001/**
002 * Copyright 2005-2016 The Kuali Foundation
003 *
004 * Licensed under the Educational Community License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.opensource.org/licenses/ecl2.php
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.kuali.rice.web.health;
017
018import com.codahale.metrics.Gauge;
019import com.codahale.metrics.health.HealthCheck;
020import org.kuali.rice.core.framework.persistence.platform.DatabasePlatform;
021import org.springframework.jdbc.core.JdbcTemplate;
022
023import javax.sql.DataSource;
024
025/**
026 * A combination of health check and gauge which will check for successful connection to the given {@link DataSource}
027 * using the validation query defined on the given {@link DatabasePlatform}.
028 *
029 * @author Eric Westfall
030 */
031public class DatabaseConnectionHealthGauge extends HealthCheck implements Gauge<Boolean> {
032
033    private final DataSource dataSource;
034    private final DatabasePlatform platform;
035
036    public DatabaseConnectionHealthGauge(DataSource dataSource, DatabasePlatform platform) {
037        this.dataSource = dataSource;
038        this.platform = platform;
039    }
040
041    @Override
042    public Boolean getValue() {
043        Result result = execute();
044        return result.isHealthy();
045    }
046
047    @Override
048    protected Result check() throws Exception {
049        JdbcTemplate template = new JdbcTemplate(dataSource);
050        template.execute(platform.getValidationQuery());
051        // if it's unhealthy, above method will throw an exception
052        return Result.healthy();
053    }
054
055}