001/*
002 * Copyright 2002-2016 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 *      https://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.jndi;
018
019import javax.naming.InitialContext;
020import javax.naming.NamingException;
021
022import org.springframework.core.SpringProperties;
023import org.springframework.lang.Nullable;
024
025/**
026 * {@link JndiLocatorSupport} subclass with public lookup methods,
027 * for convenient use as a delegate.
028 *
029 * @author Juergen Hoeller
030 * @since 3.0.1
031 */
032public class JndiLocatorDelegate extends JndiLocatorSupport {
033
034        /**
035         * System property that instructs Spring to ignore a default JNDI environment, i.e.
036         * to always return {@code false} from {@link #isDefaultJndiEnvironmentAvailable()}.
037         * <p>The default is "false", allowing for regular default JNDI access e.g. in
038         * {@link JndiPropertySource}. Switching this flag to {@code true} is an optimization
039         * for scenarios where nothing is ever to be found for such JNDI fallback searches
040         * to begin with, avoiding the repeated JNDI lookup overhead.
041         * <p>Note that this flag just affects JNDI fallback searches, not explicitly configured
042         * JNDI lookups such as for a {@code DataSource} or some other environment resource.
043         * The flag literally just affects code which attempts JNDI searches based on the
044         * {@code JndiLocatorDelegate.isDefaultJndiEnvironmentAvailable()} check: in particular,
045         * {@code StandardServletEnvironment} and {@code StandardPortletEnvironment}.
046         * @since 4.3
047         * @see #isDefaultJndiEnvironmentAvailable()
048         * @see JndiPropertySource
049         */
050        public static final String IGNORE_JNDI_PROPERTY_NAME = "spring.jndi.ignore";
051
052
053        private static final boolean shouldIgnoreDefaultJndiEnvironment =
054                        SpringProperties.getFlag(IGNORE_JNDI_PROPERTY_NAME);
055
056
057        @Override
058        public Object lookup(String jndiName) throws NamingException {
059                return super.lookup(jndiName);
060        }
061
062        @Override
063        public <T> T lookup(String jndiName, @Nullable Class<T> requiredType) throws NamingException {
064                return super.lookup(jndiName, requiredType);
065        }
066
067
068        /**
069         * Configure a {@code JndiLocatorDelegate} with its "resourceRef" property set to
070         * {@code true}, meaning that all names will be prefixed with "java:comp/env/".
071         * @see #setResourceRef
072         */
073        public static JndiLocatorDelegate createDefaultResourceRefLocator() {
074                JndiLocatorDelegate jndiLocator = new JndiLocatorDelegate();
075                jndiLocator.setResourceRef(true);
076                return jndiLocator;
077        }
078
079        /**
080         * Check whether a default JNDI environment, as in a Java EE environment,
081         * is available on this JVM.
082         * @return {@code true} if a default InitialContext can be used,
083         * {@code false} if not
084         */
085        public static boolean isDefaultJndiEnvironmentAvailable() {
086                if (shouldIgnoreDefaultJndiEnvironment) {
087                        return false;
088                }
089                try {
090                        new InitialContext().getEnvironment();
091                        return true;
092                }
093                catch (Throwable ex) {
094                        return false;
095                }
096        }
097
098}