Java Command Annotations – @Range
Java command annotations are used for the developing Java commands in PAK.
This chapter describes the functionality of the @Range annotation.
It also gives two examples how you can use this annotation in your implementation.
1. Basics
The @Range annotation restricts the values that can be set to a command variable.
It only works together with the @Persistent annotation and is only applicable to
variables of a primitive number type. This annotation is evaluated at runtime and raises an exception at the
latest.
This annotation does only work in combination with the @Persistent annotation.
|
2. Properties
There are two properties defined for the @Range annotation: lowerLimit and upperLimit.
Both properties are of type Number and represent the lower and the upper limit of a range.
Allowed values for each limit are real numbers as well integers as decimals.
It is possible to set both or just one of the values to use the @Range annotation.
So the @Range annotation can be used to define a minimum or maximum too.
Setting no value for @Range is possible but not recommended as the range will be the maximumrepresentable number by the datatype. |
3. Usage
In the following examples are given on how to use the @Range annotation.
The first example shows how both properties are defined to set a lower and upper limit. The annotated field
can be equal to 0 or 100 and between the two limits but not greater than 100 or lesser than 0.
@Range annotation as range/**
* @workflowDocu This command does something with numbers.
*/
@JavaCommand
@CommandGroup("Numbers")
public class somethingWithNumbers {
[...]
/**
* @workflowDocu Example with a range between 0.0 and 100.0
*/
@Range(lowerLimit = 0.0, upperLimit = 100.0)
@Persistent
private double percentageShare;
[...]
}In the second example only the lower range is defined with 0. In this case the annotated variable can be
equal to or greater but not lesser than 0.
@Range annotation as a minimum/**
* @workflowDocu This command does something with numbers.
*/
@JavaCommand
@CommandGroup("Numbers")
public class somethingWithNumbers {
[...]
/**
* @workflowDocu Example with 0 as minimum
*/
@Range(lowerLimit = 0)
@Persistent
private double positiveNumber;
[...]
}