httpframe.java

很棒的web服务器源代码

// HTTPFrame.java
// $Id: HTTPFrame.java,v 1.110 2004/01/06 10:07:51 ylafon Exp $
// (c) COPYRIGHT MIT and INRIA, 1997.
// Please first read the full copyright statement in file COPYRIGHT.html

package org.w3c.jigsaw.frames;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;

import org.w3c.tools.codec.Base64Encoder;
import org.w3c.tools.sorter.Sorter;
import org.w3c.tools.resources.Attribute;
import org.w3c.tools.resources.AttributeRegistry;
import org.w3c.tools.resources.BooleanAttribute;
import org.w3c.tools.resources.IntegerAttribute;
import org.w3c.tools.resources.LongAttribute;
import org.w3c.tools.resources.DoubleAttribute;
import org.w3c.tools.resources.StringAttribute;
import org.w3c.tools.resources.StringArrayAttribute;
import org.w3c.tools.resources.ProtocolFrame;
import org.w3c.tools.resources.ProtocolFrame;
import org.w3c.tools.resources.LookupState;
import org.w3c.tools.resources.LookupResult;
import org.w3c.tools.resources.ResourceReference;
import org.w3c.tools.resources.InvalidResourceException;
import org.w3c.tools.resources.MultipleLockException;
import org.w3c.tools.resources.Resource;
import org.w3c.tools.resources.FramedResource;
import org.w3c.tools.resources.ContainerInterface;
import org.w3c.tools.resources.ContainerResource;
import org.w3c.tools.resources.DirectoryResource;
import org.w3c.tools.resources.FileResource;
import org.w3c.tools.resources.RequestInterface;
import org.w3c.tools.resources.ReplyInterface;
import org.w3c.tools.resources.event.AttributeChangedEvent;
import org.w3c.jigsaw.http.Client;
import org.w3c.jigsaw.http.ClientException;
import org.w3c.jigsaw.http.httpd;
import org.w3c.jigsaw.http.Request;
import org.w3c.jigsaw.http.Reply;
import org.w3c.jigsaw.http.HTTPException;

import org.w3c.jigsaw.html.HtmlGenerator;
import org.w3c.jigsaw.html.HtmlLink;
import org.w3c.www.mime.MimeType;
import org.w3c.www.http.ByteRangeOutputStream;
import org.w3c.www.http.HTTP;
import org.w3c.www.http.HttpContentRange;
import org.w3c.www.http.HttpDate;
import org.w3c.www.http.HttpEntityTag;
import org.w3c.www.http.HttpFactory;
import org.w3c.www.http.HttpInteger;
import org.w3c.www.http.HttpMimeType;
import org.w3c.www.http.HttpRange;
import org.w3c.www.http.HttpString;
import org.w3c.www.http.HttpTokenList;

import org.w3c.tools.crypt.Md5;

import org.w3c.tools.resources.ProtocolException;
import org.w3c.tools.resources.ResourceException;

/**
 * Default class to handle the HTTP protocol, manage FileResource and
 * DirectoryResource.
 */
public class HTTPFrame extends ProtocolFrame {

    public static final 
    String STATE_CONTENT_LOCATION = "org.w3c.jigsaw.frames.HTTPFrame.cl";

    private static final boolean debug = false;

    /**
     * Condition check return code - Condition existed but failed.
     */
    public static final int COND_FAILED = 1;
    /**
     * Condition check return code - Condition existed and succeeded.
     */
    public static final int COND_OK = 2;
    /**
     * Condition check return code - Condition existed and succeeded 
     *                               but is a weak validation.
     */
    public static final int COND_WEAK = 3;    

    private   static HttpTokenList _accept_ranges  = null;
    static {
	String accept_ranges[] = { "bytes" };
	_accept_ranges = HttpFactory.makeStringList(accept_ranges);
    }
    /**
     * Methods allowed by instances of that class in particular:
     */
    protected        HttpTokenList  allowed = null;

    /**
     * Attributes index - The index for the quality attribute.
     */
    protected static int ATTR_QUALITY = -1 ;
    /**
     * Attribute index - The index for the title attribute.
     */
    protected static int ATTR_TITLE = -1 ;
    /**
     * Attribute index - The index for the content languages attribute.
     */
    protected static int ATTR_CONTENT_LANGUAGE = -1 ;
    /**
     * Attribute index - The index for the content encodings attribute.
     */
    protected static int ATTR_CONTENT_ENCODING = -1 ;
    /**
     * Attribute index - The index for the content type attribute.
     */
    protected static int ATTR_CONTENT_TYPE = -1 ;
    /**
     * Attribute index - The index for the charset attribute.
     */
    protected static int ATTR_CHARSET = -1 ;
    /**
     * Attribute index - The index for the content length attribute.
     */
    protected static int ATTR_CONTENT_LENGTH = -1 ;
    /**
     * Attribute index - The icon (if any) associated to the resource.
     */
    protected static int ATTR_ICON = -1 ;
    /**
     * Attribute index - Max age: the maximum drift allowed from reality.
     */
    protected static int ATTR_MAXAGE = -1 ;
    /**
     * Attribute index - Send MD5 Digest: the md5 digest of the resource sent
     */
    protected static int ATTR_MD5 = -1;
    /**
     * Attribute index - delete allowed for the associated resource ?
     */
    protected static int ATTR_ALLOW_DEL = -1;

    //
    // Attribute relative to FileResource
    //

    /**
     * Attribute index - Do we allow PUT method on this file.
     */
    protected static int ATTR_PUTABLE = -1 ;

    //
    // Attribute relative to DirectoryResource
    //

    /**
     * Attribute index - The index for our relocate attribute.
     */
    protected static int ATTR_RELOCATE = -1 ;
    /**
     * Attribute index - our index resource name.
     */
    protected static int ATTR_INDEX = -1 ;
    /**
     * Attribute index - our indexes resource name.
     */
    protected static int ATTR_INDEXES = -1 ;
    /**
     * Attribute index - The icon directory to use in dir listing.
     */
    protected static int ATTR_ICONDIR = -1 ;
    /**
     * Attribute index - Allow the GNN browse method.
     */
    protected static int ATTR_BROWSABLE = -1 ;
    /**
     * Attribute index - Style sheet for directory listing
     */
    protected static int ATTR_STYLE_LINK = -1 ;

    static {
	Attribute a   = null ;
	Class     cls = null ;

	// Get a pointer to our class:
	try {
	    cls = Class.forName("org.w3c.jigsaw.frames.HTTPFrame") ;
	} catch (Exception ex) {
	    ex.printStackTrace() ;
	    System.exit(1) ;
	}
	// The quality attribute:
	a = new DoubleAttribute("quality"
				, new Double(1.0) 
				, Attribute.EDITABLE);
	ATTR_QUALITY = AttributeRegistry.registerAttribute(cls, a) ;
	// The title attribute:
	a = new StringAttribute("title"
				, null
				, Attribute.EDITABLE) ;
	ATTR_TITLE = AttributeRegistry.registerAttribute(cls, a) ;
	// The content language attribute:
	a = new LanguageAttribute("content-language"
				  , null
				  , Attribute.EDITABLE) ;
	ATTR_CONTENT_LANGUAGE = AttributeRegistry.registerAttribute(cls,a);
	// The content encoding attribute:
	a = new EncodingAttribute("content-encoding"
				  , null
				  , Attribute.EDITABLE) ;
	ATTR_CONTENT_ENCODING = AttributeRegistry.registerAttribute(cls,a);
	// The content type attribute:
	a = new MimeTypeAttribute("content-type"
				  , null
				  , Attribute.EDITABLE) ;
	ATTR_CONTENT_TYPE = AttributeRegistry.registerAttribute(cls,a);
	// The Charset attribute:
	a = new StringAttribute("charset"
				, null
				, Attribute.EDITABLE) ;
	ATTR_CHARSET = AttributeRegistry.registerAttribute(cls,a);
        // The content length attribute:
	a = new IntegerAttribute("content-length"
				 , null
				 , Attribute.COMPUTED);
	ATTR_CONTENT_LENGTH = AttributeRegistry.registerAttribute(cls,a);
	// The icon attribute:
	a = new StringAttribute("icon"
				, null
				, Attribute.EDITABLE) ;
	ATTR_ICON = AttributeRegistry.registerAttribute(cls, a) ;
	// The max age attribute (in ms)
	a = new LongAttribute("maxage"
			      , null
			      , Attribute.EDITABLE) ;
	ATTR_MAXAGE = AttributeRegistry.registerAttribute(cls, a) ;
	// Should we send MD5 digest?
	a = new BooleanAttribute("send-md5"
				 , Boolean.FALSE
				 , Attribute.EDITABLE);
	ATTR_MD5 = AttributeRegistry.registerAttribute(cls, a) ;
	// delete allowed for the associated resource ?
	a = new BooleanAttribute("allow-delete"
				 , Boolean.FALSE
				 , Attribute.EDITABLE);
	ATTR_ALLOW_DEL = AttributeRegistry.registerAttribute(cls, a) ;

	//
	// Attribute relative to a FileResource
	//

	// The putable flag:
	a = new BooleanAttribute("putable"
				 , Boolean.FALSE
				 , Attribute.EDITABLE) ;
	ATTR_PUTABLE = AttributeRegistry.registerAttribute(cls, a) ;

	//
	// Attribute relative to a DirectoryResource
	//

	//Should we relocate invalid request to this directory ?
	a = new BooleanAttribute("relocate"
				 , Boolean.TRUE
				 , Attribute.EDITABLE);
	ATTR_RELOCATE = AttributeRegistry.registerAttribute(cls, a) ;
	// Our index resource name (optional).
	a = new StringAttribute("index"
				, null
				, Attribute.EDITABLE) ;
	ATTR_INDEX = AttributeRegistry.registerAttribute(cls, a) ;
	// Our indexes resource name 
	a = new StringArrayAttribute("indexes"
				     , null
				     , Attribute.EDITABLE) ;
	ATTR_INDEXES = AttributeRegistry.registerAttribute(cls, a) ;
	// Our icon directory.
	a = new StringAttribute("icondir"
				, null
				, Attribute.EDITABLE) ;
	ATTR_ICONDIR = AttributeRegistry.registerAttribute(cls,a);
	// The browsable flag:
	a = new BooleanAttribute("browsable"
				 , Boolean.FALSE
				 , Attribute.EDITABLE) ;
	ATTR_BROWSABLE = AttributeRegistry.registerAttribute(cls, a) ;
	// The style sheet attribute:
	a = new StringAttribute("style-sheet-link"
				, null
				, Attribute.EDITABLE) ;
	ATTR_STYLE_LINK = AttributeRegistry.registerAttribute(cls, a) ;
    }

    /**
     * The associated DirectoryResource (if any)
     */
    protected DirectoryResource dresource  = null;

    /**
     * The associated FileResource (if any)
     */
    protected FileResource      fresource  = null;

    /**
     * Register this frame to the given resource.
     * @param resource The resource associated with this frame.
     */
    public void registerResource(FramedResource resource) {
	super.registerResource(resource);
	if (resource instanceof FileResource)
	    fresource = (FileResource) resource;
	else if (resource instanceof DirectoryResource)
	    dresource = (DirectoryResource) resource;
    }

    /**
     * Get the associated FileResource (if any)
     * @return a FileResource instance or <strong>null</strong>
     * if no FileResource is associated with this frame.
     */
    public FileResource getFileResource() {
	return fresource;
    }

    /**
     * Get the associated DirectoryResource (if any)
     * @return a DirectoryResource instance or <strong>null</strong>
     * if no DirectoryResource is associated with this frame.
     */
    public DirectoryResource getDirectoryResource() {
	return dresource;
    }

    /**
     * use this one instead of registerResource if the resource type 
     * doesn't matter or if this is not a file or a directory resource.
     * In subclasses you should have to do that:
     * <pre>
     *  public void registerResource(FramedResource resource) {
     *   super.registerOtherResource(resource);
     *  }
     * </pre>
     * @param the resource to register.
     */
    public void registerOtherResource(FramedResource resource) {
	super.registerResource(resource);
	dresource = null;
	fresource = null;
    }

    // The HTTPResource keeps a cache of ready to use Http values. This 
    // allows to save converting to/from wire rep these objects. Not 
    // much CPU time, but also memory is spared.
    HttpMimeType  contenttype     = null;
    HttpInteger   contentlength   = null;
    HttpDate      lastmodified    = null;
    HttpTokenList contentencoding = null;
    HttpTokenList contentlanguage = null;

    // The Http entity tag for this resource (for FileResource only)
    HttpEntityTag etag   = null;
    // the MD5 digest for this resource (for FileResource only)
    HttpString md5Digest = null;

    /**
     * Get this resource's help url.
     * @return An URL, encoded as a String, or <strong>null</strong> if not
     * available.
     */

    public String getHelpURL() {
	httpd server = (httpd) getServer();
	if ( server == null ) 
	    return null;
	String docurl = server.getDocumentationURL();
	if ( docurl == null )
	    return null;
	return docurl + "/" + getClass().getName() + ".html";
    }

    /**
     * Get the help URL for that resource's attribute.
     * @param topic The topic (can be an attribute name, or a property, etc).
     * @return A String encoded URL, or <strong>null</strong>.
     */

    public String getHelpURL(String topic) {
	httpd server = (httpd) getServer();
	if ( server == null ) 
	    return null;
	String docurl = server.getDocumentationURL();
	if ( docurl == null )
	    return null;
	Class defines = AttributeRegistry.getAttributeClass(getClass(), topic);
	if ( defines != null ) 
	    return docurl + "/" + defines.getName() + ".html";
	return null;
    }

    /** 
     * give the md5 digest from cache or calculate it
     * @return the HttpString version of the digest
     */

    private HttpString getMd5Digest() {
	if (md5Digest != null)
	    return md5Digest;
	// not found, compute it if necessary!
	Resource r = getResource();
	if (r instanceof FileResource) {
	    try {
		Md5 md5 = new Md5 (
		    new FileInputStream(((FileResource)r).getFile()));
		String s = null;
		try {
		    byte b[] = md5.getDigest();
		    Base64Encoder b64;