extensions/trunk/org.eclipse.persistence.example.jpa.fetchplan/src/example/FetchPlanExamples.java - eclipselink/incubator - Git at Google

 /*******************************************************************************
  * Copyright (c) 1998, 2009 Oracle. All rights reserved.
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
  * which accompanies this distribution.
  * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
  * and the Eclipse Distribution License is available at
  * http://www.eclipse.org/org/documents/edl-v10.php.
  *
  * Contributors:
  *     dclarke - Bug 288307: Extensions Incubator - FetchPlan
  ******************************************************************************/
 package example;

 import java.util.List;

 import javax.persistence.EntityManager;
 import javax.persistence.Query;

 import model.Employee;
 import model.Gender;

 import org.eclipse.persistence.config.QueryHints;
 import org.eclipse.persistence.extension.fetchplan.FetchPlan;
 import org.eclipse.persistence.extension.fetchplan.JpaFetchPlanHelper;
 import org.eclipse.persistence.jpa.JpaHelper;

 @SuppressWarnings("unchecked")
 public class FetchPlanExamples {

     /**
      * Query for all employees with a salary greater then zero using a
      * FetchGroup to only load id, firstName, lastName, gender, salary, and
      * version and then fetch their address and phone numbers using the same
      * FetchPlan.
      */
     public List<Employee> employeesFetchAddressAndPhones(EntityManager em) {
         FetchPlan fetchPlan = new FetchPlan(Employee.class);
         fetchPlan.addAttribute("firstName");
         fetchPlan.addAttribute("lastName");
         fetchPlan.addAttribute("gender");
         fetchPlan.addAttribute("salary");
         fetchPlan.addAttribute("address");
         fetchPlan.addAttribute("phoneNumbers");

         Query query = em.createQuery("SELECT e FROM Employee e WHERE e.salary > 0");

         // Configure a dynamic FetchGroup based on the FetchPlan
         query.setHint(QueryHints.FETCH_GROUP, fetchPlan.createFetchGroup());

         List<Employee> emps = query.getResultList();

         JpaFetchPlanHelper.fetch(em, fetchPlan, emps);

         return emps;
     }

     /**
      * Similar to {@link #employeesFetchAddressAndPhones(EntityManager)} but the
      * loading of the related address and phoneNumbers is optimized using batch
      * reading.
      */
     // Note: FetchGroup with FETCH (JOIN) does not work - see bug XXX
     public List<Employee> employeesFetchAddressAndPhones_optimized(EntityManager em) {
         FetchPlan fetchPlan = new FetchPlan(Employee.class);
         fetchPlan.addAttribute("firstName");
         fetchPlan.addAttribute("lastName");
         fetchPlan.addAttribute("gender");
         fetchPlan.addAttribute("salary");
         fetchPlan.addAttribute("address");
         fetchPlan.addAttribute("phoneNumbers");

         Query query = em.createQuery("SELECT e FROM Employee e WHERE e.salary > 0");

         // Configure a dynamic FetchGroup based on the FetchPlan
         query.setHint(QueryHints.FETCH_GROUP, fetchPlan.createFetchGroup());

         query.setHint(QueryHints.BATCH, "e.address");
         query.setHint(QueryHints.BATCH, "e.phoneNumbers");

         List<Employee> emps = query.getResultList();
         JpaFetchPlanHelper.fetch(em, fetchPlan, emps);

         return emps;
     }

     public List<Employee> employeesFetchAddressAndPhonesBatchAndUsingRedirector(EntityManager em) {
         FetchPlan fetchPlan = new FetchPlan(Employee.class);
         fetchPlan.addAttribute("firstName");
         fetchPlan.addAttribute("lastName");
         fetchPlan.addAttribute("gender");
         fetchPlan.addAttribute("salary");
         fetchPlan.addAttribute("address");
         fetchPlan.addAttribute("phoneNumbers");

         Query query = em.createQuery("SELECT e FROM Employee e WHERE e.salary > 0");

         // Configure a dynamic FetchGroup based on the FetchPlan
         query.setHint(QueryHints.FETCH_GROUP, fetchPlan.createFetchGroup());

         query.setHint(QueryHints.BATCH, "e.address");
         query.setHint(QueryHints.BATCH, "e.phoneNumbers");

         // Configure redirector so the FetchPlan.fetch is executed automatically
         fetchPlan.fetchOnExecute(JpaHelper.getReadAllQuery(query));

         return query.getResultList();
     }

     /**
      * Simple example retrieving just the firstName and lastName of the
      * Employee. This will also include the required identifier and optimistic
      * locking values (id and version).
      */
     public List<Employee> maleEmployeeCopyNames(EntityManager em) {
         FetchPlan fetchPlan = new FetchPlan(Employee.class);
         fetchPlan.addAttribute("firstName");
         fetchPlan.addAttribute("lastName");

         Query query = em.createQuery("SELECT e FROM Employee e WHERE e.gender = :GENDER");
         query.setParameter("GENDER", Gender.Male);

         // Configure a dynamic FetchGroup based on the FetchPlan
         query.setHint(QueryHints.FETCH_GROUP, fetchPlan.createFetchGroup());

         List<Employee> emps = query.getResultList();

         // This ensures all required relationships are loaded
         // In this case it does nothing
         JpaFetchPlanHelper.fetch(em, fetchPlan, emps);

         // Get a set of copies with only the names and required attributes
         // populated
         List<Employee> copies = JpaFetchPlanHelper.copy(em, fetchPlan, emps);

         return copies;
     }

     /**
      * This example illustrates how a FetchPlan can be constructed based on the
      * default fetch configuration of the mappings and used to copy the
      * resulting entities. This can be used to create a detached entity graph
      * where all EAGER attributes are loaded and all LAZY attributes are
      * returned as NULL.
      */
     public List<Employee> copyEagerAttributesOnly(EntityManager em) {
         Query query = em.createQuery("SELECT e FROM Employee e WHERE e.firstName IS NOT NULL AND e.lastName IS NOT NULL AND e.salary > 0 ");

         // The result of this query is a collection of Employee instances where
         // all EAGER attributes are populated and all LAZY attributes are
         // available
         // for loading with proxy objects (FetchGroup for basics, ValueHolders
         // for 1:1 and M:1, and IndirectList/Map/Set for collections). If
         // serialized at this point these will not appear as null.
         List<Employee> emps = query.getResultList();

         // Create a FetchPlan based on the default FetchGroup
         FetchPlan fetchPlan = new FetchPlan(Employee.class);
         JpaFetchPlanHelper.addDefaultFetchAttributes(em, fetchPlan);

         // Get a set of copies with only the names and required attributes
         // populated
         List<Employee> copies = JpaFetchPlanHelper.copy(em, fetchPlan, emps);

         return copies;
     }

     /**
      * Load all employees's first and last names (plus required id and version)
      * attributes based on a FetchGroup and copy the results based on this plan.
      */
     public List<Employee> employeeCopyNamesWithFetchGroup(EntityManager em) {
         Query query = em.createQuery("SELECT e FROM Employee e WHERE e.gender IS NOT NULL");

         FetchPlan fetchPlan = new FetchPlan(Employee.class);
         fetchPlan.addAttribute("firstName");
         fetchPlan.addAttribute("lastName");

         // Configure a dynamic FetchGroup based on the FetchPlan
         query.setHint(QueryHints.FETCH_GROUP, fetchPlan.createFetchGroup());

         List<Employee> emps = query.getResultList();

         return JpaFetchPlanHelper.copy(em, fetchPlan, emps);
     }

     /**
      * Create copies of managed objects requiring relationships that were not
      * loaded in the initial query. The copy operation will force the fetching
      * of required relationships.
      */
     public List<Employee> employeeCopyWithNamesAddressAndPhones(EntityManager em) {
         Query query = em.createQuery("SELECT e FROM Employee e WHERE e.salary > 0");

         FetchPlan fetchPlan = new FetchPlan(Employee.class);
         fetchPlan.addAttribute("firstName");
         fetchPlan.addAttribute("lastName");
         fetchPlan.addAttribute("address");
         fetchPlan.addAttribute("phoneNumbers");

         List<Employee> emps = query.getResultList();

         return JpaFetchPlanHelper.copy(em, fetchPlan, emps);
     }

     /**
      * Create copies of managed objects requiring relationships that were not
      * loaded in the initial query. The copy operation will force the fetching
      * of required relationships.
      */
     public List<Employee> employeeCopyWithNamesAddressAndPhonesWithBatching(EntityManager em) {
         Query query = em.createQuery("SELECT e FROM Employee e WHERE e.salary > 0");

         FetchPlan fetchPlan = new FetchPlan(Employee.class);
         fetchPlan.addAttribute("firstName");
         fetchPlan.addAttribute("lastName");
         fetchPlan.addAttribute("address");
         fetchPlan.addAttribute("phoneNumbers");

         // Optimize graph loading using batching
         query.setHint(QueryHints.BATCH, "e.address");
         query.setHint(QueryHints.BATCH, "e.phoneNumbers");

         List<Employee> emps = query.getResultList();

         return JpaFetchPlanHelper.copy(em, fetchPlan, emps);
     }

     /**
      * Illustrate a multi-level fetch
      */
     public List<Employee> managerManagerManagerFetchWithNames(EntityManager em) {
         FetchPlan fetchPlan = new FetchPlan(Employee.class);
         fetchPlan.addAttribute("firstName");
         fetchPlan.addAttribute("lastName");
         fetchPlan.addAttribute("manager.firstName");
         fetchPlan.addAttribute("manager.lastName");
         fetchPlan.addAttribute("manager.manager.firstName");
         fetchPlan.addAttribute("manager.manager.lastName");

         Query query = em.createQuery("SELECT e FROM Employee e WHERE e.manager.manager IS NOT NULL");

         List<Employee> emps = query.getResultList();

         JpaFetchPlanHelper.fetch(em, fetchPlan, emps);

         return emps;
     }

     /**
      * Example of a composite select returning both an Employee and its count of
      * PhoneNumbers. To use the {@link FetchPlan} in this case you must also
      * provide the index into the resulting Object[].
      */
     public List<Object[]> employeeAddress_ReturnBoth(EntityManager em) {
         FetchPlan fetchPlan = new FetchPlan(Employee.class);
         fetchPlan.addAttribute("address");
         fetchPlan.addAttribute("phoneNumbers");

         Query query = em.createQuery("SELECT e, e.address FROM Employee e WHERE e.firstName <> e.lastName");
         List<Object[]> results = query.getResultList();

         JpaFetchPlanHelper.fetch(em, fetchPlan, results, 0);

         return results;
     }

     /**
      * Example of using a FetchPlan to retrieve an entity and copy a partial
      * unmanaged graph of the entity which is then modified and merged back into
      * the persistence context.
      *
      * Note: caller manages transactions
      */
     public void copyMergeExample(EntityManager em, boolean clear) {
         FetchPlan fetchPlan = new FetchPlan(Employee.class);
         fetchPlan.addAttribute("firstName");
         fetchPlan.addAttribute("lastName");
         fetchPlan.addAttribute("address");
         fetchPlan.addAttribute("phoneNumbers");

         int minId = ((Number) em.createQuery("SELECT MIN(e.id) FROM Employee e").getSingleResult()).intValue();

         Query query = em.createQuery("SELECT e FROM Employee e WHERE e.id = " + minId);
         query.setHint(QueryHints.FETCH_GROUP, fetchPlan.createFetchGroup());

         Employee emp = (Employee) query.getSingleResult();

         Employee copy = JpaFetchPlanHelper.copy(em, fetchPlan, emp);

         copy.setSalary(Integer.MAX_VALUE);
         copy.setFirstName(emp.getLastName());
         copy.setLastName(emp.getFirstName());

         JpaFetchPlanHelper.merge(em, fetchPlan, copy);
     }

     /**
      *
      */
     public List<Employee> createFetchPlanFromDefaultFetchGroup(EntityManager em) {
         FetchPlan fetchPlan = new FetchPlan(Employee.class);
         JpaFetchPlanHelper.addDefaultFetchAttributes(em, fetchPlan);

         Query query = em.createQuery("SELECT e FROM Employee e WHERE e.salary > 0");
         query.setHint(QueryHints.FETCH_GROUP, fetchPlan.createFetchGroup());

         List<Employee> emps = query.getResultList();

         JpaFetchPlanHelper.fetch(em, fetchPlan, emps);

         return emps;
     }

 }
	/*******************************************************************************
	* Copyright (c) 1998, 2009 Oracle. All rights reserved.
	* This program and the accompanying materials are made available under the
	* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
	* which accompanies this distribution.
	* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
	* and the Eclipse Distribution License is available at
	* http://www.eclipse.org/org/documents/edl-v10.php.
	*
	* Contributors:
	* dclarke - Bug 288307: Extensions Incubator - FetchPlan
	******************************************************************************/
	package example;

	import java.util.List;

	import javax.persistence.EntityManager;
	import javax.persistence.Query;

	import model.Employee;
	import model.Gender;

	import org.eclipse.persistence.config.QueryHints;
	import org.eclipse.persistence.extension.fetchplan.FetchPlan;
	import org.eclipse.persistence.extension.fetchplan.JpaFetchPlanHelper;
	import org.eclipse.persistence.jpa.JpaHelper;

	@SuppressWarnings("unchecked")
	public class FetchPlanExamples {

	/**
	* Query for all employees with a salary greater then zero using a
	* FetchGroup to only load id, firstName, lastName, gender, salary, and
	* version and then fetch their address and phone numbers using the same
	* FetchPlan.
	*/
	public List<Employee> employeesFetchAddressAndPhones(EntityManager em) {
	FetchPlan fetchPlan = new FetchPlan(Employee.class);
	fetchPlan.addAttribute("firstName");
	fetchPlan.addAttribute("lastName");
	fetchPlan.addAttribute("gender");
	fetchPlan.addAttribute("salary");
	fetchPlan.addAttribute("address");
	fetchPlan.addAttribute("phoneNumbers");

	Query query = em.createQuery("SELECT e FROM Employee e WHERE e.salary > 0");

	// Configure a dynamic FetchGroup based on the FetchPlan
	query.setHint(QueryHints.FETCH_GROUP, fetchPlan.createFetchGroup());

	List<Employee> emps = query.getResultList();

	JpaFetchPlanHelper.fetch(em, fetchPlan, emps);

	return emps;
	}

	/**
	* Similar to {@link #employeesFetchAddressAndPhones(EntityManager)} but the
	* loading of the related address and phoneNumbers is optimized using batch
	* reading.
	*/
	// Note: FetchGroup with FETCH (JOIN) does not work - see bug XXX
	public List<Employee> employeesFetchAddressAndPhones_optimized(EntityManager em) {
	FetchPlan fetchPlan = new FetchPlan(Employee.class);
	fetchPlan.addAttribute("firstName");
	fetchPlan.addAttribute("lastName");
	fetchPlan.addAttribute("gender");
	fetchPlan.addAttribute("salary");
	fetchPlan.addAttribute("address");
	fetchPlan.addAttribute("phoneNumbers");

	Query query = em.createQuery("SELECT e FROM Employee e WHERE e.salary > 0");

	// Configure a dynamic FetchGroup based on the FetchPlan
	query.setHint(QueryHints.FETCH_GROUP, fetchPlan.createFetchGroup());

	query.setHint(QueryHints.BATCH, "e.address");
	query.setHint(QueryHints.BATCH, "e.phoneNumbers");

	List<Employee> emps = query.getResultList();
	JpaFetchPlanHelper.fetch(em, fetchPlan, emps);

	return emps;
	}

	public List<Employee> employeesFetchAddressAndPhonesBatchAndUsingRedirector(EntityManager em) {
	FetchPlan fetchPlan = new FetchPlan(Employee.class);
	fetchPlan.addAttribute("firstName");
	fetchPlan.addAttribute("lastName");
	fetchPlan.addAttribute("gender");
	fetchPlan.addAttribute("salary");
	fetchPlan.addAttribute("address");
	fetchPlan.addAttribute("phoneNumbers");

	Query query = em.createQuery("SELECT e FROM Employee e WHERE e.salary > 0");

	// Configure a dynamic FetchGroup based on the FetchPlan
	query.setHint(QueryHints.FETCH_GROUP, fetchPlan.createFetchGroup());

	query.setHint(QueryHints.BATCH, "e.address");
	query.setHint(QueryHints.BATCH, "e.phoneNumbers");

	// Configure redirector so the FetchPlan.fetch is executed automatically
	fetchPlan.fetchOnExecute(JpaHelper.getReadAllQuery(query));

	return query.getResultList();
	}

	/**
	* Simple example retrieving just the firstName and lastName of the
	* Employee. This will also include the required identifier and optimistic
	* locking values (id and version).
	*/
	public List<Employee> maleEmployeeCopyNames(EntityManager em) {
	FetchPlan fetchPlan = new FetchPlan(Employee.class);
	fetchPlan.addAttribute("firstName");
	fetchPlan.addAttribute("lastName");

	Query query = em.createQuery("SELECT e FROM Employee e WHERE e.gender = :GENDER");
	query.setParameter("GENDER", Gender.Male);

	// Configure a dynamic FetchGroup based on the FetchPlan
	query.setHint(QueryHints.FETCH_GROUP, fetchPlan.createFetchGroup());

	List<Employee> emps = query.getResultList();

	// This ensures all required relationships are loaded
	// In this case it does nothing
	JpaFetchPlanHelper.fetch(em, fetchPlan, emps);

	// Get a set of copies with only the names and required attributes
	// populated
	List<Employee> copies = JpaFetchPlanHelper.copy(em, fetchPlan, emps);

	return copies;
	}

	/**
	* This example illustrates how a FetchPlan can be constructed based on the
	* default fetch configuration of the mappings and used to copy the
	* resulting entities. This can be used to create a detached entity graph
	* where all EAGER attributes are loaded and all LAZY attributes are
	* returned as NULL.
	*/
	public List<Employee> copyEagerAttributesOnly(EntityManager em) {
	Query query = em.createQuery("SELECT e FROM Employee e WHERE e.firstName IS NOT NULL AND e.lastName IS NOT NULL AND e.salary > 0 ");

	// The result of this query is a collection of Employee instances where
	// all EAGER attributes are populated and all LAZY attributes are
	// available
	// for loading with proxy objects (FetchGroup for basics, ValueHolders
	// for 1:1 and M:1, and IndirectList/Map/Set for collections). If
	// serialized at this point these will not appear as null.
	List<Employee> emps = query.getResultList();

	// Create a FetchPlan based on the default FetchGroup
	FetchPlan fetchPlan = new FetchPlan(Employee.class);
	JpaFetchPlanHelper.addDefaultFetchAttributes(em, fetchPlan);

	// Get a set of copies with only the names and required attributes
	// populated
	List<Employee> copies = JpaFetchPlanHelper.copy(em, fetchPlan, emps);

	return copies;
	}

	/**
	* Load all employees's first and last names (plus required id and version)
	* attributes based on a FetchGroup and copy the results based on this plan.
	*/
	public List<Employee> employeeCopyNamesWithFetchGroup(EntityManager em) {
	Query query = em.createQuery("SELECT e FROM Employee e WHERE e.gender IS NOT NULL");

	FetchPlan fetchPlan = new FetchPlan(Employee.class);
	fetchPlan.addAttribute("firstName");
	fetchPlan.addAttribute("lastName");

	// Configure a dynamic FetchGroup based on the FetchPlan
	query.setHint(QueryHints.FETCH_GROUP, fetchPlan.createFetchGroup());

	List<Employee> emps = query.getResultList();

	return JpaFetchPlanHelper.copy(em, fetchPlan, emps);
	}

	/**
	* Create copies of managed objects requiring relationships that were not
	* loaded in the initial query. The copy operation will force the fetching
	* of required relationships.
	*/
	public List<Employee> employeeCopyWithNamesAddressAndPhones(EntityManager em) {
	Query query = em.createQuery("SELECT e FROM Employee e WHERE e.salary > 0");

	FetchPlan fetchPlan = new FetchPlan(Employee.class);
	fetchPlan.addAttribute("firstName");
	fetchPlan.addAttribute("lastName");
	fetchPlan.addAttribute("address");
	fetchPlan.addAttribute("phoneNumbers");

	List<Employee> emps = query.getResultList();

	return JpaFetchPlanHelper.copy(em, fetchPlan, emps);
	}

	/**
	* Create copies of managed objects requiring relationships that were not
	* loaded in the initial query. The copy operation will force the fetching
	* of required relationships.
	*/
	public List<Employee> employeeCopyWithNamesAddressAndPhonesWithBatching(EntityManager em) {
	Query query = em.createQuery("SELECT e FROM Employee e WHERE e.salary > 0");

	FetchPlan fetchPlan = new FetchPlan(Employee.class);
	fetchPlan.addAttribute("firstName");
	fetchPlan.addAttribute("lastName");
	fetchPlan.addAttribute("address");
	fetchPlan.addAttribute("phoneNumbers");

	// Optimize graph loading using batching
	query.setHint(QueryHints.BATCH, "e.address");
	query.setHint(QueryHints.BATCH, "e.phoneNumbers");

	List<Employee> emps = query.getResultList();

	return JpaFetchPlanHelper.copy(em, fetchPlan, emps);
	}

	/**
	* Illustrate a multi-level fetch
	*/
	public List<Employee> managerManagerManagerFetchWithNames(EntityManager em) {
	FetchPlan fetchPlan = new FetchPlan(Employee.class);
	fetchPlan.addAttribute("firstName");
	fetchPlan.addAttribute("lastName");
	fetchPlan.addAttribute("manager.firstName");
	fetchPlan.addAttribute("manager.lastName");
	fetchPlan.addAttribute("manager.manager.firstName");
	fetchPlan.addAttribute("manager.manager.lastName");

	Query query = em.createQuery("SELECT e FROM Employee e WHERE e.manager.manager IS NOT NULL");

	List<Employee> emps = query.getResultList();

	JpaFetchPlanHelper.fetch(em, fetchPlan, emps);

	return emps;
	}

	/**
	* Example of a composite select returning both an Employee and its count of
	* PhoneNumbers. To use the {@link FetchPlan} in this case you must also
	* provide the index into the resulting Object[].
	*/
	public List<Object[]> employeeAddress_ReturnBoth(EntityManager em) {
	FetchPlan fetchPlan = new FetchPlan(Employee.class);
	fetchPlan.addAttribute("address");
	fetchPlan.addAttribute("phoneNumbers");

	Query query = em.createQuery("SELECT e, e.address FROM Employee e WHERE e.firstName <> e.lastName");
	List<Object[]> results = query.getResultList();

	JpaFetchPlanHelper.fetch(em, fetchPlan, results, 0);

	return results;
	}

	/**
	* Example of using a FetchPlan to retrieve an entity and copy a partial
	* unmanaged graph of the entity which is then modified and merged back into
	* the persistence context.
	*
	* Note: caller manages transactions
	*/
	public void copyMergeExample(EntityManager em, boolean clear) {
	FetchPlan fetchPlan = new FetchPlan(Employee.class);
	fetchPlan.addAttribute("firstName");
	fetchPlan.addAttribute("lastName");
	fetchPlan.addAttribute("address");
	fetchPlan.addAttribute("phoneNumbers");

	int minId = ((Number) em.createQuery("SELECT MIN(e.id) FROM Employee e").getSingleResult()).intValue();

	Query query = em.createQuery("SELECT e FROM Employee e WHERE e.id = " + minId);
	query.setHint(QueryHints.FETCH_GROUP, fetchPlan.createFetchGroup());

	Employee emp = (Employee) query.getSingleResult();

	Employee copy = JpaFetchPlanHelper.copy(em, fetchPlan, emp);

	copy.setSalary(Integer.MAX_VALUE);
	copy.setFirstName(emp.getLastName());
	copy.setLastName(emp.getFirstName());

	JpaFetchPlanHelper.merge(em, fetchPlan, copy);
	}

	/**
	*
	*/
	public List<Employee> createFetchPlanFromDefaultFetchGroup(EntityManager em) {
	FetchPlan fetchPlan = new FetchPlan(Employee.class);
	JpaFetchPlanHelper.addDefaultFetchAttributes(em, fetchPlan);

	Query query = em.createQuery("SELECT e FROM Employee e WHERE e.salary > 0");
	query.setHint(QueryHints.FETCH_GROUP, fetchPlan.createFetchGroup());

	List<Employee> emps = query.getResultList();

	JpaFetchPlanHelper.fetch(em, fetchPlan, emps);

	return emps;
	}

	}