io.undertow.predicate.PredicateParser Maven / Gradle / Ivy
/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* 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 io.undertow.predicate;
import io.undertow.server.handlers.builder.PredicatedHandlersParser;
/**
* Parser that can build a predicate from a string representation. The underlying syntax is quite simple, and example is
* shown below:
*
*
* path["/MyPath"] or (method[value="POST"] and not headersPresent[value={Content-Type, "Content-Encoding"}, ignoreTrailer=true]
*
*
* The following boolean operators are built in, listed in order or precedence:
* - not
* - and
* - or
*
* They work pretty much as you would expect them to. All other tokens are taken
* to be predicate names. If the predicate does not require any parameters then the
* brackets can be omitted, otherwise they are mandatory.
*
* If a predicate is only being passed a single parameter then the parameter name can be omitted.
* Strings can be enclosed in optional double or single quotations marks, and quotation marks can be escaped using
* \".
*
* Array types are represented via a comma separated list of values enclosed in curly braces.
*
* TODO: should we use antlr (or whatever) here? I don't really want an extra dependency just for this...
*
* @author Stuart Douglas
*/
public class PredicateParser {
public static final Predicate parse(String string, final ClassLoader classLoader) {
return PredicatedHandlersParser.parsePredicate(string, classLoader);
}
}