AbstractFilterBuilder.java

/**
 *  Copyright 2012 Universitat Pompeu Fabra.
 *
 *  Licensed 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.onexus.collection.store.sql.filters;

import org.onexus.collection.api.query.Filter;
import org.onexus.collection.api.query.Query;
import org.onexus.collection.store.sql.SqlCollectionStore;
import org.onexus.collection.store.sql.SqlDialect;
import org.onexus.collection.store.sql.adapters.SqlAdapter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public abstract class AbstractFilterBuilder<T extends Filter> implements FilterBuilder {

    private static final Logger log = LoggerFactory.getLogger(AbstractFilterBuilder.class);
    private Class<T> filterClass;

    private SqlDialect dialect;

    public AbstractFilterBuilder(SqlDialect dialect, Class<T> filterClass) {
        this.filterClass = filterClass;
        this.dialect = dialect;
    }

    protected SqlDialect getDialect() {
        return this.dialect;
    }

    @Override
    public boolean canBuild(Filter filter) {

        if (filter == null) {
            return false;
        }

        return filterClass.isAssignableFrom(filter.getClass());
    }

    @Override
    public void build(SqlCollectionStore store, Query query, StringBuilder where, Filter filter) {
        innerBuild(store, query, where, (T) filter);
    }

    protected void encodeValue(StringBuilder oql, Class<?> type, Object value) {

        SqlAdapter adapter = dialect.getAdapter(type);

        try {
            adapter.append(oql, value);
        } catch (Exception e) {
            String msg = "Error encoding value '" + value + "' as " + type.getSimpleName() + "";
            log.error(msg);
            log.error(e.getMessage());
            throw new RuntimeException(msg, e);
        }

    }

    protected abstract void innerBuild(SqlCollectionStore store, Query query, StringBuilder where, T filter);

}