org.hibernate.criterion.AggregateProjection.java Source code

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Here is the source code for org.hibernate.criterion.AggregateProjection.java

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/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.criterion;

import java.util.Collections;
import java.util.List;

import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.dialect.function.SQLFunction;
import org.hibernate.type.Type;

/**
 * Base class for standard aggregation functions.
 *
 * @author max
 */
public class AggregateProjection extends SimpleProjection {
    protected final String propertyName;
    private final String functionName;

    protected AggregateProjection(String functionName, String propertyName) {
        this.functionName = functionName;
        this.propertyName = propertyName;
    }

    public String getFunctionName() {
        return functionName;
    }

    public String getPropertyName() {
        return propertyName;
    }

    @Override
    public Type[] getTypes(Criteria criteria, CriteriaQuery criteriaQuery) throws HibernateException {
        return new Type[] { getFunction(criteriaQuery)
                .getReturnType(criteriaQuery.getType(criteria, getPropertyName()), criteriaQuery.getFactory()) };
    }

    @Override
    public String toSqlString(Criteria criteria, int loc, CriteriaQuery criteriaQuery) throws HibernateException {
        final String functionFragment = getFunction(criteriaQuery).render(
                criteriaQuery.getType(criteria, getPropertyName()),
                buildFunctionParameterList(criteria, criteriaQuery), criteriaQuery.getFactory());
        return functionFragment + " as y" + loc + '_';
    }

    protected SQLFunction getFunction(CriteriaQuery criteriaQuery) {
        return getFunction(getFunctionName(), criteriaQuery);
    }

    protected SQLFunction getFunction(String functionName, CriteriaQuery criteriaQuery) {
        final SQLFunction function = criteriaQuery.getFactory().getSqlFunctionRegistry()
                .findSQLFunction(functionName);
        if (function == null) {
            throw new HibernateException("Unable to locate mapping for function named [" + functionName + "]");
        }
        return function;
    }

    protected List buildFunctionParameterList(Criteria criteria, CriteriaQuery criteriaQuery) {
        return buildFunctionParameterList(criteriaQuery.getColumn(criteria, getPropertyName()));
    }

    protected List buildFunctionParameterList(String column) {
        return Collections.singletonList(column);
    }

    @Override
    public String toString() {
        return functionName + "(" + propertyName + ')';
    }

}