While Using Apache HttpClient library to make Http requests, we should always release connection immediately after completion of the operation. For making HttpRequest Apache HttpClient library provides CloseableHttpClient and CloseableHttpResponse classes which implements java closable interface. By calling the close method of a closeable object in finally block we can close or dispose of connection…

Apache HttpClient library provides the ResponseHandler interface. By implementing ResponseHandler you can handle HTTP responses in a clean way. Using the response handler is the recommended way of executing HTTP requests and processing HTTP responses. This approach of handling response enables the caller to concentrate on the process of digesting HTTP responses and to delegate…

To format numbers, Java provides classes like NumberFormat and DecimalFormat classes. DecimalFormat is a concrete subclass of NumberFormat that formats decimal numbers. It has a variety of features designed to make it possible to parse and format numbers in any locale. All of these can be localized. Read more about DecimalFormat class on Oracle website.…

Java String class provides a method to split the string using a delimiter. It takes delimiter as a regular expression and Splits this string around matches of the given regular expression. This method has two overloaded versions. public String[] split(String regex, int limit) The array returned by this method contains each substring of this string that…

There are many classes in Java to generate random numbers. Random and ThreadLocalRandom are best to generate numbers between ranges. ThreadLocalRandom class Since Java 7, it provides ThreadLocalRandom class to generate random numbers. A random number generator isolated to the current thread. Like the global Random generator used by the Math class, a ThreadLocalRandom is…

Many time printing arrays in Java are required to logging and debugging purpose. In Java provides Arrays.toString(arr) or Arrays.deepToString(arr) for arrays within arrays (a nested array) to formatting simple arrays into printable strings. Example of printing a simple array: String names[] = new String[] {“ssp”,”anu”,”kirti”,”shaurya”}; System.out.println(names); System.out.println(Arrays.toString(names)); the output of above code is given below: [Ljava.lang.String;@2a139a55 [ssp, anu,…

ArrayIndexOutOfBoundsException is an exception, thrown to indicate that an array has been accessed with an illegal index. The index is either negative or greater than or equal to the size of the array. illegal index in java is index value less than zero or -ve values and index value equal to or greater than array…

In Java, strings are the reference type. So we can not compare two strings using the == operator as it compares references (will only return true when both references are of the same object). In Java, all objects are derived from class Object which has one method equals, which is used to compare equality of…

In Java NullPointerExceptions are exceptions that occur when we try to use a reference that points to no location in memory (Know as null) as though it were referencing an object (uninitialized objects or assigned to null object references). Calling a method or accessing a member on a null reference will throw a NullPointerException. Generally,…