com.ocpsoft.rewrite.servlet.config.Header Maven / Gradle / Ivy

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/*
* Copyright 2011 Lincoln Baxter, III
 * 
 * Licensed 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 com.ocpsoft.rewrite.servlet.config;

import java.util.Collections;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import com.ocpsoft.common.util.Assert;
import com.ocpsoft.rewrite.bind.Bindings;
import com.ocpsoft.rewrite.bind.ParameterizedPattern;
import com.ocpsoft.rewrite.bind.RegexParameter;
import com.ocpsoft.rewrite.context.EvaluationContext;
import com.ocpsoft.rewrite.event.Rewrite;
import com.ocpsoft.rewrite.servlet.http.event.HttpServletRewrite;

/**
 * Responsible for asserting on {@link HttpServletRequest#getHeader(String)} values.
 * 
 * @author Lincoln Baxter, III
 */
public class Header extends HttpCondition
{
   private final ParameterizedPattern name;
   private final ParameterizedPattern value;

   private Header(final String name, final String value)
   {
      Assert.notNull(name, "Header name pattern cannot be null.");
      Assert.notNull(value, "Header value pattern cannot be null.");
      this.name = new ParameterizedPattern(name);
      this.value = new ParameterizedPattern(value);
   }

   /**
    * Return a {@link Header} condition that matches against both header name and values.
    * 
    * See also: {@link HttpServletRequest#getHeader(String)}
    * 
    * @param name Regular expression matching the header name
    * @param value Regular expression matching the header value
    */
   public static Header matches(final String name, final String value)
   {
      return new Header(name, value);
   }

   /**
    * Return a {@link Header} condition that matches only against the existence of a header with a name matching the
    * given pattern. The header value is ignored.
    * 
    * See also: {@link HttpServletRequest#getHeader(String)}
    * 
    * @param name Regular expression matching the header name
    */
   public static Header exists(final String name)
   {
      return new Header(name, ".*");
   }

   /**
    * Return a {@link Header} condition that matches only against the existence of a header with value matching the
    * given pattern. The header name is ignored.
    * 
    * @param value Regular expression matching the header value
    */
   public static Header valueExists(final String value)
   {
      return new Header(".*", value);
   }

   @Override
   public boolean evaluateHttp(final HttpServletRewrite event, final EvaluationContext context)
   {
      HttpServletRequest request = event.getRequest();
      for (String header : Collections.list(request.getHeaderNames()))
      {
         if (name.matches(event, context, header) && matchesValue(event, context, request, header))
         {
            Map parameters = name.parse(event, context, header);
            parameters = value.parse(event, context, header);

            if (Bindings.enqueuePreOperationSubmissions(event, context, parameters)
                     && Bindings.enqueuePreOperationSubmissions(event, context, parameters))
            {
               return true;
            }
         }
      }
      return false;
   }

   private boolean matchesValue(Rewrite event, EvaluationContext context, final HttpServletRequest request,
            final String header)
   {
      for (String contents : Collections.list(request.getHeaders(header)))
      {
         if (value.matches(event, context, contents))
         {
            return true;
         }
      }
      return false;
   }
}