org.ocpsoft.rewrite.servlet.config.Header Maven / Gradle / Ivy
/*
* 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 org.ocpsoft.rewrite.servlet.config;
import java.util.Collections;
import java.util.Enumeration;
import java.util.LinkedHashSet;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import org.ocpsoft.common.util.Assert;
import org.ocpsoft.rewrite.config.Condition;
import org.ocpsoft.rewrite.config.ConfigurationRuleParameterBuilder;
import org.ocpsoft.rewrite.context.EvaluationContext;
import org.ocpsoft.rewrite.event.Rewrite;
import org.ocpsoft.rewrite.param.ParameterStore;
import org.ocpsoft.rewrite.param.Parameterized;
import org.ocpsoft.rewrite.param.ParameterizedPattern;
import org.ocpsoft.rewrite.param.ParameterizedPatternParser;
import org.ocpsoft.rewrite.param.RegexParameterizedPatternParser;
import org.ocpsoft.rewrite.servlet.http.event.HttpServletRewrite;
/**
* A {@link Condition} responsible for asserting on specified values of {@link HttpServletRequest#getHeader(String)}.
*
* @author Lincoln Baxter, III
*/
public abstract class Header extends HttpCondition implements Parameterized
{
private final ParameterizedPatternParser name;
private final ParameterizedPatternParser 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 RegexParameterizedPatternParser(name);
this.value = new RegexParameterizedPatternParser(value);
}
/**
* Create a {@link Header} condition that matches against both header name and values.
*
* The given name and value patterns may be parameterized:
*
*
* Header.matches("Accept-Encoding", "{encoding}")
* Header.matches("Accept-{type}", "{value}")
* ...
*
*
*
* @see {@link ConfigurationRuleParameterBuilder#where(String) {@link HttpServletRequest#getHeader(String)}
*
* @param name {@link ParameterizedPattern} matching the header name.
* @param value {@link ParameterizedPattern} matching the header value.
*/
public static Header matches(final String name, final String value)
{
return new Header(name, value) {
@Override
public String toString()
{
return "Header.matches(\"" + name + "\", \"" + value + "\")";
}
};
}
/**
* Create 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.
*
* The given name pattern may be parameterized:
*
*
* Header.exists("Accept-Encoding")
* Header.exists("Accept-{acceptType}")
* Header.exists("{anything}")
* ...
*
*
*
* @see {@link ConfigurationRuleParameterBuilder#where(String) {@link HttpServletRequest#getHeader(String)}
*
* @param name {@link ParameterizedPattern} matching the header name.
*/
public static Header exists(final String name)
{
return new Header(name, "{" + Header.class.getName() + "_value}") {
@Override
public String toString()
{
return "Header.exists(\"" + name + "\")";
}
};
}
/**
* Create a {@link Header} condition that matches only against the existence of a header with value matching the
* given pattern. The header name is ignored.
*
* The given value pattern may be parameterized:
*
*
* Header.valueExists("application/xml")
* Header.valueExists("application/{type}")
* Header.valueExists("{anything}")
* ...
*
*
*
* @see {@link ConfigurationRuleParameterBuilder#where(String) {@link HttpServletRequest#getHeader(String)}
*
* @param value {@link ParameterizedPattern} matching the header value.
*/
public static Header valueExists(final String value)
{
return new Header("{" + Header.class.getName() + "_name}", value) {
@Override
public String toString()
{
return "Header.valueExists(\"" + value + "\")";
}
};
}
@Override
@SuppressWarnings("unchecked")
public boolean evaluateHttp(final HttpServletRewrite event, final EvaluationContext context)
{
HttpServletRequest request = event.getRequest();
Enumeration headerNames = request.getHeaderNames();
if (headerNames != null)
{
for (String header : Collections.list(headerNames))
{
if (name.parse(header).submit(event, context) && matchesValue(event, context, request, header))
{
return true;
}
}
}
return false;
}
@SuppressWarnings("unchecked")
private boolean matchesValue(Rewrite event, EvaluationContext context, final HttpServletRequest request,
final String header)
{
Enumeration headers = request.getHeaders(header);
if (headers != null)
{
for (String contents : Collections.list(headers))
{
if (value.parse(contents).submit(event, context))
{
return true;
}
}
}
return false;
}
@Override
public Set getRequiredParameterNames()
{
Set result = new LinkedHashSet();
result.addAll(name.getRequiredParameterNames());
result.addAll(value.getRequiredParameterNames());
return result;
}
@Override
public void setParameterStore(ParameterStore store)
{
name.setParameterStore(store);
value.setParameterStore(store);
}
}