Tomcat example source code file (DirContextURLConnection.java)

This example Tomcat source code file (DirContextURLConnection.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 - Tomcat tags/keywords

date, dircontext, filenotfoundexception, filenotfoundexception, io, ioexception, ioexception, naming, namingexception, net, network, object, object, proxydircontext, resource, security, string, string, util, vector

The Tomcat DirContextURLConnection.java source code

/*
 * 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.net.URL;
import java.net.URLConnection;
import java.io.IOException;
import java.io.InputStream;
import java.io.FileNotFoundException;
import java.security.Permission;
import java.util.Date;
import java.util.Enumeration;
import java.util.Vector;
import javax.naming.NamingException;
import javax.naming.NamingEnumeration;
import javax.naming.NameClassPair;
import javax.naming.directory.DirContext;
import javax.naming.directory.Attribute;
import javax.naming.directory.Attributes;
import org.apache.naming.JndiPermission;
import org.apache.naming.resources.Resource;
import org.apache.naming.resources.ResourceAttributes;

/**
 * Connection to a JNDI directory context.
 * <p/>
 * Note: All the object attribute names are the WebDAV names, not the HTTP 
 * names, so this class overrides some methods from URLConnection to do the
 * queries using the right names. Content handler is also not used; the 
 * content is directly returned.
 * 
 * @author <a href="mailto:remm@apache.org">Remy Maucherat
 * @version $Revision: 505593 $
 */
public class DirContextURLConnection 
    extends URLConnection {
    
    
    // ----------------------------------------------------------- Constructors
    
    
    public DirContextURLConnection(DirContext context, URL url) {
        super(url);
        if (context == null)
            throw new IllegalArgumentException
                ("Directory context can't be null");
        if (org.apache.naming.Constants.IS_SECURITY_ENABLED) {
            this.permission = new JndiPermission(url.toString());
	}
        this.context = context;
    }
    
    
    // ----------------------------------------------------- Instance Variables
    
    
    /**
     * Directory context.
     */
    protected DirContext context;
    
    
    /**
     * Associated resource.
     */
    protected Resource resource;
    
    
    /**
     * Associated DirContext.
     */
    protected DirContext collection;
    
    
    /**
     * Other unknown object.
     */
    protected Object object;
    
    
    /**
     * Attributes.
     */
    protected Attributes attributes;
    
    
    /**
     * Date.
     */
    protected long date;
    
    
    /**
     * Permission
     */
    protected Permission permission;


    // ------------------------------------------------------------- Properties
    
    
    /**
     * Connect to the DirContext, and retrive the bound object, as well as
     * its attributes. If no object is bound with the name specified in the
     * URL, then an IOException is thrown.
     * 
     * @throws IOException Object not found
     */
    public void connect()
        throws IOException {
        
        if (!connected) {
            
            try {
                date = System.currentTimeMillis();
                String path = getURL().getFile();
                if (context instanceof ProxyDirContext) {
                    ProxyDirContext proxyDirContext = 
                        (ProxyDirContext) context;
                    String hostName = proxyDirContext.getHostName();
                    String contextName = proxyDirContext.getContextName();
                    if (hostName != null) {
                        if (!path.startsWith("/" + hostName + "/"))
                            return;
                        path = path.substring(hostName.length()+ 1);
                    }
                    if (contextName != null) {
                        if (!path.startsWith(contextName + "/")) {
                            return;
                        } else {
                            path = path.substring(contextName.length());
                        }
                    }
                }
                object = context.lookup(path);
                attributes = context.getAttributes(path);
                if (object instanceof Resource)
                    resource = (Resource) object;
                if (object instanceof DirContext)
                    collection = (DirContext) object;
            } catch (NamingException e) {
                // Object not found
            }
            
            connected = true;
            
        }
        
    }
    
    
    /**
     * Return the content length value.
     */
    public int getContentLength() {
        return getHeaderFieldInt(ResourceAttributes.CONTENT_LENGTH, -1);
    }
    
    
    /**
     * Return the content type value.
     */
    public String getContentType() {
        return getHeaderField(ResourceAttributes.CONTENT_TYPE);
    }
    
    
    /**
     * Return the last modified date.
     */
    public long getDate() {
        return date;
    }
    
    
    /**
     * Return the last modified date.
     */
    public long getLastModified() {

        if (!connected) {
            // Try to connect (silently)
            try {
                connect();
            } catch (IOException e) {
            }
        }

        if (attributes == null)
            return 0;

        Attribute lastModified = 
            attributes.get(ResourceAttributes.LAST_MODIFIED);
        if (lastModified != null) {
            try {
                Date lmDate = (Date) lastModified.get();
                return lmDate.getTime();
            } catch (Exception e) {
            }
        }

        return 0;
    }
    
    
    /**
     * Returns the name of the specified header field.
     */
    public String getHeaderField(String name) {

        if (!connected) {
            // Try to connect (silently)
            try {
                connect();
            } catch (IOException e) {
            }
        }
        
        if (attributes == null)
            return (null);

        Attribute attribute = attributes.get(name);
        try {
            return attribute.get().toString();
        } catch (Exception e) {
            // Shouldn't happen, unless the attribute has no value
        }

        return (null);
        
    }
    
    
    /**
     * Get object content.
     */
    public Object getContent()
        throws IOException {
        
        if (!connected)
            connect();
        
        if (resource != null)
            return getInputStream();
        if (collection != null)
            return collection;
        if (object != null)
            return object;
        
        throw new FileNotFoundException();
        
    }
    
    
    /**
     * Get object content.
     */
    public Object getContent(Class[] classes)
        throws IOException {
        
        Object object = getContent();
        
        for (int i = 0; i < classes.length; i++) {
            if (classes[i].isInstance(object))
                return object;
        }
        
        return null;
        
    }
    
    
    /**
     * Get input stream.
     */
    public InputStream getInputStream() 
        throws IOException {
        
        if (!connected)
            connect();
        
        if (resource == null) {
            throw new FileNotFoundException();
        } else {
            // Reopen resource
            try {
                resource = (Resource) context.lookup(getURL().getFile());
            } catch (NamingException e) {
            }
        }
        
        return (resource.streamContent());
        
    }
    
    
    /**
     * Get the Permission for this URL
     */
    public Permission getPermission() {

        return permission;
    }


    // --------------------------------------------------------- Public Methods
    
    
    /**
     * List children of this collection. The names given are relative to this
     * URI's path. The full uri of the children is then : path + "/" + name.
     */
    public Enumeration list()
        throws IOException {
        
        if (!connected) {
            connect();
        }
        
        if ((resource == null) && (collection == null)) {
            throw new FileNotFoundException();
        }
        
        Vector result = new Vector();
        
        if (collection != null) {
            try {
                NamingEnumeration enumeration = context.list(getURL().getFile());
                while (enumeration.hasMoreElements()) {
                    NameClassPair ncp = (NameClassPair) enumeration.nextElement();
                    result.addElement(ncp.getName());
                }
            } catch (NamingException e) {
                // Unexpected exception
                throw new FileNotFoundException();
            }
        }
        
        return result.elements();
        
    }
    
    
}