Spring Framework example source code file (JndiTemplate.java)

This example Spring Framework source code file (JndiTemplate.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

context, hashtable, initialcontext, jndi, jndi, jndicallback, jnditemplate, naming, namingexception, namingexception, object, object, properties, string, string, util

The Spring Framework JndiTemplate.java source code

/*
 * Copyright 2002-2007 the original author or authors.
 *
 * Licensed 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.springframework.jndi;

import java.util.Hashtable;
import java.util.Properties;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NameNotFoundException;
import javax.naming.NamingException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.util.CollectionUtils;

/**
 * Helper class that simplifies JNDI operations. It provides methods to lookup and
 * bind objects, and allows implementations of the {@link JndiCallback} interface
 * to perform any operation they like with a JNDI naming context provided.
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @see JndiCallback
 * @see #execute
 */
public class JndiTemplate {
	
	protected final Log logger = LogFactory.getLog(getClass());

	private Properties environment;


	/**
	 * Create a new JndiTemplate instance.
	 */
	public JndiTemplate() {
	}

	/**
	 * Create a new JndiTemplate instance, using the given environment.
	 */
	public JndiTemplate(Properties environment) {
		this.environment = environment;
	}


	/**
	 * Set the environment for the JNDI InitialContext.
	 */
	public void setEnvironment(Properties environment) {
		this.environment = environment;
	}

	/**
	 * Return the environment for the JNDI InitialContext, if any.
	 */
	public Properties getEnvironment() {
		return this.environment;
	}


	/**
	 * Execute the given JNDI context callback implementation.
	 * @param contextCallback JndiCallback implementation
	 * @return a result object returned by the callback, or <code>null
	 * @throws NamingException thrown by the callback implementation
	 * @see #createInitialContext
	 */
	public Object execute(JndiCallback contextCallback) throws NamingException {
		Context ctx = createInitialContext();
		try {
			return contextCallback.doInContext(ctx);
		}
		finally {
			try {
				ctx.close();
			}
			catch (NamingException ex) {
				logger.debug("Could not close JNDI InitialContext", ex);
			}
		}
	}

	/**
	 * Create a new JNDI initial context. Invoked by {@link #execute}.
	 * <p>The default implementation use this template's environment settings.
	 * Can be subclassed for custom contexts, e.g. for testing.
	 * @return the initial Context instance
	 * @throws NamingException in case of initialization errors
	 */
	protected Context createInitialContext() throws NamingException {
		Properties env = getEnvironment();
		Hashtable icEnv = null;
		if (env != null) {
			icEnv = new Hashtable(env.size());
			CollectionUtils.mergePropertiesIntoMap(env, icEnv);
		}
		return new InitialContext(icEnv);
	}


	/**
	 * Look up the object with the given name in the current JNDI context.
	 * @param name the JNDI name of the object
	 * @return object found (cannot be <code>null; if a not so well-behaved
	 * JNDI implementations returns null, a NamingException gets thrown)
	 * @throws NamingException if there is no object with the given
	 * name bound to JNDI
	 */
	public Object lookup(final String name) throws NamingException {
		if (logger.isDebugEnabled()) {
			logger.debug("Looking up JNDI object with name [" + name + "]");
		}
		return execute(new JndiCallback() {
			public Object doInContext(Context ctx) throws NamingException {
				Object located = ctx.lookup(name);
				if (located == null) {
					throw new NameNotFoundException(
							"JNDI object with [" + name + "] not found: JNDI implementation returned null");
				}
				return located;
			}
		});
	}

	/**
	 * Look up the object with the given name in the current JNDI context.
	 * @param name the JNDI name of the object
	 * @param requiredType type the JNDI object must match. Can be an interface or
	 * superclass of the actual class, or <code>null for any match. For example,
	 * if the value is <code>Object.class, this method will succeed whatever
	 * the class of the returned instance.
	 * @return object found (cannot be <code>null; if a not so well-behaved
	 * JNDI implementations returns null, a NamingException gets thrown)
	 * @throws NamingException if there is no object with the given
	 * name bound to JNDI
	 */
	public Object lookup(String name, Class requiredType) throws NamingException {
		Object jndiObject = lookup(name);
		if (requiredType != null && !requiredType.isInstance(jndiObject)) {
			throw new TypeMismatchNamingException(
					name, requiredType, (jndiObject != null ? jndiObject.getClass() : null));
		}
		return jndiObject;
	}

	/**
	 * Bind the given object to the current JNDI context, using the given name.
	 * @param name the JNDI name of the object
	 * @param object the object to bind
	 * @throws NamingException thrown by JNDI, mostly name already bound
	 */
	public void bind(final String name, final Object object) throws NamingException {
		if (logger.isDebugEnabled()) {
			logger.debug("Binding JNDI object with name [" + name + "]");
		}
		execute(new JndiCallback() {
			public Object doInContext(Context ctx) throws NamingException {
				ctx.bind(name, object);
				return null;
			}
		});
	}
	
	/**
	 * Rebind the given object to the current JNDI context, using the given name.
	 * Overwrites any existing binding.
	 * @param name the JNDI name of the object
	 * @param object the object to rebind
	 * @throws NamingException thrown by JNDI
	 */
	public void rebind(final String name, final Object object) throws NamingException {
		if (logger.isDebugEnabled()) {
			logger.debug("Rebinding JNDI object with name [" + name + "]");
		}
		execute(new JndiCallback() {
			public Object doInContext(Context ctx) throws NamingException {
				ctx.rebind(name, object);
				return null;
			}
		});
	}

	/**
	 * Remove the binding for the given name from the current JNDI context.
	 * @param name the JNDI name of the object
	 * @throws NamingException thrown by JNDI, mostly name not found
	 */
	public void unbind(final String name) throws NamingException {
		if (logger.isDebugEnabled()) {
			logger.debug("Unbinding JNDI object with name [" + name + "]");
		}
		execute(new JndiCallback() {
			public Object doInContext(Context ctx) throws NamingException {
				ctx.unbind(name);
				return null;
			}
		});
	}
	
}