Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF 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 * * 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.apache.commons.dbcp2; import java.sql.Connection; import java.sql.ResultSet; import java.sql.Statement; import java.text.MessageFormat; import java.util.HashSet; import java.util.ResourceBundle; import java.util.Set; /** * Utility methods. * @version $Id: Utils.java 1680126 2015-05-18 23:22:01Z ggregory $ * @since 2.0 */ public final class Utils { private static final ResourceBundle messages = ResourceBundle .getBundle(Utils.class.getPackage().getName() + ".LocalStrings"); public static final boolean IS_SECURITY_ENABLED = System.getSecurityManager() != null; /** Any SQL_STATE starting with this value is considered a fatal disconnect */ public static final String DISCONNECTION_SQL_CODE_PREFIX = "08"; /** * SQL codes of fatal connection errors. * <ul> * <li>57P01 (ADMIN SHUTDOWN)</li> * <li>57P02 (CRASH SHUTDOWN)</li> * <li>57P03 (CANNOT CONNECT NOW)</li> * <li>01002 (SQL92 disconnect error)</li> * <li>JZ0C0 (Sybase disconnect error)</li> * <li>JZ0C1 (Sybase disconnect error)</li> * </ul> */ public static final Set<String> DISCONNECTION_SQL_CODES; static { DISCONNECTION_SQL_CODES = new HashSet<>(); DISCONNECTION_SQL_CODES.add("57P01"); // ADMIN SHUTDOWN DISCONNECTION_SQL_CODES.add("57P02"); // CRASH SHUTDOWN DISCONNECTION_SQL_CODES.add("57P03"); // CANNOT CONNECT NOW DISCONNECTION_SQL_CODES.add("01002"); // SQL92 disconnect error DISCONNECTION_SQL_CODES.add("JZ0C0"); // Sybase disconnect error DISCONNECTION_SQL_CODES.add("JZ0C1"); // Sybase disconnect error } private Utils() { // not instantiable } /** * Closes the ResultSet (which may be null). * * @param rset a ResultSet, may be {@code null} */ public static void closeQuietly(ResultSet rset) { if (rset != null) { try { rset.close(); } catch (Exception e) { // ignored } } } /** * Closes the Connection (which may be null). * * @param conn a Connection, may be {@code null} */ public static void closeQuietly(Connection conn) { if (conn != null) { try { conn.close(); } catch (Exception e) { // ignored } } } /** * Closes the Statement (which may be null). * * @param stmt a Statement, may be {@code null} */ public static void closeQuietly(Statement stmt) { if (stmt != null) { try { stmt.close(); } catch (Exception e) { // ignored } } } /** * Obtain the correct i18n message for the given key. */ public static String getMessage(String key) { return getMessage(key, (Object[]) null); } /** * Obtain the correct i18n message for the given key with placeholders * replaced by the supplied arguments. */ public static String getMessage(String key, Object... args) { String msg = messages.getString(key); if (args == null || args.length == 0) { return msg; } MessageFormat mf = new MessageFormat(msg); return mf.format(args, new StringBuffer(), null).toString(); } }