Java Spring Command Line Parameters
Posted on May 6, 2024 (Last modified on September 27, 2024) • 2 min read • 404 wordsVideo is in Swedish
When building command-line applications with Java Spring, it’s essential to understand how to effectively use command line parameters to configure and customize the application’s behavior. In this article, we’ll explore the basics of using command line parameters in Java Spring and provide a step-by-step guide on how to implement them.
Command line parameters, also known as CLI (Command-Line Interface) arguments or options, allow users to pass additional information to an application when it’s launched. These parameters can be used to customize the behavior of the application, specify input files, or provide configuration settings.
Java Spring provides built-in support for command line parameters through its CommandLineRunner
interface and the @Value
annotation. The CommandLineRunner
interface allows you to execute a method with a String[] args
parameter, which represents the command-line arguments passed to the application.
The @Value
annotation can be used to inject command line parameters into your Spring beans. For example:
@Service
public class MyService {
@Value("${my.param}")
private String myParam;
public void doSomething() {
System.out.println(myParam);
}
}
In this example, the @Value
annotation is used to inject a value from a property file or environment variable into the myParam
field.
The CommandLineRunner
interface can be implemented to execute a method with command-line arguments. For example:
@Component
public class MyRunner implements CommandLineRunner {
@Override
public void run(String... args) throws Exception {
System.out.println("Received command line arguments: " + Arrays.toString(args));
}
}
In this example, the run
method is called with an array of strings representing the command-line arguments.
When using command line parameters in Java Spring, follow these best practices:
In this article, we’ve explored the basics of using command line parameters in Java Spring. By understanding how to effectively use @Value
annotation and CommandLineRunner
interface, you can create robust and customizable command-line applications with Java Spring. Remember to follow best practices when implementing command line parameters to ensure a positive user experience.
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