BlueprintELResolver.java

package org.camunda.bpm.extension.osgi.blueprint;

import java.beans.FeatureDescriptor;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.logging.Logger;

import org.camunda.bpm.engine.delegate.JavaDelegate;
import org.camunda.bpm.engine.impl.javax.el.ELContext;
import org.camunda.bpm.engine.impl.javax.el.ELResolver;

/**
 * @see org.camunda.bpm.engine.test.spring.ApplicationContextElResolver
 */
public class BlueprintELResolver extends ELResolver {

	private static final Logger LOGGER = Logger
			.getLogger(BlueprintELResolver.class.getName());
	private Map<String, JavaDelegate> delegateMap = new HashMap<String, JavaDelegate>();

	@Override
  public Object getValue(ELContext context, Object base, Object property) {
		if (base == null) {
			// according to javadoc, can only be a String
			String key = (String) property;
			for (String name : delegateMap.keySet()) {
				if (name.equalsIgnoreCase(key)) {
					context.setPropertyResolved(true);
					return delegateMap.get(name);
				}
			}
		}
		return null;
	}

	public void bindService(JavaDelegate delegate, Map<?, ?> props) {
		String name = (String) props.get("osgi.service.blueprint.compname");
		delegateMap.put(name, delegate);
		LOGGER.info("added service to delegate cache " + name);
	}

	/**
   * @param delegate the delegate, necessary parameter because of Blueprint 
   */
	public void unbindService(JavaDelegate delegate, Map<?, ?> props) {
		String name = (String) props.get("osgi.service.blueprint.compname");
		if (delegateMap.containsKey(name)) {
			delegateMap.remove(name);
		}
		LOGGER.info("removed service from delegate cache " + name);
	}

	@Override
  public boolean isReadOnly(ELContext context, Object base, Object property) {
		return true;
	}

	@Override
  public void setValue(ELContext context, Object base, Object property,
			Object value) {
	}

	@Override
  public Class<?> getCommonPropertyType(ELContext context, Object arg) {
		return Object.class;
	}

	@Override
  public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext context,
			Object arg) {
		return null;
	}

	@Override
  public Class<?> getType(ELContext context, Object arg1, Object arg2) {
		return Object.class;
	}
}