Java Long - getLong() Method

The java.lang.Long.getLong() method is used to determine the long value of the system property with the specified name. The first argument is treated as the name of a system property.

If there is no property with the specified name, if the specified name is empty or null, or if the property does not have the correct numeric format, then null is returned.

Syntax

public static Long getLong(String nm)

Parameters

Return Value

Returns the Long value of the property.

Exception

Throws SecurityException, for the same reasons as System.getProperty.

Example:

In the example below, the java.lang.Long.getLong() method returns the Long value of the system property with the given name.

import java.lang.*;

public class MyClass {
  public static void main(String[] args) {
    
    //creating system property using setProperty
    String x = "285";
    System.setProperty(x, "285");
    String y = "abc";
    System.setProperty(y, "abc");

    //printing the Long value of x
    System.out.print("The Long value of x is: "); 
    System.out.println(Long.getLong(x));

    //printing the Long value of y 
    System.out.print("The Long value of y is: "); 
    System.out.println(Long.getLong(y));
  }
}

The output of the above code will be:

The Long value of x is: 285
The Long value of y is: null