JarCastingutil
Table of Content
- Usage
- Wrappers
- Simple
- Complex
- Limits
- Other Stuff
Usage
Add the following Maven dependency
<dependency>
<groupId>se.eris</groupId>
<artifactId>jtype</artifactId>
<version>0.4.1</version>
</dependency>
Simple Wrappers
The most simple usage is to just extend a Wrapper class. The wrapper classes implement the hashCode, equals, and toString methods.
public class Description extends StringWrapper {
public Description(final String description) {
super(description);
}
}
Complex Wrappers
- DyadWrapper
- PairWrapper
- OneOfWrapper
- ...
Limits
To get some use out of the library you can combine it with a Limit. In this example the description String is limited to max 1000 characters.
public class Description extends StringWrapper {
public static final int MAX_LENGTH = 1000;
private static final LimitedString LIMITED_STRING = LimitedString.init()
.length(MAX_LENGTH).build();
public Description(final String description) {
super(LIMITED_STRING.of(description));
}
}
If no predefined limit matches your requirements you can create your own Limits easily:
Limit<Integer> evenLimit = (item) -> (((item % 2) == 0) ? Optional.empty() : Optional.of(ValidationError.of(item + " is odd")));
LimitedInteger even = LimitedInteger.init().limit(evenLimit).build();
int a = even.of(2); // a = 2;
int b = even.of(17); // throws ValidationException
Other Stuff
SOptional
A Serializable Optional until the JCP realizes the mistake and makes Optional serializable. It also takes some useful methods from the Guava Optional.