test/jdk/java/nio/channels/spi/SelectorProvider/TestDefaultImplementation.java

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/*
 * @test
 * @bug 8254692
 * @summary Basic test for java.nio.channels.spi.SelectorProvider.java default implementation
 * @run testng TestDefaultImplementation
 */

import org.testng.annotations.Test;

import java.io.IOException;
import java.net.ProtocolFamily;
import java.nio.channels.*;
import java.nio.channels.spi.AbstractSelector;
import java.nio.channels.spi.SelectorProvider;

import static org.testng.Assert.assertNull;
import static org.testng.Assert.assertThrows;

public class TestDefaultImplementation {
    static final Class<UnsupportedOperationException> UOE = UnsupportedOperationException.class;
    static final Class<NullPointerException> NPE = NullPointerException.class;
    static final ProtocolFamily BAD_PF = () -> "BAD_PROTOCOL_FAMILY";

    @Test
    public void testSelectorProvider() throws IOException {
        CustomSelectorProviderImpl customSpi = new CustomSelectorProviderImpl();

        assertNull(customSpi.inheritedChannel());

        assertThrows(NPE, () -> customSpi.openSocketChannel(null));
        assertThrows(NPE, () -> customSpi.openServerSocketChannel(null));

        assertThrows(UOE, () -> customSpi.openSocketChannel(BAD_PF));
        assertThrows(UOE, () -> customSpi.openServerSocketChannel(BAD_PF));
    }

    // A concrete subclass of SelectorProvider, in order to test the
    // default java.nio.channels.spi.SelectorProvider implementation
    static class CustomSelectorProviderImpl extends SelectorProvider {
        @Override public DatagramChannel openDatagramChannel() { return null; }
        @Override public DatagramChannel openDatagramChannel(ProtocolFamily family) { return null; }
        @Override public Pipe openPipe() { return null; }
        @Override public AbstractSelector openSelector() { return null; }
        @Override public ServerSocketChannel openServerSocketChannel() { return null; }
        @Override public SocketChannel openSocketChannel() { return null; }
    }
}