CommonDatabaseWhereOp.java

/*
 * This file is part of DLect. DLect is a suite of code that facilitates the downloading of lecture recordings.
 *
 * Copyright © 2014 Lee Symes.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.dlect.helpers;

import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.Expression;
import javax.persistence.criteria.Path;

public class CommonDatabaseWhereOp {

    private static final DatabaseWhereOp<Object> EQUAL = new DatabaseWhereOp<Object>() {

        @Override
        public Expression<Boolean> getWhere(CriteriaBuilder cb, Path<Object> path, Object val) {
            return cb.equal(path, val);
        }

    };
    private static final DatabaseWhereOp<String> LIKE = new DatabaseWhereOp<String>() {

        @Override
        public Expression<Boolean> getWhere(CriteriaBuilder cb, Path<String> path, String val) {
            return cb.like(cb.lower(path), val.toLowerCase());
        }

    };

    @SuppressWarnings("unchecked")
    public static final <T> DatabaseWhereOp<T> equal() {
        return (DatabaseWhereOp<T>) EQUAL;
    }

    public static final DatabaseWhereOp<String> like() {
        return LIKE;
    }

    private CommonDatabaseWhereOp() {
    }

}