Java tutorial
/* * Licensed to Jasig under one or more contributor license * agreements. See the NOTICE file distributed with this work * for additional information regarding copyright ownership. * Jasig licenses this file to you 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 the following location: * * 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.jasig.cas.monitor; import java.sql.ResultSet; import java.sql.SQLException; import javax.sql.DataSource; import javax.validation.constraints.NotNull; import org.springframework.dao.DataAccessException; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.jdbc.core.ResultSetExtractor; /** * Monitors a data source that describes a single connection or connection pool to a database. * * @author Marvin S. Addison * @since 3.5.1 */ public class DataSourceMonitor extends AbstractPoolMonitor { @NotNull private final JdbcTemplate jdbcTemplate; @NotNull private String validationQuery; /** * Creates a new instance that monitors the given data source. * * @param dataSource Data source to monitor. */ public DataSourceMonitor(final DataSource dataSource) { this.jdbcTemplate = new JdbcTemplate(dataSource); } /** * Sets the validation query used to monitor the data source. The validation query should return * at least one result; otherwise results are ignored. * * @param query Validation query that should be as efficient as possible. */ public void setValidationQuery(final String query) { this.validationQuery = query; } @Override protected StatusCode checkPool() throws Exception { return this.jdbcTemplate.query(this.validationQuery, new ResultSetExtractor<StatusCode>() { public StatusCode extractData(final ResultSet rs) throws SQLException, DataAccessException { if (rs.next()) { return StatusCode.OK; } return StatusCode.WARN; } }); } @Override protected int getIdleCount() { return PoolStatus.UNKNOWN_COUNT; } @Override protected int getActiveCount() { return PoolStatus.UNKNOWN_COUNT; } }