Start line:  
End line:  

Snippet Preview

Snippet HTML Code

Stack Overflow Questions
  /*
   * 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.catalina.valves;
 
 
 import static org.jboss.web.CatalinaMessages.MESSAGES;
 
 
 
Implementation of a Valve that performs filtering based on comparing the appropriate request property (selected based on which subclass you choose to configure into your Container's pipeline) against a set of regular expressions configured for this Valve.

This valve is configured by setting the allow and/or deny properties to a comma-delimited list of regular expressions (in the syntax supported by the jakarta-regexp library) to which the appropriate request property will be compared. Evaluation proceeds as follows:

  • The subclass extracts the request property to be filtered, and calls the common process() method.
  • If there are any deny expressions configured, the property will be compared to each such expression. If a match is found, this request will be rejected with a "Forbidden" HTTP response.
  • If there are any allow expressions configured, the property will be compared to each such expression. If a match is found, this request will be allowed to pass through to the next Valve in the current pipeline.
  • If one or more deny expressions was specified but no allow expressions, allow this request to pass through (because none of the deny expressions matched it).
  • The request will be rejected with a "Forbidden" HTTP response.

This Valve may be attached to any Container, depending on the granularity of the filtering you wish to perform.

Author(s):
Craig R. McClanahan
Version:
$Revision: 515 $ $Date: 2008-03-17 22:02:23 +0100 (Mon, 17 Mar 2008) $
 
 
 public abstract class RequestFilterValve
     extends ValveBase {
 
 
     // ----------------------------------------------------- Class Variables
 

    
The descriptive information related to this implementation.
 
     private static final String info =
         "org.apache.catalina.valves.RequestFilterValve/1.0";
 
 
     // ----------------------------------------------------- Instance Variables
 

    
The comma-delimited set of allow expressions.
 
     protected String allow = null;


    
The set of allow regular expressions we will evaluate.
 
     protected Pattern allows[] = new Pattern[0];


    
The set of deny regular expressions we will evaluate.
    protected Pattern denies[] = new Pattern[0];


    
The comma-delimited set of deny expressions.
    protected String deny = null;
    // ------------------------------------------------------------- Properties


    
Return a comma-delimited set of the allow expressions configured for this Valve, if any; otherwise, return null.
    public String getAllow() {
        return (this.);
    }


    
Set the comma-delimited set of the allow expressions configured for this Valve, if any.

Parameters:
allow The new set of allow expressions
    public void setAllow(String allow) {
        this. = allow;
         = precalculate(allow);
    }


    
Return a comma-delimited set of the deny expressions configured for this Valve, if any; otherwise, return null.
    public String getDeny() {
        return (this.);
    }


    
Set the comma-delimited set of the deny expressions configured for this Valve, if any.

Parameters:
deny The new set of deny expressions
    public void setDeny(String deny) {
        this. = deny;
         = precalculate(deny);
    }


    
Return descriptive information about this Valve implementation.
    public String getInfo() {
        return ();
    }
    // --------------------------------------------------------- Public Methods


    
Extract the desired request property, and pass it (along with the specified request and response objects) to the protected process() method to perform the actual filtering. This method must be implemented by a concrete subclass.

Parameters:
request The servlet request to be processed
response The servlet response to be created
Throws:
java.io.IOException if an input/output error occurs
javax.servlet.ServletException if a servlet error occurs
    public abstract void invoke(Request requestResponse response)
        throws IOExceptionServletException;
    // ------------------------------------------------------ Protected Methods


    
Return an array of regular expression objects initialized from the specified argument, which must be null or a comma-delimited list of regular expression patterns.

Parameters:
list The comma-separated list of patterns
Throws:
java.lang.IllegalArgumentException if one of the patterns has invalid syntax
    protected Pattern[] precalculate(String list) {
        if (list == null)
            return (new Pattern[0]);
        list = list.trim();
        if (list.length() < 1)
            return (new Pattern[0]);
        list += ",";
        ArrayList reList = new ArrayList();
        while (list.length() > 0) {
            int comma = list.indexOf(',');
            if (comma < 0)
                break;
            String pattern = list.substring(0, comma).trim();
            try {
                reList.add(Pattern.compile(pattern));
            } catch (PatternSyntaxException e) {
                IllegalArgumentException iae = new IllegalArgumentException
                    (.requestFilterValvePatternError(pattern));
                iae.initCause(e);
                throw iae;
            }
            list = list.substring(comma + 1);
        }
        Pattern reArray[] = new Pattern[reList.size()];
        return ((Pattern[]) reList.toArray(reArray));
    }


    
Perform the filtering that has been configured for this Valve, matching against the specified request property.

Parameters:
property The request property on which to filter
request The servlet request to be processed
response The servlet response to be processed
Throws:
java.io.IOException if an input/output error occurs
javax.servlet.ServletException if a servlet error occurs
    protected void process(String property,
                           Request requestResponse response)
        throws IOExceptionServletException {
        // Check the deny patterns, if any
        for (int i = 0; i < .i++) {
            if ([i].matcher(property).matches()) {
                response.sendError(.);
                return;
            }
        }
        // Check the allow patterns, if any
        for (int i = 0; i < .i++) {
            if ([i].matcher(property).matches()) {
                getNext().invoke(requestresponse);
                return;
            }
        }
        // Allow if denies specified but not allows
        if ((. > 0) && (. == 0)) {
            getNext().invoke(requestresponse);
            return;
        }
        // Deny this request
        response.sendError(.);
    }
New to GrepCode? Check out our FAQ X