001/* 002 * Copyright 2012-2017 the original author or authors. 003 * 004 * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0 009 * 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 */ 016 017package org.springframework.boot.jdbc.metadata; 018 019import javax.sql.DataSource; 020 021/** 022 * Provides access meta-data that is commonly available from most pooled 023 * {@link DataSource} implementations. 024 * 025 * @author Stephane Nicoll 026 * @since 2.0.0 027 */ 028public interface DataSourcePoolMetadata { 029 030 /** 031 * Return the usage of the pool as value between 0 and 1 (or -1 if the pool is not 032 * limited). 033 * <ul> 034 * <li>1 means that the maximum number of connections have been allocated</li> 035 * <li>0 means that no connection is currently active</li> 036 * <li>-1 means there is not limit to the number of connections that can be allocated 037 * </li> 038 * </ul> 039 * This may also return {@code null} if the data source does not provide the necessary 040 * information to compute the poll usage. 041 * @return the usage value or {@code null} 042 */ 043 Float getUsage(); 044 045 /** 046 * Return the current number of active connections that have been allocated from the 047 * data source or {@code null} if that information is not available. 048 * @return the number of active connections or {@code null} 049 */ 050 Integer getActive(); 051 052 /** 053 * Return the maximum number of active connections that can be allocated at the same 054 * time or {@code -1} if there is no limit. Can also return {@code null} if that 055 * information is not available. 056 * @return the maximum number of active connections or {@code null} 057 */ 058 Integer getMax(); 059 060 /** 061 * Return the minimum number of idle connections in the pool or {@code null} if that 062 * information is not available. 063 * @return the minimum number of active connections or {@code null} 064 */ 065 Integer getMin(); 066 067 /** 068 * Return the query to use to validate that a connection is valid or {@code null} if 069 * that information is not available. 070 * @return the validation query or {@code null} 071 */ 072 String getValidationQuery(); 073 074 /** 075 * The default auto-commit state of connections created by this pool. If not set 076 * ({@code null}), default is JDBC driver default (If set to null then the 077 * java.sql.Connection.setAutoCommit(boolean) method will not be called.) 078 * @return the default auto-commit state or {@code null} 079 */ 080 Boolean getDefaultAutoCommit(); 081 082}