ex7_23.txt

j2ee core design patterns

Example 7.23 ResourceEntityBean.java: Composite Entity 

package corepatterns.apps.psa.ejb;

import corepatterns.apps.psa.core.*;
import corepatterns.apps.psa.dao.*;
import java.sql.*;

import javax.sql.*;
import java.util.*;
import javax.ejb.*;
import javax.naming.*;

public class ResourceEntityBean implements EntityBean {
	public String employeeId;
	public String lastName;
	public String firstName;
	public String departmentId;
   ...
	
	// Collection of BlockOutTime Dependent objects
	public Collection blockoutTimes;

	// Collection of SkillSet Dependent objects
	public Collection skillSets;

	...

	private EntityContext context;

	// Entity Bean methods implementation
	public String ejbCreate(ResourceTO resource) 
	throws CreateException {
		try {
			this.employeeId = resource.employeeId;
			setResourceData(resource);
			getResourceDAO().create(resource);
		} catch (Exception ex) {
			throw new EJBException("Reason:" + ...);
		}
		return this.employeeId;
	}
	
	public String ejbFindByPrimaryKey(String primaryKey) 
	throws FinderException {
		boolean result;
		try {
			ResourceDAO resourceDAO = getResourceDAO();
			result =  resourceDAO.findResource(primaryKey);
		} catch (Exception ex) {
			throw new EJBException("Reason:" + ...);
		}
		if (result) {
			return primaryKey;
		}
		else {
			throw new ObjectNotFoundException(...);
		}
	}
	
	public void ejbRemove() {
		try {
			// Remove dependent objects
			if (this.skillSets != null) {
				SkillSetDAO skillSetDAO = getSkillSetDAO();
				skillSetDAO.deleteAll(employeeId);
				skillSets = null;
			}
			if (this.blockoutTime != null) {
				BlockOutTimeDAO blockouttimeDAO =
					getBlockOutTimeDAO();
				blockouttimeDAO.deleteAll(employeeId);
				blockOutTimes = null;
			}

			// Remove the resource from the persistent store
			ResourceDAO resourceDAO = new ResourceDAO();
			resourceDAO.delete(employeeId);
		} catch (ResourceException ex) {
			throw new EJBException("Reason:"+...);
		} catch (BlockOutTimeException ex) {
			throw new EJBException("Reason:"+...);
		} catch (Exception exception) {
			...
		}
	}
	

	public void setEntityContext(EntityContext context) {
		this.context = context;
	}
	
	public void unsetEntityContext() {
		context = null;
	}
	
	public void ejbActivate() {
		employeeId = (String)context.getPrimaryKey();
	}
	
	public void ejbPassivate() {
		employeeId = null;
	}
	
	public void ejbLoad() {
		try {
			// load the resource info from
			ResourceDAO resourceDAO = getResourceDAO();
			setResourceData((ResourceTO) 
				resourceDAO.findResource(employeeId));
			
			// Load other dependent objects, if necessary
			...
		} catch (Exception ex) {
			throw new EJBException("Reason:" + ...);
		}
	}
	
	public void ejbStore() {
		try {
			// Store resource information
			getResourceDAO().update(getResourceData());

			// Store dependent objects as needed
			...
		} catch (SkillSetException ex) {
			throw new EJBException("Reason:" + ...);
		} catch (BlockOutTimeException ex) {
			throw new EJBException("Reason:" + ...);
		}
		...
	}

	public void ejbPostCreate(ResourceTO resource) {
	}

	// Method to Get Resource transfer object
	public ResourceTO getResourceTO() {
		// create a new Resource transfer object
		ResourceTO resourceTO = new ResourceTO(employeeId);

		// copy all values 
		resourceTO.lastName = lastName;
		resourceTO.firstName = firstName;
		resourceTO.departmentId = departmentId;
		...
		return resourceTO;
	}

	public void setResourceData(ResourceTO resourceTO) {
		// copy values from transfer object into entity bean
		employeeId = resourceTO.employeeId;
		lastName = resourceTO.lastName;
		...
	}

	// Method to get dependent transfer objects
	public Collection getSkillSetsData() {
		// If skillSets is not loaded, load it first.
		// See Lazy Load strategy implementation.
		return skillSets;	
	}
	...

	// other get and set methods as needed
	...

	// Entity bean business methods
	public void addBlockOutTimes(Collection moreBOTs) 
	throws BlockOutTimeException {
		// Note: moreBOTs is a collection of BlockOutTimeTO
		// objects
		try {
			Iterator moreIter = moreBOTs.iterator();
			while (moreIter.hasNext()) {
				BlockOutTimeTO botTO =
					(BlockOutTimeTO) moreIter.next();
				if (! (blockOutTimeExists(botTO))) {
					// add BlockOutTimeTO to collection
					botTO.setNew();
					blockOutTime.add(botTO);
				} else {
					// BlockOutTimeTO already exists, cannot add
					throw new BlockOutTimeException(...);
				}
			}
		} catch (Exception exception) {
			throw new EJBException(...);
		}
	}

	public void addSkillSet(Collection moreSkills) 
	throws SkillSetException {
		// similar to addBlockOutTime() implementation
		...
	}

	...

	public void updateBlockOutTime(Collection updBOTs) 
	throws BlockOutTimeException {
		try {
			Iterator botIter = blockOutTimes.iterator();
			Iterator updIter = updBOTs.iterator();
			while (updIter.hasNext()) {
				BlockOutTimeTO botTO =
					(BlockOutTimeTO) updIter.next();
				while (botIter.hasNext()) {
					BlockOutTimeTO existingBOT = 
						(BlockOutTimeTO) botIter.next();
					// compare key values to locate BlockOutTime
					if (existingBOT.equals(botTO)) {
						// Found BlockOutTime in collection
						// replace old BlockOutTimeTO with new one
						botTO.setDirty(); //modified old dependent
						botTO.resetNew(); //not a new dependent
						existingBOT = botTO;
					}
				}
			}

		} catch (Exception exc) {
			throw new EJBException(...);
		}
	}

	public void updateSkillSet(Collection updSkills) 
	throws CommitmentException {
		// similar to updateBlockOutTime...
		...
	}

	...

}