content: package net.sf.expectit;
  
  /*
   * #%L
   * ExpectIt
   * %%
   * Copyright (C) 2014 Alexey Gavrilov and contributors
   * %%
   * 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.
   * #L%
   */
  
  import static net.sf.expectit.matcher.Matchers.contains;
  import static org.junit.Assert.assertEquals;
  
  import java.io.ByteArrayInputStream;
  import java.lang.management.ManagementFactory;
  import java.nio.channels.Selector;
  import java.util.concurrent.TimeUnit;
  import javax.management.AttributeNotFoundException;
  import javax.management.MBeanServer;
  import javax.management.ObjectName;
  import org.junit.Assume;
  import org.junit.Test;
  
  /**
   * Verifies that there is no resource leaks after using an instance of Expect.
   */
  public class ResourceLeakTest {
  
      /**
       * Gets the number of the open file descriptors via JMX.s
       */
      private long getOpenFileDescriptorCount() throws Exception {
          ObjectName os = new ObjectName("java.lang:type=OperatingSystem");
          MBeanServer server = ManagementFactory.getPlatformMBeanServer();
          try {
              return (Long) server.getAttribute(os, "OpenFileDescriptorCount");
          } catch (AttributeNotFoundException ok) {
              Assume.assumeNoException("OS doesn't support ope file descriptors parameter", ok);
              throw ok;
          }
      }
  
      @Test
      public void testFileDescriptorLeak() throws Exception {
          // initialize the NIO subsystem before using the Expect.
          Selector.open().close();
  
          long before = getOpenFileDescriptorCount();
          for (int i = 0; i < 100; i++) {
              String string = "abc" + i + "def";
              ByteArrayInputStream input = new ByteArrayInputStream(string.getBytes());
              Expect expect = new ExpectBuilder()
                      .withInputs(input)
                      .withTimeout(TestUtils.SMALL_TIMEOUT, TimeUnit.MILLISECONDS)
                      .build();
              expect.expect(contains(i + "d"));
              // close input and the expect instance
              input.close();
              expect.close();
          }
          long after = getOpenFileDescriptorCount();
          // the numbers of the open file descriptors must be the same after
          // closing the expect instance.
          assertEquals(before, after);
      }
  }
  