如何对Socket和OutputStreamWriter进行JUnit测试

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.mockito.Mockito;

import java.io.OutputStreamWriter;
import java.net.Socket;

import static org.mockito.Mockito.*;

public class SocketWriterTest {

    private Socket mockSocket;
    private OutputStreamWriter mockOutputStreamWriter;

    @BeforeEach
    public void setUp() throws Exception {
        mockSocket = Mockito.mock(Socket.class);
        mockOutputStreamWriter = Mockito.mock(OutputStreamWriter.class);
        when(mockSocket.getOutputStream()).thenReturn(mockOutputStreamWriter);
    }

    @Test
    public void testWriteToSocket() throws Exception {
        String message = "Hello, World!";
        SocketWriter socketWriter = new SocketWriter(mockSocket);

        socketWriter.write(message);

        verify(mockOutputStreamWriter).write(message);
        verify(mockOutputStreamWriter).flush();
    }

    // 假设的SocketWriter类
    private static class SocketWriter {
        private final Socket socket;

        public SocketWriter(Socket socket) {
            this.socket = socket;
        }

        public void write(String message) throws Exception {
            try (OutputStreamWriter writer = new OutputStreamWriter(socket.getOutputStream())) {
                writer.write(message);
                writer.flush();
            }
        }
    }
}