openjpa-persistence/src/main/java/org/apache/openjpa/persistence/criteria/PathImpl.java - openjpa - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing,
  * software distributed under the License is distributed on an
  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  * KIND, either express or implied.  See the License for the
  * specific language governing permissions and limitations
  * under the License.
  */

 package org.apache.openjpa.persistence.criteria;

 import javax.persistence.criteria.Expression;
 import javax.persistence.criteria.Join;
 import javax.persistence.criteria.JoinType;
 import javax.persistence.criteria.Path;
 import javax.persistence.metamodel.Bindable;
 import javax.persistence.metamodel.ManagedType;
 import javax.persistence.metamodel.MapAttribute;
 import javax.persistence.metamodel.PluralAttribute;
 import javax.persistence.metamodel.SingularAttribute;
 import javax.persistence.metamodel.Type;
 import javax.persistence.metamodel.Type.PersistenceType;

 import org.apache.openjpa.kernel.exps.ExpressionFactory;
 import org.apache.openjpa.kernel.exps.Value;
 import org.apache.openjpa.meta.ClassMetaData;
 import org.apache.openjpa.meta.FieldMetaData;
 import org.apache.openjpa.persistence.meta.Members;
 import org.apache.openjpa.persistence.meta.Members.Member;

 /**
  * Path is an expression representing a persistent attribute traversed from a parent path.
  * The type of the path is the type of the persistent attribute.
  * If the persistent attribute is bindable, then further path can be traversed from this path.
  *
  * @author Pinaki Poddar
  * @author Fay Wang
  *
  * @param <Z> the type of the parent path
  * @param <X> the type of this path
  */
 class PathImpl<Z,X> extends ExpressionImpl<X> implements Path<X> {
     protected final PathImpl<?,Z> _parent;
     protected final Members.Member<? super Z,?> _member;
     private boolean isEmbedded = false;
     private PathImpl<?,?> _correlatedPath;

     /**
      * Protected constructor use by root path which neither represent a member nor has a parent.
      */
     protected PathImpl(Class<X> cls) {
         super(cls);
         _parent = null;
         _member = null;
     }

     /**
      * Create a path from the given parent representing the given member.
      *
      * @param parent the path from which this path needs to be constructed. Must not be null.
      * @param member the persistent property that represents this path.
      * @param cls denotes the type expressed by this path.
      */
     public PathImpl(PathImpl<?,Z> parent, Members.Member<? super Z, ?> member, Class<X> cls) {
         super(cls);
         _parent = parent;
         if (_parent.isEmbedded) {
             FieldMetaData fmd = getEmbeddedFieldMetaData(member.fmd);
             _member = new Members.SingularAttributeImpl(member.owner, fmd);
         } else {
             _member = member;
         }
         isEmbedded = _member.fmd.isElementCollection() ? _member.fmd.getElement().isEmbedded() :
             _member.fmd.isEmbedded();
     }

     /**
      * Gets the bindable object that corresponds to the path expression.
      *
      * @throws IllegalArgumentException if this path is not bindable
      */
     public Bindable<X> getModel() {
         if (_member instanceof Bindable<?> == false) {
             throw new IllegalArgumentException(this + " represents a basic path and not a bindable");
         }
         return (Bindable<X>)_member;
     }

     /**
      *  Gets the parent of this path or null if this path is the root.
      */
     public final Path<Z> getParentPath() {
         return _parent;
     }

     /**
      * Gets the path that originates this traversal. Can be itself if this path is the root.
      */
     public PathImpl<?,?> getInnermostParentPath() {
         return (_parent == null) ? this : _parent.getInnermostParentPath();
     }

     /**
      * Gets the field that may have been embedded inside the given field.
      * For example, a given primary key field which is using an embedded class as a complex primary key.
      * @param fmd a given field
      * @return the embedded field or the given field itself
      */
     protected FieldMetaData getEmbeddedFieldMetaData(FieldMetaData fmd) {
         Members.Member<?,?> member = getInnermostMember(_parent,_member);

         ClassMetaData embeddedMeta = member.fmd.isElementCollection()
         		? member.fmd.getElement().getEmbeddedMetaData()
         		: member.fmd.getEmbeddedMetaData();

         return (embeddedMeta != null) ? embeddedMeta.getField(fmd.getName()) : fmd;
     }

     protected Members.Member<?,?> getInnermostMember(PathImpl<?,?> parent, Members.Member<?,?> member) {
         return member != null ? member : getInnermostMember(parent._parent,  parent._member);
     }

     /**
      * Makes this path correlated to the given path.
      */
     public void setCorrelatedPath(PathImpl<?,?> correlatedPath) {
         _correlatedPath = correlatedPath;
     }

     /**
      * Gets the path correlated to this path, if any.
      */
     public PathImpl<?,?> getCorrelatedPath() {
         return _correlatedPath;
     }

     /**
      * Affirms if this path is correlated to another path.
      */
     public boolean isCorrelated() {
         return _correlatedPath != null;
     }

     /**
      * Convert this path to a kernel path.
      */
     @Override
     public Value toValue(ExpressionFactory factory, CriteriaQueryImpl<?> q) {
         if (q.isRegistered(this))
             return q.getRegisteredValue(this);
         org.apache.openjpa.kernel.exps.Path path = null;
         SubqueryImpl<?> subquery = q.getDelegator();
         boolean allowNull = _parent == null ? false : _parent instanceof Join
             && ((Join<?,?>)_parent).getJoinType() != JoinType.INNER;
         PathImpl<?,?> corrJoin = getCorrelatedJoin(this);
         PathImpl<?,?> corrRoot = getCorrelatedRoot(subquery);
         if (_parent != null && q.isRegistered(_parent)) {
             path = factory.newPath(q.getRegisteredVariable(_parent));
             path.setSchemaAlias(q.getAlias(_parent));
             path.get(_member.fmd, allowNull);
         } else if (_parent != null && _parent._correlatedPath != null && q.isRegistered(_parent._correlatedPath)){
             path = factory.newPath(q.getRegisteredVariable(_parent._correlatedPath));
             path.setSchemaAlias(q.getAlias(_parent._correlatedPath));
             path.get(_member.fmd, allowNull);
         } else if (corrJoin != null || corrRoot != null) {
             org.apache.openjpa.kernel.exps.Subquery subQ = subquery.getSubQ();
             path = factory.newPath(subQ);
             path.setMetaData(subQ.getMetaData());
             path.setSchemaAlias(q.getAlias(_parent));
             traversePath(_parent, path, _member.fmd);
         } else if (_parent != null) {
             Value val = _parent.toValue(factory, q);
             if (val instanceof org.apache.openjpa.kernel.exps.Path) {
                 path = (org.apache.openjpa.kernel.exps.Path)val;
                 path.get(_member.fmd, allowNull);
             } else {
                 val.setAlias(q.getAlias(this));
                 return val;
             }
         } else if (_parent == null) {
             path = factory.newPath();
             path.setMetaData(q.getMetamodel().getRepository().getCachedMetaData(getJavaType()));
         }
         if (_member != null && !_member.isCollection()) {
             path.setImplicitType(getJavaType());
         }
         path.setAlias(q.getAlias(this));
         return path;
     }

     public PathImpl<?,?> getCorrelatedRoot(SubqueryImpl<?> subquery) {
         if (subquery == null)
             return null;
         PathImpl<?,?> root = getInnermostParentPath();
         if (subquery.getRoots() != null && subquery.getRoots().contains(this))
             return root;
         return null;
     }


     public PathImpl<?,?> getCorrelatedJoin(PathImpl<?,?> path) {
         if (path._correlatedPath != null)
             return path._correlatedPath;
         if (path._parent == null)
             return null;
         return getCorrelatedJoin(path._parent);
     }

     /**
      * Affirms if this receiver occurs in the roots of the given subquery.
      */
     public boolean inSubquery(SubqueryImpl<?> subquery) {
         return subquery != null && (subquery.getRoots() == null ? false : subquery.getRoots().contains(this));
     }

     protected void traversePath(PathImpl<?,?> parent,  org.apache.openjpa.kernel.exps.Path path, FieldMetaData fmd) {
         boolean allowNull = parent == null ? false : parent instanceof Join
             && ((Join<?,?>)parent).getJoinType() != JoinType.INNER;
         FieldMetaData fmd1 = parent._member == null ? null : parent._member.fmd;
         PathImpl<?,?> parent1 = parent._parent;
         if (parent1 == null || parent1.getCorrelatedPath() != null) {
             if (fmd != null)
                 path.get(fmd, allowNull);
             return;
         }
         traversePath(parent1, path, fmd1);
         if (fmd != null)
             path.get(fmd, allowNull);
     }

     /**
      *  Gets a new path that represents the given single-valued attribute from this path.
      */
     public <Y> Path<Y> get(SingularAttribute<? super X, Y> attr) {
     	if (getType() != attr.getDeclaringType()) {
     		attr = (SingularAttribute)((ManagedType)getType()).getAttribute(attr.getName());
     	}
         return new PathImpl<X,Y>(this, (Members.SingularAttributeImpl<? super X, Y>)attr, attr.getJavaType());
     }

     /**
      *  Gets a new path that represents the given multi-valued attribute from this path.
      */
     public <E, C extends java.util.Collection<E>> Expression<C>  get(PluralAttribute<X, C, E> coll) {
     	if (getType() != coll.getDeclaringType()) {
     		coll = (PluralAttribute)((ManagedType)getType()).getAttribute(coll.getName());
     	}
         return new PathImpl<X,C>(this, (Members.PluralAttributeImpl<? super X, C, E>)coll, coll.getJavaType());
     }

     /**
      *  Gets a new path that represents the given map-valued attribute from this path.
      */
     public <K, V, M extends java.util.Map<K, V>> Expression<M> get(MapAttribute<X, K, V> map) {
     	if (getType() != map.getDeclaringType()) {
     		map = (MapAttribute)((ManagedType)getType()).getAttribute(map.getName());
     	}
         return new PathImpl<X,M>(this, (Members.MapAttributeImpl<? super X,K,V>)map, (Class<M>)map.getJavaType());
     }

     /**
      * Gets a new path that represents the attribute of the given name from this path.
      *
      * @exception IllegalArgumentException if this path represents a basic attribute that is can not be traversed
      * further.
      */
     public <Y> Path<Y> get(String attName) {
         Type<?> type = this.getType();
         if (type.getPersistenceType() == PersistenceType.BASIC) {
             throw new IllegalArgumentException(this + " is a basic path and can not be navigated to " + attName);
         }

         Members.Member<? super X, Y> next = (Members.Member<? super X, Y>)
            ((ManagedType<? super X>)type).getAttribute(attName);
         return new PathImpl<X,Y>(this, next, next.getJavaType());
     }

     public Type<?> getType() {
         return _member.getType();
     }

     @SuppressWarnings("unchecked")
     public Member<? extends Z, X> getMember() {
         return (Member<? extends Z, X>) _member;
     }

     /**
      * Get the type() expression corresponding to this path.
      */
     public Expression<Class<? extends X>> type() {
         return new Expressions.Type<Class<? extends X>>(this);
     }

     public StringBuilder asValue(AliasContext q) {
         StringBuilder buffer = new StringBuilder();
         if (_parent != null) {
             Value var = q.getRegisteredVariable(_parent);
             buffer.append(var != null ? var.getName() : _parent.asValue(q)).append(".");
         }
         if (_member != null) {
             buffer.append(_member.fmd.getName());
         }
         return buffer;
     }

     public StringBuilder asVariable(AliasContext q) {
         Value var = q.getRegisteredVariable(this);
         return asValue(q).append(" ").append(var == null ? "?" : var.getName());
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*/

	package org.apache.openjpa.persistence.criteria;

	import javax.persistence.criteria.Expression;
	import javax.persistence.criteria.Join;
	import javax.persistence.criteria.JoinType;
	import javax.persistence.criteria.Path;
	import javax.persistence.metamodel.Bindable;
	import javax.persistence.metamodel.ManagedType;
	import javax.persistence.metamodel.MapAttribute;
	import javax.persistence.metamodel.PluralAttribute;
	import javax.persistence.metamodel.SingularAttribute;
	import javax.persistence.metamodel.Type;
	import javax.persistence.metamodel.Type.PersistenceType;

	import org.apache.openjpa.kernel.exps.ExpressionFactory;
	import org.apache.openjpa.kernel.exps.Value;
	import org.apache.openjpa.meta.ClassMetaData;
	import org.apache.openjpa.meta.FieldMetaData;
	import org.apache.openjpa.persistence.meta.Members;
	import org.apache.openjpa.persistence.meta.Members.Member;

	/**
	* Path is an expression representing a persistent attribute traversed from a parent path.
	* The type of the path is the type of the persistent attribute.
	* If the persistent attribute is bindable, then further path can be traversed from this path.
	*
	* @author Pinaki Poddar
	* @author Fay Wang
	*
	* @param <Z> the type of the parent path
	* @param <X> the type of this path
	*/
	class PathImpl<Z,X> extends ExpressionImpl<X> implements Path<X> {
	protected final PathImpl<?,Z> _parent;
	protected final Members.Member<? super Z,?> _member;
	private boolean isEmbedded = false;
	private PathImpl<?,?> _correlatedPath;

	/**
	* Protected constructor use by root path which neither represent a member nor has a parent.
	*/
	protected PathImpl(Class<X> cls) {
	super(cls);
	_parent = null;
	_member = null;
	}

	/**
	* Create a path from the given parent representing the given member.
	*
	* @param parent the path from which this path needs to be constructed. Must not be null.
	* @param member the persistent property that represents this path.
	* @param cls denotes the type expressed by this path.
	*/
	public PathImpl(PathImpl<?,Z> parent, Members.Member<? super Z, ?> member, Class<X> cls) {
	super(cls);
	_parent = parent;
	if (_parent.isEmbedded) {
	FieldMetaData fmd = getEmbeddedFieldMetaData(member.fmd);
	_member = new Members.SingularAttributeImpl(member.owner, fmd);
	} else {
	_member = member;
	}
	isEmbedded = _member.fmd.isElementCollection() ? _member.fmd.getElement().isEmbedded() :
	_member.fmd.isEmbedded();
	}

	/**
	* Gets the bindable object that corresponds to the path expression.
	*
	* @throws IllegalArgumentException if this path is not bindable
	*/
	public Bindable<X> getModel() {
	if (_member instanceof Bindable<?> == false) {
	throw new IllegalArgumentException(this + " represents a basic path and not a bindable");
	}
	return (Bindable<X>)_member;
	}

	/**
	* Gets the parent of this path or null if this path is the root.
	*/
	public final Path<Z> getParentPath() {
	return _parent;
	}

	/**
	* Gets the path that originates this traversal. Can be itself if this path is the root.
	*/
	public PathImpl<?,?> getInnermostParentPath() {
	return (_parent == null) ? this : _parent.getInnermostParentPath();
	}

	/**
	* Gets the field that may have been embedded inside the given field.
	* For example, a given primary key field which is using an embedded class as a complex primary key.
	* @param fmd a given field
	* @return the embedded field or the given field itself
	*/
	protected FieldMetaData getEmbeddedFieldMetaData(FieldMetaData fmd) {
	Members.Member<?,?> member = getInnermostMember(_parent,_member);

	ClassMetaData embeddedMeta = member.fmd.isElementCollection()
	? member.fmd.getElement().getEmbeddedMetaData()
	: member.fmd.getEmbeddedMetaData();

	return (embeddedMeta != null) ? embeddedMeta.getField(fmd.getName()) : fmd;
	}

	protected Members.Member<?,?> getInnermostMember(PathImpl<?,?> parent, Members.Member<?,?> member) {
	return member != null ? member : getInnermostMember(parent._parent, parent._member);
	}

	/**
	* Makes this path correlated to the given path.
	*/
	public void setCorrelatedPath(PathImpl<?,?> correlatedPath) {
	_correlatedPath = correlatedPath;
	}

	/**
	* Gets the path correlated to this path, if any.
	*/
	public PathImpl<?,?> getCorrelatedPath() {
	return _correlatedPath;
	}

	/**
	* Affirms if this path is correlated to another path.
	*/
	public boolean isCorrelated() {
	return _correlatedPath != null;
	}

	/**
	* Convert this path to a kernel path.
	*/
	@Override
	public Value toValue(ExpressionFactory factory, CriteriaQueryImpl<?> q) {
	if (q.isRegistered(this))
	return q.getRegisteredValue(this);
	org.apache.openjpa.kernel.exps.Path path = null;
	SubqueryImpl<?> subquery = q.getDelegator();
	boolean allowNull = _parent == null ? false : _parent instanceof Join
	&& ((Join<?,?>)_parent).getJoinType() != JoinType.INNER;
	PathImpl<?,?> corrJoin = getCorrelatedJoin(this);
	PathImpl<?,?> corrRoot = getCorrelatedRoot(subquery);
	if (_parent != null && q.isRegistered(_parent)) {
	path = factory.newPath(q.getRegisteredVariable(_parent));
	path.setSchemaAlias(q.getAlias(_parent));
	path.get(_member.fmd, allowNull);
	} else if (_parent != null && _parent._correlatedPath != null && q.isRegistered(_parent._correlatedPath)){
	path = factory.newPath(q.getRegisteredVariable(_parent._correlatedPath));
	path.setSchemaAlias(q.getAlias(_parent._correlatedPath));
	path.get(_member.fmd, allowNull);
	} else if (corrJoin != null \|\| corrRoot != null) {
	org.apache.openjpa.kernel.exps.Subquery subQ = subquery.getSubQ();
	path = factory.newPath(subQ);
	path.setMetaData(subQ.getMetaData());
	path.setSchemaAlias(q.getAlias(_parent));
	traversePath(_parent, path, _member.fmd);
	} else if (_parent != null) {
	Value val = _parent.toValue(factory, q);
	if (val instanceof org.apache.openjpa.kernel.exps.Path) {
	path = (org.apache.openjpa.kernel.exps.Path)val;
	path.get(_member.fmd, allowNull);
	} else {
	val.setAlias(q.getAlias(this));
	return val;
	}
	} else if (_parent == null) {
	path = factory.newPath();
	path.setMetaData(q.getMetamodel().getRepository().getCachedMetaData(getJavaType()));
	}
	if (_member != null && !_member.isCollection()) {
	path.setImplicitType(getJavaType());
	}
	path.setAlias(q.getAlias(this));
	return path;
	}

	public PathImpl<?,?> getCorrelatedRoot(SubqueryImpl<?> subquery) {
	if (subquery == null)
	return null;
	PathImpl<?,?> root = getInnermostParentPath();
	if (subquery.getRoots() != null && subquery.getRoots().contains(this))
	return root;
	return null;
	}


	public PathImpl<?,?> getCorrelatedJoin(PathImpl<?,?> path) {
	if (path._correlatedPath != null)
	return path._correlatedPath;
	if (path._parent == null)
	return null;
	return getCorrelatedJoin(path._parent);
	}

	/**
	* Affirms if this receiver occurs in the roots of the given subquery.
	*/
	public boolean inSubquery(SubqueryImpl<?> subquery) {
	return subquery != null && (subquery.getRoots() == null ? false : subquery.getRoots().contains(this));
	}

	protected void traversePath(PathImpl<?,?> parent, org.apache.openjpa.kernel.exps.Path path, FieldMetaData fmd) {
	boolean allowNull = parent == null ? false : parent instanceof Join
	&& ((Join<?,?>)parent).getJoinType() != JoinType.INNER;
	FieldMetaData fmd1 = parent._member == null ? null : parent._member.fmd;
	PathImpl<?,?> parent1 = parent._parent;
	if (parent1 == null \|\| parent1.getCorrelatedPath() != null) {
	if (fmd != null)
	path.get(fmd, allowNull);
	return;
	}
	traversePath(parent1, path, fmd1);
	if (fmd != null)
	path.get(fmd, allowNull);
	}

	/**
	* Gets a new path that represents the given single-valued attribute from this path.
	*/
	public <Y> Path<Y> get(SingularAttribute<? super X, Y> attr) {
	if (getType() != attr.getDeclaringType()) {
	attr = (SingularAttribute)((ManagedType)getType()).getAttribute(attr.getName());
	}
	return new PathImpl<X,Y>(this, (Members.SingularAttributeImpl<? super X, Y>)attr, attr.getJavaType());
	}

	/**
	* Gets a new path that represents the given multi-valued attribute from this path.
	*/
	public <E, C extends java.util.Collection<E>> Expression<C> get(PluralAttribute<X, C, E> coll) {
	if (getType() != coll.getDeclaringType()) {
	coll = (PluralAttribute)((ManagedType)getType()).getAttribute(coll.getName());
	}
	return new PathImpl<X,C>(this, (Members.PluralAttributeImpl<? super X, C, E>)coll, coll.getJavaType());
	}

	/**
	* Gets a new path that represents the given map-valued attribute from this path.
	*/
	public <K, V, M extends java.util.Map<K, V>> Expression<M> get(MapAttribute<X, K, V> map) {
	if (getType() != map.getDeclaringType()) {
	map = (MapAttribute)((ManagedType)getType()).getAttribute(map.getName());
	}
	return new PathImpl<X,M>(this, (Members.MapAttributeImpl<? super X,K,V>)map, (Class<M>)map.getJavaType());
	}

	/**
	* Gets a new path that represents the attribute of the given name from this path.
	*
	* @exception IllegalArgumentException if this path represents a basic attribute that is can not be traversed
	* further.
	*/
	public <Y> Path<Y> get(String attName) {
	Type<?> type = this.getType();
	if (type.getPersistenceType() == PersistenceType.BASIC) {
	throw new IllegalArgumentException(this + " is a basic path and can not be navigated to " + attName);
	}

	Members.Member<? super X, Y> next = (Members.Member<? super X, Y>)
	((ManagedType<? super X>)type).getAttribute(attName);
	return new PathImpl<X,Y>(this, next, next.getJavaType());
	}

	public Type<?> getType() {
	return _member.getType();
	}

	@SuppressWarnings("unchecked")
	public Member<? extends Z, X> getMember() {
	return (Member<? extends Z, X>) _member;
	}

	/**
	* Get the type() expression corresponding to this path.
	*/
	public Expression<Class<? extends X>> type() {
	return new Expressions.Type<Class<? extends X>>(this);
	}

	public StringBuilder asValue(AliasContext q) {
	StringBuilder buffer = new StringBuilder();
	if (_parent != null) {
	Value var = q.getRegisteredVariable(_parent);
	buffer.append(var != null ? var.getName() : _parent.asValue(q)).append(".");
	}
	if (_member != null) {
	buffer.append(_member.fmd.getName());
	}
	return buffer;
	}

	public StringBuilder asVariable(AliasContext q) {
	Value var = q.getRegisteredVariable(this);
	return asValue(q).append(" ").append(var == null ? "?" : var.getName());
	}
	}