ExampleFilter.java

/*
 * Copyright 2016 the original author or authors.
 *
 * 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 filters;

import akka.stream.Materializer;
import java.util.concurrent.CompletionStage;
import java.util.concurrent.Executor;
import java.util.function.Function;
import javax.inject.*;
import play.mvc.*;
import play.mvc.Http.RequestHeader;

@Singleton
public class ExampleFilter extends Filter {

    private final Executor exec;

    @Inject
    public ExampleFilter(Materializer mat, Executor exec) {
        super(mat);
        this.exec = exec;
    }

    @Override
    public CompletionStage<Result> apply(
            Function<RequestHeader, CompletionStage<Result>> next,
            RequestHeader requestHeader) {

        return next.apply(requestHeader).thenApplyAsync(
                result -> result.withHeader("X-ExampleFilter", "foo"),
                exec);
    }
}