/*

 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package org.openjdk.tests.java.util.stream;

/*

 * THE CONTENTS OF THIS FILE HAVE TO BE IN SYNC WITH THE EXAMPLES USED

 * IN THE JAVADOC.

 *

 * @test

 * @bug 8231161

 * @compile CollectorExample.java

 * @summary Compilation test only. Compile code snippets from

 * java.util.stream.Collector class-level API documentation

 */

import java.util.*;

import java.util.function.BiConsumer;

import java.util.function.BinaryOperator;

import java.util.function.Function;

import java.util.function.Supplier;

import java.util.stream.Collector;

import java.util.stream.Collectors;

public class CollectorExample {

    // Empty helper classes

    class Widget {

    }

    class Employee {

        public int getSalary() {

            return 0;    // money isn't everything

        }

        public Department getDepartment() {

            return new Department();

        }

    }

    class Department {

    }

    <T, A, R> void testSnippet1(Collector<T, A, R> collector, T t1, T t2) {

        Supplier<A> supplier = collector.supplier();

        BiConsumer<A, T> accumulator = collector.accumulator();

        BinaryOperator<A> combiner = collector.combiner();

        Function<A, R> finisher = collector.finisher();

        // Example start

        A a1 = supplier.get();

        accumulator.accept(a1, t1);

        accumulator.accept(a1, t2);

        R r1 = finisher.apply(a1);

        A a2 = supplier.get();

        accumulator.accept(a2, t1);

        A a3 = supplier.get();

        accumulator.accept(a3, t2);

        R r2 = finisher.apply(combiner.apply(a2, a3));

    }

    void testSnippet2() {

        Collector<Widget, ?, TreeSet<Widget>> intoSet =

                Collector.of(TreeSet::new, TreeSet::add,

                        (left, right) -> { left.addAll(right); return left; });

    }

    <T, A, R> void testSnippet3(Collector<T, A, R> collector, Collection<T> data) {

        A container = collector.supplier().get();

        for (T t : data)

            collector.accumulator().accept(container, t);

        collector.finisher().apply(container);

    }

    void testSnippet4and5() {

        Collector<Employee, ?, Integer> summingSalaries

                = Collectors.summingInt(Employee::getSalary);

        Collector<Employee, ?, Map<Department, Integer>> summingSalariesByDept

                = Collectors.groupingBy(Employee::getDepartment, summingSalaries);

    }

}