/*
* Copyright 2011 <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
*
* 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.Arrays;
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} that inspects values returned by {@link HttpServletRequest#getParameterMap()}
*
* @author <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
*/
public abstract class RequestParameter extends HttpCondition implements Parameterized
{
private final ParameterizedPatternParser name;
private final ParameterizedPatternParser value;
private RequestParameter(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 Condition} that matches against both request parameter names and values.
* <p>
* Parameter name and value expressions may be parameterized:
* <p>
* <code>
* RequestParameter.matches("username", "guest")<br/>
* RequestParameter.matches("username", "{name}")<br/>
* RequestParameter.matches("{anything}", "{value}")<br/>
* </code>
*
* @param name {@link ParameterizedPattern} matching the request parameter name.
* @param value {@link ParameterizedPattern} matching the request parameter value.
*
* @see ConfigurationRuleParameterBuilder#where(String) {@link HttpServletRequest#getParameterMap()}
*/
public static RequestParameter matches(final String name, final String value)
{
return new RequestParameter(name, value) {
@Override
public String toString()
{
return "RequestParameter.matches(\"" + name + "\", \"" + value + "\")";
}
};
}
public static RequestParameter matchesAll(final String name, final String value)
{
return new AllRequestParameters(name, value) {
@Override
public String toString()
{
return "RequestParameter.matchesAll(\"" + name + "\", \"" + value + "\")";
}
};
}
/**
* Create a {@link Condition} that matches against the existence of a request parameter with a name matching the
* given pattern. The parameter value is ignored.
* <p>
* Parameter name expressions may be parameterized:
* <p>
* <code>
* RequestParameter.exists("username")<br/>
* RequestParameter.exists("{name}")<br/>
* ...
* </code>
*
* @param name {@link ParameterizedPattern} matching the request parameter name.
*
* @see ConfigurationRuleParameterBuilder#where(String) {@link HttpServletRequest#getParameterMap()}
*/
public static RequestParameter exists(final String name)
{
return new RequestParameter(name, "{" + RequestParameter.class.getName() + "_" + name + "_value}") {
@Override
public String toString()
{
return "RequestParameter.exists(\"" + name + "\")";
}
};
}
/**
* Create a {@link Condition} that matches only against the existence of a request parameter value matching the given
* pattern. The parameter name is ignored.
* <p>
* Parameter value expressions may be parameterized:
* <p>
* <code>
* RequestParameter.valueExists("guest")<br/>
* RequestParameter.valueExists("{username}")<br/>
* ...
* </code>
*
* @param name {@link ParameterizedPattern} matching the request parameter name.
*
* @see ConfigurationRuleParameterBuilder#where(String) {@link HttpServletRequest#getParameterMap()}
*/
public static RequestParameter valueExists(final String value)
{
return new RequestParameter("{" + RequestParameter.class.getName() + "_" + value + "_name}", value) {
@Override
public String toString()
{
return "RequestParameter.valueExists(\"" + value + "\")";
}
};
}
@Override
public boolean evaluateHttp(final HttpServletRewrite event, final EvaluationContext context)
{
HttpServletRequest request = event.getRequest();
Enumeration<?> parameterNames = request.getParameterNames();
while (parameterNames.hasMoreElements())
{
String parameter = parameterNames.nextElement().toString();
if (name.parse(parameter).submit(event, context) && matchesValue(event, context, request, parameter))
{
return true;
}
}
return false;
}
private boolean matchesValue(Rewrite event, EvaluationContext context, final HttpServletRequest request,
final String parameterName)
{
for (String contents : Arrays.asList(request.getParameterValues(parameterName)))
{
if (value.parse(contents).submit(event, context))
{
return true;
}
}
return false;
}
/**
* Get the {@link ParameterizedPattern} of the request parameter name.
*/
public ParameterizedPatternParser getNameExpression()
{
return name;
}
/**
* Get the {@link ParameterizedPattern} of the request parameter value.
*/
public ParameterizedPatternParser getValueExpression()
{
return value;
}
private abstract static class AllRequestParameters extends RequestParameter
{
public AllRequestParameters(String name, String value)
{
super(name, value);
}
@Override
public boolean evaluateHttp(final HttpServletRewrite event, final EvaluationContext context)
{
HttpServletRequest request = event.getRequest();
Enumeration<?> parameterNames = request.getParameterNames();
while (parameterNames.hasMoreElements())
{
String name = parameterNames.nextElement().toString();
if (getNameExpression().parse(name).submit(event, context))
{
if (matchesValues(event, context, request, name))
{
return true;
}
}
}
return false;
}
private boolean matchesValues(Rewrite event, EvaluationContext context, final HttpServletRequest request,
final String name)
{
for (String contents : Arrays.asList(request.getParameterValues(name)))
{
if (!getValueExpression().parse(contents).submit(event, context))
{
return false;
}
}
return true;
}
}
@Override
public Set<String> getRequiredParameterNames()
{
Set<String> result = new LinkedHashSet<String>();
result.addAll(name.getRequiredParameterNames());
result.addAll(value.getRequiredParameterNames());
return result;
}
@Override
public void setParameterStore(ParameterStore store)
{
name.setParameterStore(store);
value.setParameterStore(store);
}
}