A Java application can accept any number of arguments from the command line. This allows the user to specify configuration information when the application is launched.
Interactive Console Applications in Java Learn how to make your applications pay more attention to what users are telling them. Many Java libraries for parsing command-line arguments exist. Executing a jar in Command Line. When compile in an executable java jar you can simply execute it from the command line. Java -jar mon-exec.jar In order to send some parameters: java -jar mon-exec.jar aStringParameter In this example the string “aStringParameter” is sent to the variable “args” in the Main class.
- Java is one of the most commonly used programming languages. It is also an IDE-intensive programming language, with tight integration with Eclipse. If you are just starting out learning Java, here is a basic guide to help you start running the Java application from the command prompt (in Windows.
- Java console example. The following example creates a Java console application which reads data from a CSV file and computes some basic statistics.
- Jul 27, 2016 This project is built on Java 8, in Spring Tool Suite (an Eclipse derivative), and uses Gradle and Maven to build and install dependencies. In addition, Gradle is using the 'Application' plugin, which allows us to build and run the command line java application with one simple Gradle command.
The user enters command-line arguments when invoking the application and specifies them after the name of the class to be run. For example, suppose a Java application called
Sort
sorts lines in a file. To sort the data in a file named friends.txt
, a user would enter:When an application is launched, the runtime system passes the command-line arguments to the application's main method via an array of
String
s. In the previous example, the command-line arguments passed to the Sort
application in an array that contains a single String
: 'friends.txt'
.Echoing Command-Line Arguments
The
Echo
example displays each of its command-line arguments on a line by itself:The following example shows how a user might run
Echo
. User input is in italics. Free realtek sound driver download.Note that the application displays each word —
Drink
, Hot
, and Java
— on a line by itself. This is because the space character separates command-line arguments. To have Drink
, Hot
, and Java
interpreted as a single argument, the user would join them by enclosing them within quotation marks.Parsing Numeric Command-Line Arguments
Java Command Line Install
If an application needs to support a numeric command-line argument, it must convert a
String
argument that represents a number, such as '34', to a numeric value. Here is a code snippet that converts a command-line argument to an int
:parseInt
throws a NumberFormatException
if the format of args[0]
isn't valid. All of the Number
classes — Integer
, Float
, Double
, and so on — have parseXXX
methods that convert a String
representing a number to an object of their type.