Difference Between HashMap And Hashtable

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There are few differences between HashMap and Hashtable. This example illustrates the key differences with simple example. Hashtable is synchronized where as HashMap is not synchronized. It is one of the key difference between HashMap and HashTable. HashMap offers better performance than HashTable in the multi-threaded environments. Hashtable does not allow null keys or values. […]

Generic Constructors Example

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Generic is one of the useful language feature introduced from Java 5.0. There are many great features as part of the Generics is not fully utilized by the programmers. One such instance is the use of generic constructors. This example shows how to use the generic with constructor and takes the different type arguments. In […]

How To Load A Class Using Class.forName()

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This example shows how to load a class using the Class.forName() method. All the classes in your application or dependent class files are loaded by appropriate class loader prior to using in the application. By default, class files are loaded by JVM when first time accessed by the applications. However, in certain situations you have […]

Instance Initializer In Java

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In my previous example I have explained how to use static initializer in Java.This example shows how to use the instance initializer block in Java. The following are the few features of instance blocks. Instance initializers are block of code with out any keyword keyword. The code which needs to be initialized will be put […]

How To Get Class Loaded Path

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This example illustrates how to get the class loaded path. If you are aware of the java.lang.Class, it has methods for knowing the details of a class. There are many details this object can reveal us, one of the method defined in that class is Class.getProtectionDomain() which is useful for getting the source code path […]

How To Get Current Class Loader Name

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This example shows how to get the name of the class loader and parent class loader for the currently executing class. If you are not aware of the class loaders, please read our previous article about ClassLoader. What is the ClassLoader ? As its name implies, ClassLoader is a class that loads other classes. More […]

How To Get Implementing Interfaces Name For A Class

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This example illustrates how to get the implemented interfaces names of a particular class. If you are aware of the java.lang.Class, it has methods for knowing the details of a class. One of the method defined in that class is Class.getInterfaces() which is useful for getting all the interfaces names which it is implemented. This […]

How To Get Super Class Name From Object

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This example illustrates how to get the super class name from its instance. If you are aware of the java.lang.Class, it has methods for knowing the details of a class. One of the method defined in that class is Class.getSuperclass() which is useful for getting the super class’s java.lang.Class object. With that object, you can […]

How To Get Class Name From Object

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This example illustrates how to get the class name from its object. If you are aware of the java.lang.Class, it has methods for knowing the details of a class. One of the method defined in that class is Class.getName() which is useful for getting the name of the class. Note that, each instance has “class” […]

How To Resolve java.lang.IllegalAccessException

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This example shows when the java.lang.IllegalAccessException is thrown in your application. When an application tries to reflectively create an instance (other than an array), set or get a field, or invoke a method, if that method is not accessible to your application (probably the modifier is private or not accessible one), then your application will […]