This page is created by developers for all types of public which is based on the creation of small programming tutorials in JAVA, SQL, SPRING, Android, Phonegap, javascript, css, Maven. The main objective is to help with simple and specific problems that solve a given problem.
Below we present a brief introduction of JAVA and its evolutions.
JAVA is one of the most used programming languages, since it occupies a 20% of the market use, for this reason most of the tutorials are based on this language to generate technical contributions more efficient.
Evolution of its versions
1.0 In 1996 the language is born with this version where it contains classes, The JVM and AWT graphics.
1.1 In 1997 a restructuring was made in AWT events and Java Beans, JDBC, RMI.
1.2 In 1998 incorporates SWING Reflection adds strictfp reserved word and Collections.
1.3 In 2000 RMI changes to CORBA, and adds JNDI
1.4 In 2002 adds XML supported libraries with XSLT, regular expressions and assertions assert.
1.5 In 2004 he had a big jump because he included autoboxing which are the automatic conversions between primitive types (int to Integer).
adds enum and the improvement of the for loop.
1.6 In 2006 includes combination with other programming languages such as javascript, php, web services.
1.7 In 2011 the main change was in the garbage collector, better handling with date libraries.
1.8 In 2014 adds improvements in security measures and concurrency.
1.9 Scheduled for 2017.
Here's an explanation of 5 of the most commonly used classes in Java.
java.lang.String It is the class most used in Java because of its operations as well as processes, at some point in our process will have to work with string and this class is the one to handle that information, it should be noted that it is not the best option If it refers to concatenating strings it refers since its main characteristic is that it is not immutable, that is to say, that no value can be modified without another object being made in memory, a new object will be added in the string by the character string. Memory, for this operation is recommended StringBuilder that will allow us to concatenate strings for a better operation of our application. It has a series of methods that are of great help for all kinds of operations with characters, for example, having an array based on a split() character, index of the string based on an indexOf() character, etc.
java.util.ArrayList Class that its main function is to provide redimensible arrays that among its main features is that it implements all the operations of the lists (add, delete, add lists and remove lists), additional allows any type of elements, even null. They contain internal methods to manipulate the size of the array. An interesting fact is when you call your constructor ArrayList() creates an empty list with an initial capacity of 10 elements. Based on this explanation this class is very useful when you want to have an array of objects but the final size is not known.
java.util.HashMap Class that implements the Map interface and is very useful for storing data of different type according to its definition, additional allows to store null values as well as null keys, it is commonly used to save session data, multiple data for some process that requires different types of Settings.
java.util.Calendar Abstract class that provides methods to obtain the date in a specific time with its variables HOUR, DAY_OF_MONTH, YEAR, MONTH as well as manipulate the fields of the calendar, useful to obtain a particular day, this makes possible thanks to its different methods and its Variables. It is a good option to handle dates in the application because as it is mentioned that it is abstract it is not necessary to create a new object to have a date unlike the Date class.
java.io.File When you want to do operations with files, this is the class indicated since among its methods has the creation and deletion, additional has methods to know if it exists, if it is a directory, if it has files inside, if it is read only, the length , Rename it to another file, compare it with another, etc. In most applications it is necessary to do some type of operation with files, for this reason we place this class in the top 5.
Here the java tutorials.