JADEx (Java Advanced Development Extension) is a safety layer that runs on top of Java.
It currently supports up to Java 25 syntax and extends it with additional Null-Safety and Immutability features.
In the previous article, I introduced the Null-Safety features.
For more details, please refer to:
Introducing the New Immutability Feature
If Null-Safety eliminates runtime crashes caused by null,
Immutability reduces bugs caused by unintended state changes.
With v0.41 release, JADEx introduces Immutable by Default Mode
Core Concepts
The Immutability feature revolves around two simple additions:
apply immutability;
mutable
apply immutability;
-
When you declare this at the top of your source file:
- All fields
- All local variables (excluding method parameters)
- are treated as immutable by default.
-
When the JADEx compiler generates Java code:
- They are automatically declared as final.
mutable keyword
- Only variables declared with mutable remain changeable.
- Everything else (excluding method parameters) is immutable by default.
JADEx Source Code
package jadex.example;
apply immutability;
public class Immutability {
private int capacity = 2; // immutable
private String msg = "immutable"; // immutable
private int uninitializedCapacity; // uninitialaized immutable
private String uninitializedMsg; // uninitialaized immutable
private mutable String mutableMsg = "mutable"; // mutable
public static void main(String[] args) {
var immutable = new Immutability();
immutable.capacity = 10; //error
immutable.msg = "new immutable"; //error
immutable.mutableMsg = "changed mutable";
System.out.println("mutableMsg: " + immutable.mutableMsg);
System.out.println("capacity: " + immutable.capacity);
System.out.println("msg: " + immutable.msg);
}
}
Generated Java Code
package jadex.example;
//apply immutability;
public class Immutability {
private final int capacity = 2; // immutable
private final String msg = "immutable"; // immutable
private final int uninitializedCapacity; // uninitialaized immutable
private final String uninitializedMsg; // uninitialaized immutable
private String mutableMsg = "mutable"; // mutable
public static void main(String[] args) {
final var immutable = new Immutability();
immutable.capacity = 10; //error
immutable.msg = "new immutable"; //error
immutable.mutableMsg = "changed mutable";
System.out.println("mutableMsg: " + immutable.mutableMsg);
System.out.println("capacity: " + immutable.capacity);
System.out.println("msg: " + immutable.msg);
}
}
This feature is available starting from JADEx v0.41. Since the IntelliJ Plugin for JADEx v0.41 has not yet been published on the JetBrains Marketplace, if you wish to try it, please download the JADEx IntelliJ Plugin from the link below and install it manually.
We highly welcome your feedback on the newly added Immutability feature.
Finally, your support is a great help in keeping this project alive and thriving.
Thank you.
