Release notes v2.4-j8

Supported Java

Built with Oracle JDK v 8.x. Should work with OpenJDK too.

The full release notes can be found here.

Migration from previous versions

There might be small changes when you upgrade to v 2.4

Validation package moved

This package: org.javalite.activejdbc.validation was renamed org.javalite.validation and moved to dependency javalite-common. Your imports need to change from:

import org.javalite.activejdbc.validation.ValidationException;

to:

import org.javalite.validation.ValidationException;

Conversion package moved

Conversion package moved to dependency javalite-common and is renamed: Old example:

import org.javalite.activejdbc.conversion.BlankToNullConverter;

new example:

import org.javalite.conversion.BlankToNullConverter;

Validator interface changed a method signature

Before:

public interface Validator {
    void validate(Model model);
}

After:

public interface Validator {
    void validate(Validatable validatable);
}

This means that if you are using custom validators:

public class MyCustomValidator extends ValidatorAdapter {
    public void validate(Model m) {
    //...
    }    
}

you have to cast if the validator expects a Model:

public class MyCustomValidator extends ValidatorAdapter {
    public void validate(Validatable validatable) {
        Model m = (Model) validatable;
    //...
    }
}

Notable new features

1044 - Async: Add support for scheduled delivery time.

Allows to send commands using Async not necessarily immediately, but with a delay in milliseconds after sending.

In short, this is a new method that was added to the Async class:

async.send(QUEUE_NAME, new HelloCommand("Hello " + i), requiredTime);

The requiredTime is some time in the future, and the message will be delivered at that time. As usual, this is really a feature of Artemis, and Async is simply exposes it through its API.

1043 Implement support for Cassandra in DB-Migrator plugin

For more information, see Cassandra in DB-Migrator plugin page for more info.

1027 Implement ability to write DB migration in a Groovy Script

Sometimes you need to "massage" data during a migration, but there is no way to do this using a built-in language. As of this version, you can simply write migrations in Groovy. The database connection will be already open for your Groovy script, and ActiveJDBC will be on the script's classpath. This allows to write simple, concise migration scripts in Groovy with whatever logic that is necessary.

```groovy import org.javalite.activejdbc.Base

def books = Base.findAll("select * from books") books.each { println "The book is: ${it.title}" } /// ... more code ```

The migration file needs to have a .groovy extension to be processed as a Groovy script.

JSpec expectation method

There is a new method JSpec.expect().

It is used to verify that an exception ahs been thrown and that the message from that exception matches the expectation:

expect(AppException.class, "exact exception message here", () -> { /*code here*/ });

It provides a convenient "one liner" for expectations that is easy to read.

#1021 HTTP Request Conversion and Validation Specification

This is the largest change in this release yet. The ultimate goal for this new feature was to allow matching of Java objects and incoming HTTP requests, while providing a sensible way for data conversion and validation.

Validations

ActiveJDBC already had a considerable validation framework, but it was embedded in ActiveJDBC. With this release, you can enjoy the same validation techniques in non-model classes, follow to the Validations page for more information. This was a massive refactoring effort with the goals of a full backwards compatibility.

Dynamic paramers

ActiveWeb controllers could always pull request parameters using different versions of param methods: param("name"), params1st("name"), etc.

This feature has been available for close to 10 years: Dynamic parameters.

Implicit conversion

However, with this release, you can use real Java classes as request parameters.

For instance, say you have a class:

public class Person {
    private String  firstName, lastName;
    private int yearOfBirth = -1;
    private boolean married = false;
    public String toString(){ return "First name: " + firstName + ", last name: " + lastName + ", married: " + married; }
}

and the form looks like this:

<@form controller="people" action="add" method="POST"> 
  <input type="text" name="first_name"/>
  <input type="text" name="last_name"/>
  <input type="text" name="married"/>
  <input type="submit"/>
</@form>

The controller might process this form as anm instance of a Person class already filled with data:

public class PeopleController extends AppController {
    @POST
    public void add(Person person){
        logInfo(person);
    }
}

As you can see, the framework will:

  1. Match form parameters with class attributes using name as well as type matching. first_name -> firstName.
  2. Create a new instance of the class Person and automatically will fill it to the best of its abilities.

This allows developers to write cleaner code for HTTP request processing.

Besides HTTP froms, this mode also supports direct application/json documents posted to controllers.

For more information, follow to the Implicit conversion page.

Conversion with Validation

Since the Validations framework is general purpose, it was possible to integrate it to into ActiveWeb in order to add data validation to the Implicit conversion capability.

Lets say you have a value class:

public class Plant extends ValidationSupport {
    private String name, group, temperature;
    public Plant(){
        validatePresenceOf("name", "group");
        validateNumericalityOf("temperature").greaterThan(0).lessThan(100);
    }
} 

As you can see, you can specify validations similarly to Model validations, but they are declared in constructor.

The controller might look like this:

public class PlantController extends AppController{
public void plant(Plant plant){

    if(plant.errors.isEmpty()){
        // - happy path
    }else{
        respond(plant.errors().toJSON()).statusCode(400);
    }
}

.. so the plant.errors() will have all the validation errors if any.

At this point, you have the power of implicit conversion together with validation and direct JSON support.

For more information, see Web requests with validation


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