io.undertow.predicate.ExistsPredicate Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of wildfly-client-all

This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

There is a newer version: 34.0.0.Final

Show newest version

/*
 * 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
 */
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> parameters() {
            final Map> params = new HashMap<>();
            params.put("value", ExchangeAttribute.class);
            return params;
        }

        @Override
        public Set requiredParameters() {
            return Collections.singleton("value");
        }

        @Override
        public String defaultParameter() {
            return "value";
        }

        @Override
        public Predicate build(final Map config) {
            ExchangeAttribute value = (ExchangeAttribute) config.get("value");
            return new ExistsPredicate(value);
        }
    }
}