is.codion.common.db.report.AbstractReport Maven / Gradle / Ivy

Go to download
/*
 * This file is part of Codion.
 *
 * Codion is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Codion 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Codion.  If not, see .
 *
 * Copyright (c) 2020 - 2024, Björn Darri Sigurðsson.
 */
package is.codion.common.db.report;

import static java.util.Objects.requireNonNull;

/**
 * A base class for wrapping reports, handles caching.
 * @param  the report type
 * @param  the report result type
 * @param  the report parameters type
 */
public abstract class AbstractReport implements Report {

	/**
	 * The path of this report, relative to any defined #{@link Report#REPORT_PATH}.
	 */
	protected final String reportPath;

	private final boolean cacheReport;

	private T cachedReport;

	/**
	 * Instantiates a new AbstractReport.
	 * @param reportPath the report path, relative to the central report path {@link Report#REPORT_PATH}.
	 * @param cacheReport true if the report should be cached when loaded
	 */
	protected AbstractReport(String reportPath, boolean cacheReport) {
		this.reportPath = requireNonNull(reportPath);
		this.cacheReport = cacheReport;
	}

	@Override
	public final String toString() {
		return fullReportPath();
	}

	@Override
	public final boolean equals(Object obj) {
		return obj instanceof AbstractReport && ((AbstractReport) obj).fullReportPath().equals(fullReportPath());
	}

	@Override
	public final int hashCode() {
		return fullReportPath().hashCode();
	}

	@Override
	public final synchronized boolean cached() {
		return cachedReport != null;
	}

	@Override
	public final synchronized void clearCache() {
		cachedReport = null;
	}

	/**
	 * This default implementation uses {@link Report#fullReportPath(String)}.
	 * @return a unique path for this report
	 */
	protected String fullReportPath() {
		return Report.fullReportPath(reportPath);
	}

	/**
	 * Returns the underlying report, either from the cache, if enabled or via {@link #load()}.
	 * @return the report
	 * @throws ReportException in case of an exception
	 * @see Report#CACHE_REPORTS
	 */
	protected final T loadAndCacheReport() {
		if (cacheReport) {
			return cachedReport();
		}

		return load();
	}

	private synchronized T cachedReport() {
		if (cachedReport == null) {
			cachedReport = load();
		}

		return cachedReport;
	}
}