/*
 * 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 java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import io.undertow.attribute.ExchangeAttribute;
import io.undertow.server.HttpServerExchange;

Returns true if the given attribute is not null and not an empty string
Author:Stuart Douglas
/** * Returns true if the given attribute is not null and not an empty string * * @author Stuart Douglas */
public class ExistsPredicate implements Predicate { private final ExchangeAttribute attribute; ExistsPredicate(final ExchangeAttribute attribute) { this.attribute = attribute; } @Override public boolean resolve(final HttpServerExchange value) { final String att = attribute.readAttribute(value); if(att == null) { return false; } return !att.isEmpty(); } @Override public String toString() { return "exists( '" + attribute.toString() + "' )"; } public static class Builder implements PredicateBuilder { @Override public String name() { return "exists"; } @Override public Map<String, Class<?>> parameters() { final Map<String, Class<?>> params = new HashMap<>(); params.put("value", ExchangeAttribute.class); return params; } @Override public Set<String> requiredParameters() { return Collections.singleton("value"); } @Override public String defaultParameter() { return "value"; } @Override public Predicate build(final Map<String, Object> config) { ExchangeAttribute value = (ExchangeAttribute) config.get("value"); return new ExistsPredicate(value); } } }