proxydircontext.java

Tomcat 4.1与WebServer集成组件的源代码包.

     * @return a non-null enumeration of SearchResult objects. Each 
     * SearchResult contains the attributes identified by attributesToReturn 
     * and the name of the corresponding object, named relative to the 
     * context named by name.
     * @exception NamingException if a naming exception is encountered
     */
    public NamingEnumeration search(Name name, Attributes matchingAttributes)
        throws NamingException {
        return dirContext.search(parseName(name), matchingAttributes);
    }


    /**
     * Searches in a single context for objects that contain a specified set 
     * of attributes.
     * 
     * @param name the name of the context to search
     * @param matchingAttributes the attributes to search for. If empty or 
     * null, all objects in the target context are returned.
     * @return a non-null enumeration of SearchResult objects. Each 
     * SearchResult contains the attributes identified by attributesToReturn 
     * and the name of the corresponding object, named relative to the 
     * context named by name.
     * @exception NamingException if a naming exception is encountered
     */
    public NamingEnumeration search(String name, Attributes matchingAttributes)
        throws NamingException {
        return dirContext.search(parseName(name), matchingAttributes);
    }


    /**
     * Searches in the named context or object for entries that satisfy the 
     * given search filter. Performs the search as specified by the search 
     * controls.
     * 
     * @param name the name of the context or object to search
     * @param filter the filter expression to use for the search; may not be 
     * null
     * @param cons the search controls that control the search. If null, 
     * the default search controls are used (equivalent to 
     * (new SearchControls())).
     * @return an enumeration of SearchResults of the objects that satisfy 
     * the filter; never null
     * @exception InvalidSearchFilterException if the search filter specified 
     * is not supported or understood by the underlying directory
     * @exception InvalidSearchControlsException if the search controls 
     * contain invalid settings
     * @exception NamingException if a naming exception is encountered
     */
    public NamingEnumeration search(Name name, String filter, 
                                    SearchControls cons)
        throws NamingException {
        return dirContext.search(parseName(name), filter, cons);
    }


    /**
     * Searches in the named context or object for entries that satisfy the 
     * given search filter. Performs the search as specified by the search 
     * controls.
     * 
     * @param name the name of the context or object to search
     * @param filter the filter expression to use for the search; may not be 
     * null
     * @param cons the search controls that control the search. If null, 
     * the default search controls are used (equivalent to 
     * (new SearchControls())).
     * @return an enumeration of SearchResults of the objects that satisfy 
     * the filter; never null
     * @exception InvalidSearchFilterException if the search filter 
     * specified is not supported or understood by the underlying directory
     * @exception InvalidSearchControlsException if the search controls 
     * contain invalid settings
     * @exception NamingException if a naming exception is encountered
     */
    public NamingEnumeration search(String name, String filter, 
                                    SearchControls cons)
        throws NamingException {
        return dirContext.search(parseName(name), filter, cons);
    }


    /**
     * Searches in the named context or object for entries that satisfy the 
     * given search filter. Performs the search as specified by the search 
     * controls.
     * 
     * @param name the name of the context or object to search
     * @param filterExpr the filter expression to use for the search. 
     * The expression may contain variables of the form "{i}" where i is a 
     * nonnegative integer. May not be null.
     * @param filterArgs the array of arguments to substitute for the 
     * variables in filterExpr. The value of filterArgs[i] will replace each 
     * occurrence of "{i}". If null, equivalent to an empty array.
     * @param cons the search controls that control the search. If null, the 
     * default search controls are used (equivalent to (new SearchControls())).
     * @return an enumeration of SearchResults of the objects that satisy the 
     * filter; never null
     * @exception ArrayIndexOutOfBoundsException if filterExpr contains {i} 
     * expressions where i is outside the bounds of the array filterArgs
     * @exception InvalidSearchControlsException if cons contains invalid 
     * settings
     * @exception InvalidSearchFilterException if filterExpr with filterArgs 
     * represents an invalid search filter
     * @exception NamingException if a naming exception is encountered
     */
    public NamingEnumeration search(Name name, String filterExpr,
                                    Object[] filterArgs, SearchControls cons)
        throws NamingException {
        return dirContext.search(parseName(name), filterExpr, filterArgs, 
                                 cons);
    }


    /**
     * Searches in the named context or object for entries that satisfy the 
     * given search filter. Performs the search as specified by the search 
     * controls.
     * 
     * @param name the name of the context or object to search
     * @param filterExpr the filter expression to use for the search. 
     * The expression may contain variables of the form "{i}" where i is a 
     * nonnegative integer. May not be null.
     * @param filterArgs the array of arguments to substitute for the 
     * variables in filterExpr. The value of filterArgs[i] will replace each 
     * occurrence of "{i}". If null, equivalent to an empty array.
     * @param cons the search controls that control the search. If null, the 
     * default search controls are used (equivalent to (new SearchControls())).
     * @return an enumeration of SearchResults of the objects that satisy the 
     * filter; never null
     * @exception ArrayIndexOutOfBoundsException if filterExpr contains {i} 
     * expressions where i is outside the bounds of the array filterArgs
     * @exception InvalidSearchControlsException if cons contains invalid 
     * settings
     * @exception InvalidSearchFilterException if filterExpr with filterArgs 
     * represents an invalid search filter
     * @exception NamingException if a naming exception is encountered
     */
    public NamingEnumeration search(String name, String filterExpr,
                                    Object[] filterArgs, SearchControls cons)
        throws NamingException {
        return dirContext.search(parseName(name), filterExpr, filterArgs, 
                                 cons);
    }


    // ------------------------------------------------------ Protected Methods


    /**
     * Parses a name.
     * 
     * @return the parsed name
     */
    protected String parseName(String name) 
        throws NamingException {
        return name;
    }


    /**
     * Parses a name.
     * 
     * @return the parsed name
     */
    protected Name parseName(Name name) 
        throws NamingException {
        return name;
    }


    /**
     * Lookup in cache.
     */
    protected CacheEntry cacheLookupAndLoad(String name) {
        if (cache == null)
            return (null);
        CacheEntry cacheEntry = (CacheEntry) cache.get(name);
        if (cacheEntry == null) {
            cacheEntry = new CacheEntry();
            cacheEntry.name = name;
            // Load entry
            if (!cacheLoad(cacheEntry))
                return null;
            return (cacheEntry);
        } else {
            if (!validate(cacheEntry)) {
                if (!revalidate(cacheEntry)) {
                    cacheUnload(cacheEntry.name);
                    return (null);
                } else {
                    cacheEntry.timestamp = 
                        System.currentTimeMillis() + cacheTTL;
                }
            }
            return (cacheEntry);
        }
    }


    /**
     * Validate entry.
     */
    protected boolean validate(CacheEntry entry) {
        if ((entry.resource != null) 
            //            && (entry.resource.getContent() != null) 
            && (System.currentTimeMillis() < entry.timestamp)) {
            return true;
        }
        return false;
    }


    /**
     * Revalidate entry.
     */
    protected boolean revalidate(CacheEntry entry) {
        // Get the attributes at the given path, and check the last 
        // modification date
        if (entry.attributes == null)
            return false;
        long lastModified = AttributeHelper.getLastModified(entry.attributes);
        //        long contentLength = entry.attributes.getContentLength();
        if (lastModified <= 0)
            return false;
        try {
//             Attributes tempAttributes = dirContext.getAttributes(entry.name);
             Attributes attributes = dirContext.getAttributes(entry.name);
//             ResourceAttributes attributes = null;
//             if (!(tempAttributes instanceof ResourceAttributes)) {
//                 attributes = new ResourceAttributes(tempAttributes);
//             } else {
//                 attributes = (ResourceAttributes) tempAttributes;
//             }
            long lastModified2 = AttributeHelper.getLastModified(attributes);
            //            long contentLength2 = attributes.getContentLength();
            return (lastModified == lastModified2) ;
                //  && (contentLength == contentLength2);
        } catch (NamingException e) {
            return false;
        }
    }


    /**
     * Load entry into cache.
     */
    protected boolean cacheLoad(CacheEntry entry) {

        if (cache == null)
            return false;

        String name = entry.name;

        // Retrieve missing info

        // Retrieving attributes
        if (entry.attributes == null) {
            try {
                Attributes attributes = dirContext.getAttributes(entry.name);
//                 if (!(attributes instanceof ResourceAttributes)) {
//                     entry.attributes = 
//                         new ResourceAttributes(attributes);
//                 } else {
//                     entry.attributes = (ResourceAttributes) attributes;
//                 }
            } catch (NamingException e) {
                return false;
            }
        }

        // Retriving object
        if ((entry.resource == null) && (entry.context == null)) {
            try {
                Object object = dirContext.lookup(name);
//                 if (object instanceof InputStream) {
//                     entry.resource = new Resource((InputStream) object);
//                 } else if (object instanceof DirContext) {
//                     entry.context = (DirContext) object;
//                 } else if (object instanceof Resource) {
//                     entry.resource = (Resource) object;
//                 } else {
//                     entry.resource = new Resource(new ByteArrayInputStream
//                         (object.toString().getBytes()));
//                 }
                entry.resource=object;
            } catch (NamingException e) {
                return false;
            }
        }

        // TODO: lazy loading. We may list a dir, there's no reason to load
        // all entries ( we may just look at attributes )
        
        // Load object content. We cache entries without content ( users, etc ) 
        /*
          if ((entry.resource != null) && (entry.resource.getContent() == null) 
            //            && (entry.attributes.getContentLength() >= 0)
            && (entry.attributes.getContentLength() < cacheObjectMaxSize)) {
            int length = (int) entry.attributes.getContentLength();
            InputStream is = null;
            try {
                is = entry.resource.streamContent();
                int pos = 0;
                byte[] b = new byte[length];
                while (pos < length) {
                    int n = is.read(b, pos, length - pos);
                    if (n < 0)
                        break;
                    pos = pos + n;
                }
                entry.resource.setContent(b);
            } catch (IOException e) {
                ; // Ignore
            } finally {
                try {
                    if (is != null)
                        is.close();
                } catch (IOException e) {
                    ; // Ignore
                }
            }
        }
        */
        // Set timestamp
        entry.timestamp = System.currentTimeMillis() + cacheTTL;

        // Add new entry to cache
        cache.put(name, entry);

        return true;

    }


    /**
     * Remove entry from cache.
     */
    protected boolean cacheUnload(String name) {
        if (cache == null)
            return false;
        return (cache.remove(name) != null);
    }

    // ------------------------------------------------- CacheEntry Inner Class


    protected class CacheEntry {


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


        long timestamp = -1;
        String name = null;
        Attributes attributes = null;
        //ResourceAttributes attributes = null;
        Object resource = null;
        DirContext context = null;


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


        public void recycle() {
            timestamp = -1;
            name = null;
            attributes = null;
            resource = null;
            context = null;
        }


        public String toString() {
            return ("Cache entry: " + name + "\n"
                    + "Attributes: " + attributes + "\n"
                    + "Resource: " + resource + "\n"
                    + "Context: " + context);
        }


    }


}