Yogesh's Tech Blog

In previous example I have explained using enum using color constants. Java util collection has provides EnumSet , it is a specialized Set implementation for use with enum types. In this post I have explained usage of EnumSet using an example. A text can have multiple attributes like bold, italic, underlined etc. Given a text can have these properties, defined a sample Text class with bit fields as text properties public class Text { //defining Text properties using int public static final int BOLD = 1<<0; public static final int ITALIC = 1<<1; public static final int UNDERLINED = 1<<2; private int style; public Text( int style){ this .style = style; } public boolean isBold(){ return (BOLD&style)==BOLD; } public boolean isItalic(){ return (ITALIC&style)==ITALIC; } public boolean isUnderlined(){ return (UNDE...

As part of Generics , Java language supports type safe programming. It allows a type or method to operate on objects of various types while providing compile-time type safety. The most common use case is while using Java Collection framework. For example if you define a list of string and trying to add integer value to the list, compiler throws error. List list = new ArrayList(); //Compilation Error : he method add(int, String) in the type List is not applicable for the arguments (int) list.add(10); As a developer you may always notice redundancy in defining parameter type information in both the side of declaration. As off Java 1.6, language doesn’t provide any feature to overcome it. Using Static Factory : One possible way to overcome this problem by using static factory methods. If you frequently use typed list or map in application then you can define generic static factory methods which returns you required typed map or list. public static HashMap getMapInstance(){ ...

Java 7 has improved the exception handling by ease of development, reduced code duplication  and intelligent throws clause. 1. More than one  exception types in single catch block: Java 7 onwards single catch block can handle multiple exception types. Now Catch block can specify ‘|’ separated exception types instead of only one exception. It prevent code duplication in case when same operation has to perform for all of set of types of exceptions and improve code readability. Old style : try { //your code here } catch (IOException ex) { log(ex); throw ex; catch (SQLException ex) { log(ex); throw ex; } New style : try { //your code here } catch (IOException|SQLException ex) { logger.log(ex); throw ex; } 2. Intelligent throws clause : Method declaration has to include the list of exception its is going to throws using throws clause. These exception types has to be matched with catch block throw statement. Java 7 onwards compiler ...