/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You 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 org.apache.commons.io.input;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertNotNull;
  import static org.junit.Assert.assertNull;
  import static org.junit.Assert.assertTrue;
  import static org.junit.Assert.fail;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.Reader;
  import java.nio.charset.Charset;
  
  import javax.xml.parsers.DocumentBuilderFactory;
  import javax.xml.parsers.ParserConfigurationException;
  
  import org.apache.commons.io.ByteOrderMark;
  import org.apache.commons.io.Charsets;
  import org.junit.Assert;
  import org.junit.Assume;
  import org.junit.Test;
  import org.w3c.dom.Document;
  import org.xml.sax.InputSource;
  import org.xml.sax.SAXException;
  
  /**
   * Test case for {@link BOMInputStream}.
   *
   * @version $Id: BOMInputStreamTest.java 1471765 2013-04-24 23:20:29Z sebb $
   */
  public class BOMInputStreamTest {
      //----------------------------------------------------------------------------
      //  Support code
      //----------------------------------------------------------------------------
  
      /**
       *  A mock InputStream that expects <code>close()</code> to be called.
       */
      private static class ExpectCloseInputStream extends InputStream {
          private boolean _closeCalled;
  
          public void assertCloseCalled() {
              assertTrue(_closeCalled);
          }
  
          @Override
          public void close() throws IOException {
              _closeCalled = true;
          }
  
          @Override
          public int read() throws IOException {
              return -1;
          }
      }
  
      private void assertData(final byte[] expected, final byte[] actual, final int len)
          throws Exception {
          assertEquals("length", expected.length, len);
          for (int ii = 0; ii < expected.length; ii++) {
              assertEquals("byte " + ii, expected[ii], actual[ii]);
          }
      }
  
      /**
       *  Creates the underlying data stream, with or without BOM.
       */
      private InputStream createUtf16BeDataStream(final byte[] baseData, final boolean addBOM) {
          byte[] data = baseData;
          if (addBOM) {
              data = new byte[baseData.length + 2];
              data[0] = (byte) 0xFE;
              data[1] = (byte) 0xFF;
              System.arraycopy(baseData, 0, data, 2, baseData.length);
          }
          return new ByteArrayInputStream(data);
      }
  
      /**
       *  Creates the underlying data stream, with or without BOM.
       */
     private InputStream createUtf16LeDataStream(final byte[] baseData, final boolean addBOM) {
         byte[] data = baseData;
         if (addBOM) {
             data = new byte[baseData.length + 2];
             data[0] = (byte) 0xFF;
             data[1] = (byte) 0xFE;
             System.arraycopy(baseData, 0, data, 2, baseData.length);
         }
         return new ByteArrayInputStream(data);
     }
 
     /**
      *  Creates the underlying data stream, with or without BOM.
      */
     private InputStream createUtf32BeDataStream(final byte[] baseData, final boolean addBOM) {
         byte[] data = baseData;
         if (addBOM) {
             data = new byte[baseData.length + 4];
             data[0] = 0;
             data[1] = 0;
             data[2] = (byte) 0xFE;
             data[3] = (byte) 0xFF;
             System.arraycopy(baseData, 0, data, 4, baseData.length);
         }
         return new ByteArrayInputStream(data);
     }
 
     /**
      *  Creates the underlying data stream, with or without BOM.
      */
     private InputStream createUtf32LeDataStream(final byte[] baseData, final boolean addBOM) {
         byte[] data = baseData;
         if (addBOM) {
             data = new byte[baseData.length + 4];
             data[0] = (byte) 0xFF;
             data[1] = (byte) 0xFE;
             data[2] = 0;
             data[3] = 0;
             System.arraycopy(baseData, 0, data, 4, baseData.length);
         }
         return new ByteArrayInputStream(data);
     }
 
     /**
      *  Creates the underlying data stream, with or without BOM.
      */
     private InputStream createUtf8DataStream(final byte[] baseData, final boolean addBOM) {
         byte[] data = baseData;
         if (addBOM) {
             data = new byte[baseData.length + 3];
             data[0] = (byte) 0xEF;
             data[1] = (byte) 0xBB;
             data[2] = (byte) 0xBF;
             System.arraycopy(baseData, 0, data, 3, baseData.length);
         }
         return new ByteArrayInputStream(data);
     }
 
     //----------------------------------------------------------------------------
     //  Test cases
     //----------------------------------------------------------------------------
 
     private void parseXml(final InputStream in) throws SAXException, IOException, ParserConfigurationException {
         final Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new InputSource(in));
         assertNotNull(doc);
         assertEquals("X", doc.getFirstChild().getNodeName());
     }
 
     private void parseXml(final Reader in) throws SAXException, IOException, ParserConfigurationException {
         final Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new InputSource(in));
         assertNotNull(doc);
         assertEquals("X", doc.getFirstChild().getNodeName());
     }
 
     private void readBOMInputStreamTwice(final String resource) throws Exception {
         final InputStream inputStream = this.getClass().getResourceAsStream(resource);
         Assert.assertNotNull(inputStream);
         final BOMInputStream bomInputStream = new BOMInputStream(inputStream);
         bomInputStream.mark(1000000);
 
         this.readFile(bomInputStream);
         bomInputStream.reset();
         this.readFile(bomInputStream);
     }
 
     private void readFile(final BOMInputStream bomInputStream) throws Exception {
         int bytes = 0;
         final byte[] bytesFromStream = new byte[100];
         do {
             bytes = bomInputStream.read(bytesFromStream);
         } while (bytes > 0);
     }
 
     @Test
     public void testAvailableWithBOM() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C', 'D' };
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, true));
         assertEquals(7, in.available());
         in.close();
     }
 
     @Test
     public void testAvailableWithoutBOM() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C', 'D' };
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, false));
         assertEquals(4, in.available());
         in.close();
     }
 
     @Test
     // this is here for coverage
     public void testClose() throws Exception {
         final ExpectCloseInputStream del = new ExpectCloseInputStream();
         final InputStream in = new BOMInputStream(del);
 
         in.close();
         del.assertCloseCalled();
     }
 
     @Test
     public void testEmptyBufferWithBOM() throws Exception {
         final byte[] data = new byte[] {};
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, true));
         final byte[] buf = new byte[1024];
         assertEquals(-1, in.read(buf));
         in.close();
     }
 
     @Test
     public void testEmptyBufferWithoutBOM() throws Exception {
         final byte[] data = new byte[] {};
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, false));
         final byte[] buf = new byte[1024];
         assertEquals(-1, in.read(buf));
         in.close();
     }
 
     @Test
     public void testGetBOMFirstThenRead() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C' };
         final BOMInputStream in = new BOMInputStream(createUtf8DataStream(data, true));
         assertEquals("getBOM", ByteOrderMark.UTF_8, in.getBOM());
         assertTrue("hasBOM()", in.hasBOM());
         assertTrue("hasBOM(UTF-8)", in.hasBOM(ByteOrderMark.UTF_8));
         assertEquals('A', in.read());
         assertEquals('B', in.read());
         assertEquals('C', in.read());
         assertEquals(-1, in.read());
         in.close();
     }
 
     @Test
     public void testGetBOMFirstThenReadInclude() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C' };
         final BOMInputStream in = new BOMInputStream(createUtf8DataStream(data, true), true);
         assertTrue("hasBOM()", in.hasBOM());
         assertTrue("hasBOM(UTF-8)", in.hasBOM(ByteOrderMark.UTF_8));
         assertEquals("getBOM", ByteOrderMark.UTF_8, in.getBOM());
         assertEquals(0xEF, in.read());
         assertEquals(0xBB, in.read());
         assertEquals(0xBF, in.read());
         assertEquals('A', in.read());
         assertEquals('B', in.read());
         assertEquals('C', in.read());
         assertEquals(-1, in.read());
         in.close();
     }
 
     @Test
     public void testLargeBufferWithBOM() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C' };
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, true));
         final byte[] buf = new byte[1024];
         assertData(data, buf, in.read(buf));
         in.close();
     }
 
     @Test
     public void testLargeBufferWithoutBOM() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C' };
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, false));
         final byte[] buf = new byte[1024];
         assertData(data, buf, in.read(buf));
         in.close();
     }
 
     @Test
     public void testLeadingNonBOMBufferedRead() throws Exception {
         final byte[] data = new byte[] { (byte) 0xEF, (byte) 0xAB, (byte) 0xCD };
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, false));
         final byte[] buf = new byte[1024];
         assertData(data, buf, in.read(buf));
         in.close();
     }
 
     @Test
     public void testLeadingNonBOMSingleRead() throws Exception {
         final byte[] data = new byte[] { (byte) 0xEF, (byte) 0xAB, (byte) 0xCD };
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, false));
         assertEquals(0xEF, in.read());
         assertEquals(0xAB, in.read());
         assertEquals(0xCD, in.read());
         assertEquals(-1, in.read());
         in.close();
     }
 
     @Test
     public void testMarkResetAfterReadWithBOM() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C', 'D' };
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, true));
         assertTrue(in.markSupported());
 
         in.read();
         in.mark(10);
 
         in.read();
         in.read();
         in.reset();
         assertEquals('B', in.read());
         in.close();
     }
 
     @Test
     public void testMarkResetAfterReadWithoutBOM() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C', 'D' };
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, false));
         assertTrue(in.markSupported());
 
         in.read();
         in.mark(10);
 
         in.read();
         in.read();
         in.reset();
         assertEquals('B', in.read());
         in.close();
     }
 
     @Test
     public void testMarkResetBeforeReadWithBOM() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C', 'D' };
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, true));
         assertTrue(in.markSupported());
 
         in.mark(10);
 
         in.read();
         in.read();
         in.reset();
         assertEquals('A', in.read());
         in.close();
     }
 
     @Test
     public void testMarkResetBeforeReadWithoutBOM() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C', 'D' };
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, false));
         assertTrue(in.markSupported());
 
         in.mark(10);
 
         in.read();
         in.read();
         in.reset();
         assertEquals('A', in.read());
         in.close();
     }
 
     @Test
     public void testNoBoms() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C' };
         try {
             new BOMInputStream(createUtf8DataStream(data, true), false, (ByteOrderMark[])null);
             fail("Null BOMs, expected IllegalArgumentException");
         } catch (final IllegalArgumentException e) {
             // expected
         }
         try {
             new BOMInputStream(createUtf8DataStream(data, true), false, new ByteOrderMark[0]);
             fail("Null BOMs, expected IllegalArgumentException");
         } catch (final IllegalArgumentException e) {
             // expected
         }
     }
 
     @Test
     public void testReadEmpty() throws Exception {
         final byte[] data = new byte[] {};
         final BOMInputStream in = new BOMInputStream(createUtf8DataStream(data, false));
         assertEquals(-1, in.read());
         assertFalse("hasBOM()", in.hasBOM());
         assertFalse("hasBOM(UTF-8)", in.hasBOM(ByteOrderMark.UTF_8));
         assertNull("getBOM", in.getBOM());
         in.close();
     }
 
     @Test
     public void testReadSmall() throws Exception {
         final byte[] data = new byte[] { 'A', 'B' };
         final BOMInputStream in = new BOMInputStream(createUtf8DataStream(data, false));
         assertEquals('A', in.read());
         assertEquals('B', in.read());
         assertEquals(-1, in.read());
         assertFalse("hasBOM()", in.hasBOM());
         assertFalse("hasBOM(UTF-8)", in.hasBOM(ByteOrderMark.UTF_8));
         assertNull("getBOM", in.getBOM());
         in.close();
     }
 
     @Test
     public void testReadTwiceWithBOM() throws Exception {
         this.readBOMInputStreamTwice("/org/apache/commons/io/testfileBOM.xml");
     }
 
     @Test
     public void testReadTwiceWithoutBOM() throws Exception {
         this.readBOMInputStreamTwice("/org/apache/commons/io/testfileNoBOM.xml");
     }
 
     @Test
     public void testReadWithBOMInclude() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C' };
         final BOMInputStream in = new BOMInputStream(createUtf8DataStream(data, true), true);
         assertEquals(0xEF, in.read());
         assertEquals(0xBB, in.read());
         assertEquals(0xBF, in.read());
         assertEquals('A', in.read());
         assertEquals('B', in.read());
         assertEquals('C', in.read());
         assertEquals(-1, in.read());
         assertTrue("hasBOM()", in.hasBOM());
         assertTrue("hasBOM(UTF-8)", in.hasBOM(ByteOrderMark.UTF_8));
         assertEquals("getBOM", ByteOrderMark.UTF_8, in.getBOM());
         in.close();
     }
 
     @Test
     public void testReadWithBOMUtf16Be() throws Exception {
         final byte[] data = "ABC".getBytes(Charsets.UTF_16BE);
         final BOMInputStream in = new BOMInputStream(createUtf16BeDataStream(data, true), ByteOrderMark.UTF_16BE);
         assertEquals(0, in.read());
         assertEquals('A', in.read());
         assertEquals(0, in.read());
         assertEquals('B', in.read());
         assertEquals(0, in.read());
         assertEquals('C', in.read());
         assertEquals(-1, in.read());
         assertTrue("hasBOM()", in.hasBOM());
         assertTrue("hasBOM(UTF-16BE)", in.hasBOM(ByteOrderMark.UTF_16BE));
         assertEquals("getBOM", ByteOrderMark.UTF_16BE, in.getBOM());
         try {
             in.hasBOM(ByteOrderMark.UTF_16LE);
             fail("Expected IllegalArgumentException");
         } catch (final IllegalArgumentException e) {
             // expected - not configured for UTF-16LE
         }
         in.close();
     }
 
     @Test
     public void testReadWithBOMUtf16Le() throws Exception {
         final byte[] data = "ABC".getBytes(Charsets.UTF_16LE);
         final BOMInputStream in = new BOMInputStream(createUtf16LeDataStream(data, true), ByteOrderMark.UTF_16LE);
         assertEquals('A', in.read());
         assertEquals(0, in.read());
         assertEquals('B', in.read());
         assertEquals(0, in.read());
         assertEquals('C', in.read());
         assertEquals(0, in.read());
         assertEquals(-1, in.read());
         assertTrue("hasBOM()", in.hasBOM());
         assertTrue("hasBOM(UTF-16LE)", in.hasBOM(ByteOrderMark.UTF_16LE));
         assertEquals("getBOM", ByteOrderMark.UTF_16LE, in.getBOM());
         try {
             in.hasBOM(ByteOrderMark.UTF_16BE);
             fail("Expected IllegalArgumentException");
         } catch (final IllegalArgumentException e) {
             // expected - not configured for UTF-16BE
         }
         in.close();
     }
 
     @Test
     public void testReadWithBOMUtf32Be() throws Exception {
         Assume.assumeTrue(Charset.isSupported("UTF_32BE"));
         final byte[] data = "ABC".getBytes("UTF_32BE");
         final BOMInputStream in = new BOMInputStream(createUtf32BeDataStream(data, true), ByteOrderMark.UTF_32BE);
         assertEquals(0, in.read());
         assertEquals(0, in.read());
         assertEquals(0, in.read());
         assertEquals('A', in.read());
         assertEquals(0, in.read());
         assertEquals(0, in.read());
         assertEquals(0, in.read());
         assertEquals('B', in.read());
         assertEquals(0, in.read());
         assertEquals(0, in.read());
         assertEquals(0, in.read());
         assertEquals('C', in.read());
         assertEquals(-1, in.read());
         assertTrue("hasBOM()", in.hasBOM());
         assertTrue("hasBOM(UTF-32BE)", in.hasBOM(ByteOrderMark.UTF_32BE));
         assertEquals("getBOM", ByteOrderMark.UTF_32BE, in.getBOM());
         try {
             in.hasBOM(ByteOrderMark.UTF_32LE);
             fail("Expected IllegalArgumentException");
         } catch (final IllegalArgumentException e) {
             // expected - not configured for UTF-32LE
         }
         in.close();
     }
 
     @Test
     public void testReadWithBOMUtf32Le() throws Exception {
         Assume.assumeTrue(Charset.isSupported("UTF_32LE"));
         final byte[] data = "ABC".getBytes("UTF_32LE");
         final BOMInputStream in = new BOMInputStream(createUtf32LeDataStream(data, true), ByteOrderMark.UTF_32LE);
         assertEquals('A', in.read());
         assertEquals(0, in.read());
         assertEquals(0, in.read());
         assertEquals(0, in.read());
         assertEquals('B', in.read());
         assertEquals(0, in.read());
         assertEquals(0, in.read());
         assertEquals(0, in.read());
         assertEquals('C', in.read());
         assertEquals(0, in.read());
         assertEquals(0, in.read());
         assertEquals(0, in.read());
         assertEquals(-1, in.read());
         assertTrue("hasBOM()", in.hasBOM());
         assertTrue("hasBOM(UTF-32LE)", in.hasBOM(ByteOrderMark.UTF_32LE));
         assertEquals("getBOM", ByteOrderMark.UTF_32LE, in.getBOM());
         try {
             in.hasBOM(ByteOrderMark.UTF_32BE);
             fail("Expected IllegalArgumentException");
         } catch (final IllegalArgumentException e) {
             // expected - not configured for UTF-32BE
         }
         in.close();
     }
 
     @Test
     public void testReadWithBOMUtf8() throws Exception {
         final byte[] data = "ABC".getBytes(Charsets.UTF_8);
         final BOMInputStream in = new BOMInputStream(createUtf8DataStream(data, true), ByteOrderMark.UTF_8);
         assertEquals('A', in.read());
         assertEquals('B', in.read());
         assertEquals('C', in.read());
         assertEquals(-1, in.read());
         assertTrue("hasBOM()", in.hasBOM());
         assertTrue("hasBOM(UTF-8)", in.hasBOM(ByteOrderMark.UTF_8));
         assertEquals("getBOM", ByteOrderMark.UTF_8, in.getBOM());
         try {
             in.hasBOM(ByteOrderMark.UTF_16BE);
             fail("Expected IllegalArgumentException");
         } catch (final IllegalArgumentException e) {
             // expected - not configured for UTF-16BE
         }
         in.close();
     }
 
     @Test
     public void testReadWithMultipleBOM() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C' };
         final BOMInputStream in = new BOMInputStream(createUtf8DataStream(data, true),
                                             ByteOrderMark.UTF_16BE, ByteOrderMark.UTF_8);
         assertEquals('A', in.read());
         assertEquals('B', in.read());
         assertEquals('C', in.read());
         assertEquals(-1, in.read());
         assertTrue("hasBOM()", in.hasBOM());
         assertTrue("hasBOM(UTF-8)", in.hasBOM(ByteOrderMark.UTF_8));
         assertFalse("hasBOM(UTF-16BE)", in.hasBOM(ByteOrderMark.UTF_16BE));
         assertEquals("getBOM", ByteOrderMark.UTF_8, in.getBOM());
         in.close();
     }
 
     @Test
     public void testReadWithoutBOM() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C' };
         final BOMInputStream in = new BOMInputStream(createUtf8DataStream(data, false));
         assertEquals('A', in.read());
         assertEquals('B', in.read());
         assertEquals('C', in.read());
         assertEquals(-1, in.read());
         assertFalse("hasBOM()", in.hasBOM());
         assertFalse("hasBOM(UTF-8)", in.hasBOM(ByteOrderMark.UTF_8));
         assertNull("getBOM", in.getBOM());
         in.close();
     }
 
     @Test
     public void testReadXmlWithBOMUcs2() throws Exception {
         // UCS-2 is BE.
         Assume.assumeTrue(Charset.isSupported("ISO-10646-UCS-2"));
         final byte[] data = "<?xml version=\"1.0\" encoding=\"ISO-10646-UCS-2\"?><X/>".getBytes("ISO-10646-UCS-2");
         parseXml(new BOMInputStream(createUtf16BeDataStream(data, true), ByteOrderMark.UTF_16BE));
         parseXml(createUtf16BeDataStream(data, true));
     }
 
     @Test
     public void testReadXmlWithBOMUcs4() throws Exception {
         // UCS-4 is BE or LE?
         // Hm: ISO-10646-UCS-4 is not supported on Oracle 1.6.0_31
         Assume.assumeTrue(Charset.isSupported("ISO-10646-UCS-4"));
         final byte[] data = "<?xml version=\"1.0\" encoding=\"ISO-10646-UCS-4\"?><X/>".getBytes("ISO-10646-UCS-4");
         // XML parser does not know what to do with UTF-32
         parseXml(new BOMInputStream(createUtf32BeDataStream(data, true), ByteOrderMark.UTF_32BE));
         // XML parser does not know what to do with UTF-32
         parseXml(createUtf32BeDataStream(data, true));
     }
 
     @Test
     public void testReadXmlWithBOMUtf16Be() throws Exception {
         final byte[] data = "<?xml version=\"1.0\" encoding=\"UTF-16BE\"?><X/>".getBytes(Charsets.UTF_16BE);
         parseXml(new BOMInputStream(createUtf16BeDataStream(data, true), ByteOrderMark.UTF_16BE));
         parseXml(createUtf16BeDataStream(data, true));
     }
 
     @Test
     public void testReadXmlWithBOMUtf16Le() throws Exception {
         final byte[] data = "<?xml version=\"1.0\" encoding=\"UTF-16LE\"?><X/>".getBytes(Charsets.UTF_16LE);
         parseXml(new BOMInputStream(createUtf16LeDataStream(data, true), ByteOrderMark.UTF_16LE));
         parseXml(createUtf16LeDataStream(data, true));
     }
 
     @Test
     public void testReadXmlWithBOMUtf32Be() throws Exception {
         Assume.assumeTrue(Charset.isSupported("UTF_32BE"));
         final byte[] data = "<?xml version=\"1.0\" encoding=\"UTF-32BE\"?><X/>".getBytes("UTF_32BE");
         parseXml(new BOMInputStream(createUtf32BeDataStream(data, true), ByteOrderMark.UTF_32BE));
         // XML parser does not know what to do with UTF-32, so we warp the input stream with a XmlStreamReader
         parseXml(new XmlStreamReader(createUtf32BeDataStream(data, true)));
     }
 
     @Test
     public void testReadXmlWithBOMUtf32Le() throws Exception {
         Assume.assumeTrue(Charset.isSupported("UTF_32LE"));
         final byte[] data = "<?xml version=\"1.0\" encoding=\"UTF-32LE\"?><X/>".getBytes("UTF_32LE");
         parseXml(new BOMInputStream(createUtf32LeDataStream(data, true), ByteOrderMark.UTF_32LE));
         // XML parser does not know what to do with UTF-32, so we warp the input stream with a XmlStreamReader
         parseXml(new XmlStreamReader(createUtf32LeDataStream(data, true)));
     }
 
     @Test
     public void testReadXmlWithBOMUtf8() throws Exception {
         final byte[] data = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><X/>".getBytes(Charsets.UTF_8);
         parseXml(new BOMInputStream(createUtf8DataStream(data, true)));
         parseXml(createUtf8DataStream(data, true));
     }
 
     @Test
     public void testReadXmlWithoutBOMUtf32Be() throws Exception {
         Assume.assumeTrue(Charset.isSupported("UTF_32BE"));
         final byte[] data = "<?xml version=\"1.0\" encoding=\"UTF-32BE\"?><X/>".getBytes("UTF_32BE");
         parseXml(new BOMInputStream(createUtf32BeDataStream(data, false)));
         parseXml(createUtf32BeDataStream(data, false));
     }
 
     @Test
     public void testReadXmlWithoutBOMUtf32Le() throws Exception {
         Assume.assumeTrue(Charset.isSupported("UTF_32LE"));
         final byte[] data = "<?xml version=\"1.0\" encoding=\"UTF-32LE\"?><X/>".getBytes("UTF_32LE");
         parseXml(new BOMInputStream(createUtf32LeDataStream(data, false)));
         parseXml(createUtf32BeDataStream(data, false));
     }
 
     @Test
     public void testSkipWithBOM() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C', 'D' };
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, true));
         in.skip(2L);
         assertEquals('C', in.read());
         in.close();
     }
 
     @Test
     public void testSkipWithoutBOM() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C', 'D' };
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, false));
         in.skip(2L);
         assertEquals('C', in.read());
         in.close();
     }
 
     @Test
     public void testSmallBufferWithBOM() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C' };
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, true));
         final byte[] buf = new byte[1024];
         assertData(new byte[] { 'A', 'B' }, buf, in.read(buf, 0, 2));
         assertData(new byte[] { 'C' }, buf, in.read(buf, 0, 2));
         in.close();
     }
 
     @Test
     public void testSmallBufferWithoutBOM() throws Exception {
         final byte[] data = new byte[] { 'A', 'B', 'C' };
         final InputStream in = new BOMInputStream(createUtf8DataStream(data, false));
         final byte[] buf = new byte[1024];
         assertData(new byte[] { 'A', 'B' }, buf, in.read(buf, 0, 2));
         assertData(new byte[] { 'C' }, buf, in.read(buf, 0, 2));
         in.close();
     }
 
     @Test
     // make sure that our support code works as expected
     public void testSupportCode() throws Exception {
         final InputStream in = createUtf8DataStream(new byte[] { 'A', 'B' }, true);
         final byte[] buf = new byte[1024];
         final int len = in.read(buf);
         assertEquals(5, len);
         assertEquals(0xEF, buf[0] & 0xFF);
         assertEquals(0xBB, buf[1] & 0xFF);
         assertEquals(0xBF, buf[2] & 0xFF);
         assertEquals('A', buf[3] & 0xFF);
         assertEquals('B', buf[4] & 0xFF);
 
         assertData(
                 new byte[] { (byte) 0xEF, (byte) 0xBB, (byte) 0xBF, 'A', 'B' },
                 buf, len);
     }
 }