Pico + Nano + Groovy

Groovyも1.0になったし、動的なクラス生成を使ってインターフェースレスにDIコンテナを使うのが、ナウなヤングにトレンディかも…と考えて、少し触ってみる。

依存するライブラリは次の通り。

• asm-2.2.jar
• antlr-2.7.5.jar
• groovy-1.0.jar
• nanocontainer-1.0.jar
• picocontainer-1.2.jar

コンポーネント

public class Foo {
    private Bar bar;
    private Zoo zoo;

    public Foo(Bar bar, Zoo zoo) { this.bar = bar; this.zoo = zoo; }
    public void func() { System.out.println("Foo#func()"); bar.func(); zoo.func(); }
}

public class Bar {
    private Baz baz;

    public Bar(Baz baz) { this.baz = baz; }
    public void func() { System.out.println("Bar#func()"); baz.func(); }
}

public class Zoo {
    public void func() { System.out.println("Zoo#func()"); }
}

public class Baz {
    public void func() { System.out.println("Baz#func()"); }
}

エントリクラス

public class Main {

    public static void main(String[] args) {
        try { Main main = new Main(); main.__main__(args); } catch (Exception e) { e.printStackTrace(); }
    }

    private void __main__(String[] args) throws Exception {
        PicoContainer pico = buildContainer();
        Foo foo = (Foo) pico.getComponentInstanceOfType(Foo.class);
        foo.func();
    }

    private PicoContainer buildContainer() throws FileNotFoundException {
        Reader script = new FileReader("nanocontainer.groovy");
        GroovyContainerBuilder builder = new GroovyContainerBuilder(script, getClass().getClassLoader());

        ObjectReference containerRef = new SimpleReference();
        builder.buildContainer(containerRef, new SimpleReference(), null, true);

        return (PicoContainer) containerRef.get();
    }

}

Groovyスクリプト

import pico_nano.*

pico = builder.container(parent:parent) {
	component(class:Foo)
	component(class:Bar)
	component(class:Zoo)
	component(class:Baz)
}

実行結果

Foo#func()
Bar#func()
Baz#func()
Zoo#func()