odata4j - Tomcat.wiki

Example: Simple In-Memory Producer

Add odata4j Library

Add the odata4j-<version>-nojpabundle.jar file to WEB-INF/lib. When using CXF, odata4j-<version>-cxfbundle.jar has to be used.

Create Producer Factory

This sample factory creates an in-memory producer that exposes thread information of the running JVM. Put the compiled class into WEB-INF/classes. ``` package org.odata4j.tomcat;

import java.util.Properties;

import org.core4j.Enumerable; import org.core4j.Func; import org.core4j.Funcs; import org.odata4j.producer.ODataProducer; import org.odata4j.producer.ODataProducerFactory; import org.odata4j.producer.inmemory.InMemoryProducer;

public class ExampleProducerFactory implements ODataProducerFactory {

@Override public ODataProducer create(Properties properties) { InMemoryProducer producer = new InMemoryProducer("example");

// expose this jvm's thread information (Thread instances) as an entity-set called "Threads"
producer.register(Thread.class, Long.class, "Threads", new Func<Iterable<Thread>>() {
  public Iterable<Thread> apply() {
    ThreadGroup tg = Thread.currentThread().getThreadGroup();
    while (tg.getParent() != null)
      tg = tg.getParent();
    Thread[] threads = new Thread[1000];
    int count = tg.enumerate(threads, true);
    return Enumerable.create(threads).take(count);
  }
}, Funcs.method(Thread.class, Long.class, "getId"));

return producer;

} } ```

Edit Deployment Descriptor

Edit the WEB-INF/web.xml file.

Using Jersey

``` http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">

OData com.sun.jersey.spi.container.servlet.ServletContainer javax.ws.rs.Application org.odata4j.jersey.producer.resources.ODataApplication 1 OData /example.svc/*

CrossDomain com.sun.jersey.spi.container.servlet.ServletContainer javax.ws.rs.Application org.odata4j.producer.resources.RootApplication 1 CrossDomain /*

``` * Instead of specifying parameter javax.ws.rs.Application it is still possible to use com.sun.jersey.config.property.resourceConfigClass. * When not using Jersey-specifc configuration (see below), the generic org.odata4j.producer.resources.DefaultODataApplication can be set.

Using CXF

``` http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">

OData org.apache.cxf.jaxrs.servlet.CXFNonSpringJaxrsServlet javax.ws.rs.Application org.odata4j.producer.resources.DefaultODataApplication 1 OData /example.svc/*

```

Specify Producer Factory

There are two possibilities to specify the OData producer factory. It can be either set using a system property or added as an additional initialization parameter to the deployment descriptor.

The system property has to be set before starting Tomcat (e.g. using the CATALINA_OPTS environment variable):

-Dodata4j.producerfactory=org.odata4j.tomcat.ExampleProducerFactory The initialization parameter requires the Jersey-specifc application org.odata4j.jersey.producer.resources.ODataApplication and is added to the corresponding <servlet> tag: <init-param> <param-name>odata4j.producerfactory</param-name> <param-value>org.odata4j.tomcat.ExampleProducerFactory</param-value> </init-param>

Run the Example

Start Tomcat and point your client (browser) to the following URL:

http://<tomcat-server>:<port>/<context-name>/example.svc/

Code