basedircontext.java

业界著名的tomcat服务器的最新6.0的源代码。

/*
 * 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.naming.resources;

import java.util.Hashtable;

import javax.naming.Context;
import javax.naming.Name;
import javax.naming.NameParser;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.Attributes;
import javax.naming.directory.DirContext;
import javax.naming.directory.ModificationItem;
import javax.naming.directory.SearchControls;

import org.apache.naming.NameParserImpl;
import org.apache.naming.StringManager;

/**
 * Directory Context implementation helper class.
 *
 * @author Remy Maucherat
 * @version $Revision: 467222 $ $Date: 2006-10-24 05:17:11 +0200 (mar., 24 oct. 2006) $
 */

public abstract class BaseDirContext implements DirContext {


    // -------------------------------------------------------------- Constants


    // ----------------------------------------------------------- Constructors


    /**
     * Builds a base directory context.
     */
    public BaseDirContext() {
        this.env = new Hashtable();
    }


    /**
     * Builds a base directory context using the given environment.
     */
    public BaseDirContext(Hashtable env) {
        this.env = env;
    }


    // ----------------------------------------------------- Instance Variables


    /**
     * The document base path.
     */
    protected String docBase = null;


    /**
     * Environment.
     */
    protected Hashtable env;


    /**
     * The string manager for this package.
     */
    protected StringManager sm = StringManager.getManager(Constants.Package);


    /**
     * Name parser for this context.
     */
    protected final NameParser nameParser = new NameParserImpl();


    /**
     * Cached.
     */
    protected boolean cached = true;


    /**
     * Cache TTL.
     */
    protected int cacheTTL = 5000; // 5s


    /**
     * Max size of resources which will have their content cached.
     */
    protected int cacheMaxSize = 10240; // 10 MB


    // ------------------------------------------------------------- Properties


    /**
     * Return the document root for this component.
     */
    public String getDocBase() {
        return (this.docBase);
    }


    /**
     * Set the document root for this component.
     *
     * @param docBase The new document root
     *
     * @exception IllegalArgumentException if the specified value is not
     *  supported by this implementation
     * @exception IllegalArgumentException if this would create a
     *  malformed URL
     */
    public void setDocBase(String docBase) {

        // Validate the format of the proposed document root
        if (docBase == null)
            throw new IllegalArgumentException
                (sm.getString("resources.null"));

        // Change the document root property
        this.docBase = docBase;

    }


    /**
     * Set cached.
     */
    public void setCached(boolean cached) {
        this.cached = cached;
    }


    /**
     * Is cached ?
     */
    public boolean isCached() {
        return cached;
    }


    /**
     * Set cache TTL.
     */
    public void setCacheTTL(int cacheTTL) {
        this.cacheTTL = cacheTTL;
    }


    /**
     * Get cache TTL.
     */
    public int getCacheTTL() {
        return cacheTTL;
    }


    /**
     * Return the maximum size of the cache in KB.
     */
    public int getCacheMaxSize() {
        return cacheMaxSize;
    }


    /**
     * Set the maximum size of the cache in KB.
     */
    public void setCacheMaxSize(int cacheMaxSize) {
        this.cacheMaxSize = cacheMaxSize;
    }


    // --------------------------------------------------------- Public Methods


    /**
     * Allocate resources for this directory context.
     */
    public void allocate() {
        ; // No action taken by the default implementation
    }


    /**
     * Release any resources allocated for this directory context.
     */
    public void release() {
        ; // No action taken by the default implementation
    }


    // -------------------------------------------------------- Context Methods


    /**
     * Retrieves the named object. If name is empty, returns a new instance 
     * of this context (which represents the same naming context as this 
     * context, but its environment may be modified independently and it may 
     * be accessed concurrently).
     * 
     * @param name the name of the object to look up
     * @return the object bound to name
     * @exception NamingException if a naming exception is encountered
     */
    public Object lookup(Name name)
        throws NamingException {
        return lookup(name.toString());
    }


    /**
     * Retrieves the named object.
     * 
     * @param name the name of the object to look up
     * @return the object bound to name
     * @exception NamingException if a naming exception is encountered
     */
    public abstract Object lookup(String name)
        throws NamingException;


    /**
     * Binds a name to an object. All intermediate contexts and the target 
     * context (that named by all but terminal atomic component of the name) 
     * must already exist.
     * 
     * @param name the name to bind; may not be empty
     * @param obj the object to bind; possibly null
     * @exception NameAlreadyBoundException if name is already bound
     * @exception InvalidAttributesException if object did not supply all 
     * mandatory attributes
     * @exception NamingException if a naming exception is encountered
     */
    public void bind(Name name, Object obj)
        throws NamingException {
        bind(name.toString(), obj);
    }


    /**
     * Binds a name to an object.
     * 
     * @param name the name to bind; may not be empty
     * @param obj the object to bind; possibly null
     * @exception NameAlreadyBoundException if name is already bound
     * @exception InvalidAttributesException if object did not supply all 
     * mandatory attributes
     * @exception NamingException if a naming exception is encountered
     */
    public void bind(String name, Object obj)
        throws NamingException {
        bind(name, obj, null);
    }


    /**
     * Binds a name to an object, overwriting any existing binding. All 
     * intermediate contexts and the target context (that named by all but 
     * terminal atomic component of the name) must already exist.
     * <p>
     * If the object is a DirContext, any existing attributes associated with 
     * the name are replaced with those of the object. Otherwise, any 
     * existing attributes associated with the name remain unchanged.
     * 
     * @param name the name to bind; may not be empty
     * @param obj the object to bind; possibly null
     * @exception InvalidAttributesException if object did not supply all 
     * mandatory attributes
     * @exception NamingException if a naming exception is encountered
     */
    public void rebind(Name name, Object obj)
        throws NamingException {
        rebind(name.toString(), obj);
    }


    /**
     * Binds a name to an object, overwriting any existing binding.
     * 
     * @param name the name to bind; may not be empty
     * @param obj the object to bind; possibly null