001/**
002 * Copyright (C) 2006-2025 Talend Inc. - www.talend.com
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.talend.sdk.component.tools.validator;
017
018import static java.util.stream.Stream.of;
019
020import java.lang.reflect.Method;
021import java.util.List;
022import java.util.stream.Stream;
023
024import org.apache.xbean.finder.AnnotationFinder;
025import org.talend.sdk.component.api.processor.ElementListener;
026import org.talend.sdk.component.api.processor.Output;
027
028public class OutputConnectionValidator implements Validator {
029
030    @Override
031    public Stream<String> validate(final AnnotationFinder finder, final List<Class<?>> components) {
032        // outputs must have only one input param
033        return components
034                .stream()
035                .flatMap(c -> of(c.getMethods()).filter(m -> m.isAnnotationPresent(ElementListener.class)))
036                .filter(m -> of(m.getParameters()).noneMatch(p -> p.isAnnotationPresent(Output.class)))
037                .filter(m -> of(m.getParameters()).filter(p -> !p.isAnnotationPresent(Output.class)).count() > 1)
038                .map(Method::getDeclaringClass)
039                .distinct()
040                .map(clazz -> "The Output component '" + clazz
041                        + "' must have only one single input branch parameter in its ElementListener method.");
042    }
043}