.synchronizedList(new ArrayList()); you end up creating 2 instances of List. Whereas, in case of Vector, you are creating only one instance.



Popular posts from this blog

What's New in JAVA 8

-
Finally Java 8 released under oracle leadership with many features and enhancements. Though some of the popular JSR's like JSR 294 (Jigsaw) are deferred again to next release, Java 8 still be the largest ever upgrade to java after it was introduced in 1996.  Lets see one of those improvements.  Performance improvement of java.util.HashMap under high hash-collision conditions : Just to give a little background : HashMap is used to store key-value pairs in no.of buckets technically 'Entry' objects . Entry is an inner class of HashMap. Please click  here to see the source code in java 7. Each bucket has a unique number called hash code. When you try to put a key-value pair into the map, the hashmap will look at the hash code of the key, and store the pair in the bucket of which the identifier is the hash code of the key. Let's say if hash code of two keys are same then hash-collision occurs. Till now (prior to Java 8), hash collision is addressed by creati
Read more

Singleton Design Pattern

-
We need to create a class which can have only one instance at any time. Solution 1: public class MySingleton { private static MySingleton singleton= new MySingleton(); private MySingleton(){ System.out.println( "Object Created" ); } public static MySingleton getMySingleton(){ return singleton; } } Let's create the object when we need it, not at the time of loading the class. Solution 2(with Lazy loading): public class MySingleton { // Line : 1 private static MySingleton singleton=null; // Line : 2 private MySingleton(){ System.out.println( "Object Created" ); } // Line : 3 public static MySingleton getMySingleton(){ // Line : 4 if(singleton == null) // Line : 5 { singleton = new MySingleton();
Read more

Internals of JSF

-
Once jsf project set up properly i.e entries in the web.xml,jsf related jars in lib folder of your web app( setting up jsf project ) we have to create a faces-config.xml to make our set up into a full fledged jsf application. Creating Faces-config.xml :: In the name itself telling us that it contains all the configurations needed for all jsf pages.In fact we don't need to create the file with the same name.We can create it with any name and we have to mention same as a context parameter in the WEB.xml ( setting up jsf project ).Now its the time to jump into the detailed view.   Fallowing are the two main components that we use frequently. 1)Managed Beans It represents a Java bean that will be instantiated dynamically at the run time by JSF container.We can achive inversion of control in JSF. Ex: Class User{ private String name; private String Address; //setters and getters for both properties } Declaration in faces-config.xml   <man
Read more