Hibernate example source code file (BinaryArithmeticOperation.java)

This example Hibernate source code file (BinaryArithmeticOperation.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Hibernate tags/keywords

binaryarithmeticoperation, class, class, criteriabuilderimpl, expression, io, literalexpression, n, n, number, number, operation, right_paren, string, string

The Hibernate BinaryArithmeticOperation.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2009 by Red Hat Inc and/or its affiliates or by
 * third-party contributors as indicated by either @author tags or express
 * copyright attribution statements applied by the authors.  All
 * third-party contributions are distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.ejb.criteria.expression;
import java.io.Serializable;
import javax.persistence.criteria.Expression;
import org.hibernate.ejb.criteria.CriteriaBuilderImpl;
import org.hibernate.ejb.criteria.CriteriaQueryCompiler;
import org.hibernate.ejb.criteria.ParameterRegistry;
import org.hibernate.ejb.criteria.Renderable;
import org.hibernate.ejb.criteria.predicate.ImplicitNumericExpressionTypeDeterminer;

/**
 * Models standard arithmetc operations with two operands.
 *
 * @author Steve Ebersole
 */
public class BinaryArithmeticOperation<N extends Number>
		extends ExpressionImpl<N>
		implements BinaryOperatorExpression<N>, Serializable {

	public static enum Operation {
		ADD {
			String apply(String lhs, String rhs) {
				return applyPrimitive( lhs, '+', rhs );
			}
		},
		SUBTRACT {
			String apply(String lhs, String rhs) {
				return applyPrimitive( lhs, '-', rhs );
			}
		},
		MULTIPLY {
			String apply(String lhs, String rhs) {
				return applyPrimitive( lhs, '*', rhs );
			}
		},
		DIVIDE {
			String apply(String lhs, String rhs) {
				return applyPrimitive( lhs, '/', rhs );
			}
		},
		QUOT {
			String apply(String lhs, String rhs) {
				return applyPrimitive( lhs, '/', rhs );
			}
		},
		MOD {
			String apply(String lhs, String rhs) {
//				return lhs + " % " + rhs;
				return "mod(" + lhs + "," + rhs + ")";
			}
		};
		abstract String apply(String lhs, String rhs);

		private static final char LEFT_PAREN = '(';
		private static final char RIGHT_PAREN = ')';
		private static String applyPrimitive(String lhs, char operator, String rhs) {
			return new StringBuffer( lhs.length() + rhs.length() + 3 )
					.append( LEFT_PAREN )
					.append( lhs )
					.append( operator )
					.append( rhs )
					.append( RIGHT_PAREN )
					.toString();
		}
	}

	private final Operation operator;
	private final Expression<? extends N> rhs;
	private final Expression<? extends N> lhs;

	public static Class<? extends Number> determineResultType(
			Class<? extends Number> argument1Type,
			Class<? extends Number> argument2Type
	) {
		return determineResultType( argument1Type, argument2Type, false );
	}

	public static Class<? extends Number> determineResultType(
			Class<? extends Number> argument1Type,
			Class<? extends Number> argument2Type,
			boolean isQuotientOperation
	) {
		if ( isQuotientOperation ) {
			return Number.class;
		}
		return ImplicitNumericExpressionTypeDeterminer.determineResultType( argument1Type, argument2Type );
	}

	/**
	 * Helper for determining the appropriate operation return type based on one of the operands as an expression.
	 *
	 * @param defaultType The default return type to use if we cannot determine the java type of 'expression' operand.
	 * @param expression The operand.
	 *
	 * @return The appropriate return type.
	 */
	public static Class<? extends Number> determineReturnType(
			Class<? extends Number> defaultType,
			Expression<? extends Number> expression) {
		return expression == null || expression.getJavaType() == null 
				? defaultType
				: expression.getJavaType();
	}

	/**
	 * Helper for determining the appropriate operation return type based on one of the operands as a literal.
	 *
	 * @param defaultType The default return type to use if we cannot determine the java type of 'numberLiteral' operand.
	 * @param numberLiteral The operand.
	 *
	 * @return The appropriate return type.
	 */
	public static Class<? extends Number> determineReturnType(
			Class<? extends Number> defaultType,
			Number numberLiteral) {
		return numberLiteral == null ? defaultType : numberLiteral.getClass();
	}

	/**
	 * Creates an arithmethic operation based on 2 expressions.
	 *
	 * @param criteriaBuilder The builder for query components.
	 * @param resultType The operation result type
	 * @param operator The operator (type of operation).
	 * @param lhs The left-hand operand.
	 * @param rhs The right-hand operand
	 */
	public BinaryArithmeticOperation(
			CriteriaBuilderImpl criteriaBuilder,
			Class<N> resultType,
			Operation operator,
			Expression<? extends N> lhs,
			Expression<? extends N> rhs) {
		super( criteriaBuilder, resultType );
		this.operator = operator;
		this.lhs = lhs;
		this.rhs = rhs;
	}

	/**
	 * Creates an arithmethic operation based on an expression and a literal.
	 *
	 * @param criteriaBuilder The builder for query components.
	 * @param javaType The operation result type
	 * @param operator The operator (type of operation).
	 * @param lhs The left-hand operand
	 * @param rhs The right-hand operand (the literal)
	 */
	public BinaryArithmeticOperation(
			CriteriaBuilderImpl criteriaBuilder,
			Class<N> javaType,
			Operation operator,
			Expression<? extends N> lhs,
			N rhs) {
		super( criteriaBuilder, javaType );
		this.operator = operator;
		this.lhs = lhs;
		this.rhs = new LiteralExpression<N>( criteriaBuilder, rhs );
	}

	/**
	 * Creates an arithmetic operation based on an expression and a literal.
	 *
	 * @param criteriaBuilder The builder for query components.
	 * @param javaType The operation result type
	 * @param operator The operator (type of operation).
	 * @param lhs The left-hand operand (the literal)
	 * @param rhs The right-hand operand
	 */
	public BinaryArithmeticOperation(
			CriteriaBuilderImpl criteriaBuilder,
			Class<N> javaType,
			Operation operator,
			N lhs,
			Expression<? extends N> rhs) {
		super( criteriaBuilder, javaType );
		this.operator = operator;
		this.lhs = new LiteralExpression<N>( criteriaBuilder, lhs );
		this.rhs = rhs;
	}
	public Operation getOperator() {
		return operator;
	}

	/**
	 * {@inheritDoc}
	 */
	public Expression<? extends N> getRightHandOperand() {
		return rhs;
	}

	/**
	 * {@inheritDoc}
	 */
	public Expression<? extends N> getLeftHandOperand() {
		return lhs;
	}

	/**
	 * {@inheritDoc}
	 */
	public void registerParameters(ParameterRegistry registry) {
		Helper.possibleParameter( getRightHandOperand(), registry );
		Helper.possibleParameter( getLeftHandOperand(), registry );
	}

	public String render(CriteriaQueryCompiler.RenderingContext renderingContext) {
		return getOperator().apply(
				( (Renderable) getLeftHandOperand() ).render( renderingContext ),
				( (Renderable) getRightHandOperand() ).render( renderingContext )
		);
	}

	public String renderProjection(CriteriaQueryCompiler.RenderingContext renderingContext) {
		return render( renderingContext );
	}
}