Overview

As noted in the Injection of env-entry Example , the EJB 3.0 supported env-entry types are fairly limited. Also the use of several tags in an ejb-jar.xml can get a bit verbose.

OpenEJB does not restrict you to just these data types or require you to use an ejb-jar.xml to declare them.

@Resource can be used on any type for which there is java.beans.PropertyEditor
You may install your own PropertyEditors and package them with your app.
Java Generics are supported (e.g. List myURIs)
You may use a META-INF/env-entries.properties file as an alternative to an ejb-jar.xml

See Built-in Type Converters for a full list of supported env-entry types.

The source for this example is the "custom-injection" directory located in the openejb-examples.zip available on the download page.

The Code

Bean Class

@Stateless
public class Stratocaster {

    @Resource(name = "pickups")
    private List<Pickup> pickups;

    @Resource(name = "style")
    private Style style;

    @Resource(name = "dateCreated")
    private Date dateCreated;

    @Resource(name = "guitarStringGuages")
    private Map<String, Float> guitarStringGuages;

    @Resource(name = "certificateOfAuthenticity")
    private File certificateOfAuthenticity;

    public Date getDateCreated() {
        return dateCreated;
    }

    /**
     * Gets the guage of the electric guitar strings
     * used in this guitar.
     *
     * @param string
     * @return
     */
    public float getStringGuage(String string) {
        return guitarStringGuages.get(string);
    }

    public List<Pickup> getPickups() {
        return pickups;
    }

    public Style getStyle() {
        return style;
    }

    public File getCertificateOfAuthenticity() {
        return certificateOfAuthenticity;
    }
}

The META-INF/env-entries.properties file

guitarStringGuages=E1=0.052\nA=0.042\nD=0.030\nG=0.017\nB=0.013\nE=0.010
certificateOfAuthenticity=/tmp/strat-certificate.txt
dateCreated=1962-03-01
pickups=S,S,S
style=VINTAGE

The Custom Type and Editor

Support for java.lang.Enum types is already built-in, but we’ve decided we’d like to allow abbreviated versions of the enum constants to be usable. We do this by creating a custom PropertyEditor for our Pickup enum like so:

public class PickupEditor extends java.beans.PropertyEditorSupport {
    public void setAsText(String text) throws IllegalArgumentException {
        text = text.trim();

        if (text.equalsIgnoreCase("H")) setValue(Pickup.HUMBUCKER);
        else if (text.equalsIgnoreCase("S")) setValue(Pickup.SINGLE_COIL);
        else throw new IllegalStateException("H and S are the only supported Pickup aliases");
    }
}

We cleverly install this PropertyEditor in a static block in the Pickup class that will be executed should someone actually reference the Pickup type.

public enum Pickup {

    HUMBUCKER,
    SINGLE_COIL;

    // Here's the little magic where we register the PickupEditor
    // which knows how to create this object from a string.
    // You can add any of your own Property Editors in the same way.
    static {
        PropertyEditorManager.registerEditor(Pickup.class, PickupEditor.class);
    }
}

Test Case

public class StratocasterTest extends TestCase {

    @EJB
    private Stratocaster strat;

    public void test() throws Exception {
        EJBContainer.createEJBContainer().getContext().bind("inject", this);

        Date date = DateFormat.getDateInstance(DateFormat.MEDIUM, Locale.US).parse("Mar 1, 1962");
        assertEquals("Strat.getDateCreated()", date, strat.getDateCreated());

        List<Pickup> pickups = asList(Pickup.SINGLE_COIL, Pickup.SINGLE_COIL, Pickup.SINGLE_COIL);
        assertEquals("Strat.getPickups()", pickups, strat.getPickups());

        assertEquals("Strat.getStyle()", Style.VINTAGE, strat.getStyle());

        assertEquals("Strat.getStringGuage(\"E1\")", 0.052F, strat.getStringGuage("E1"));
        assertEquals("Strat.getStringGuage(\"A\")", 0.042F, strat.getStringGuage("A"));
        assertEquals("Strat.getStringGuage(\"D\")", 0.030F, strat.getStringGuage("D"));
        assertEquals("Strat.getStringGuage(\"G\")", 0.017F, strat.getStringGuage("G"));
        assertEquals("Strat.getStringGuage(\"B\")", 0.013F, strat.getStringGuage("B"));
        assertEquals("Strat.getStringGuage(\"E\")", 0.010F, strat.getStringGuage("E"));

        File file = new File("/tmp/strat-certificate.txt");
        assertEquals("Strat.getCertificateOfAuthenticity()", file,strat.getCertificateOfAuthenticity());


    }
}

Running it

Running the example is fairly simple. In the "custom-injection" directory of the openejb:download.html[examples zip], just run:

$ mvn clean install

Which should create output like the following.

-------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running org.superbiz.enventries.StratocasterTest
Apache OpenEJB 3.1-SNAPSHOT    build: 20080409-12:05
http://tomee.apache.org/
INFO - openejb.home = /Users/dblevins/work/openejb3/examples/custom-injection
INFO - openejb.base = /Users/dblevins/work/openejb3/examples/custom-injection
INFO - Configuring Service(id=Default Security Service, type=SecurityService, provider-id=Default Security Service)
INFO - Configuring Service(id=Default Transaction Manager, type=TransactionManager, provider-id=Default Transaction Manager)
INFO - Configuring Service(id=Default JDK 1.3 ProxyFactory, type=ProxyFactory, provider-id=Default JDK 1.3 ProxyFactory)
INFO - Found EjbModule in classpath: /Users/dblevins/work/openejb3/examples/custom-injection/target/classes
INFO - Configuring app: /Users/dblevins/work/openejb3/examples/custom-injection/target/classes
INFO - Configuring Service(id=Default Stateless Container, type=Container, provider-id=Default Stateless Container)
INFO - Auto-creating a container for bean StratocasterImpl: Container(type=STATELESS, id=Default Stateless Container)
INFO - Loaded Module: /Users/dblevins/work/openejb3/examples/custom-injection/target/classes
INFO - Assembling app: /Users/dblevins/work/openejb3/examples/custom-injection/target/classes
INFO - Jndi(name=StratocasterImplLocal) --> Ejb(deployment-id=StratocasterImpl)
INFO - Created Ejb(deployment-id=StratocasterImpl, ejb-name=StratocasterImpl, container=Default Stateless Container)
INFO - Deployed Application(path=/Users/dblevins/work/openejb3/examples/custom-injection/target/classes)
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.705 sec

Results :

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0