public boolean markSupported() {
  return false;
 }

 public synchronized void reset() throws IOException {
  throw new IOException("mark/reset not supported");
 }

/*
 * 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 javax.servlet;

import java.io.IOException;
import java.io.InputStream;

/**
 * Provides an input stream for reading binary data from a client request,
 * including an efficient <code>readLine</code> method for reading data one line
 * at a time. With some protocols, such as HTTP POST and PUT, a
 * <code>ServletInputStream</code> object can be used to read data sent from the
 * client.
 * <p>
 * A <code>ServletInputStream</code> object is normally retrieved via the
 * {@link ServletRequest#getInputStream} method.
 * <p>
 * This is an abstract class that a servlet container implements. Subclasses of
 * this class must implement the <code>java.io.InputStream.read()</code> method.
 *
 * @see ServletRequest
 */
public abstract class ServletInputStream extends InputStream {

 /**
  * Does nothing, because this is an abstract class.
  */
 protected ServletInputStream() {
  // NOOP
 }

 /**
  * Reads the input stream, one line at a time. Starting at an offset, reads
  * bytes into an array, until it reads a certain number of bytes or reaches
  * a newline character, which it reads into the array as well.
  * <p>
  * This method returns -1 if it reaches the end of the input stream before
  * reading the maximum number of bytes.
  *
  * @param b
  *   an array of bytes into which data is read
  * @param off
  *   an integer specifying the character at which this method
  *   begins reading
  * @param len
  *   an integer specifying the maximum number of bytes to read
  * @return an integer specifying the actual number of bytes read, or -1 if
  *   the end of the stream is reached
  * @exception IOException
  *    if an input or output exception has occurred
  */
 public int readLine(byte[] b, int off, int len) throws IOException {

  if (len <= 0) {
   return 0;
  }
  int count = 0, c;

  while ((c = read()) != -1) {
   b[off++] = (byte) c;
   count++;
   if (c == '\n' || count == len) {
    break;
   }
  }
  return count > 0 ? count : -1;
 }

 /**
  * Returns <code>true</code> if all the data has been read from the stream,
  * else <code>false</code>.
  *
  * @since Servlet 3.1
  */
 public abstract boolean isFinished();

 /**
  * Returns <code>true</code> if data can be read without blocking, else
  * <code>false</code>. If this method is called and returns false, the
  * container will invoke {@link ReadListener#onDataAvailable()} when data is
  * available.
  *
  * @since Servlet 3.1
  */
 public abstract boolean isReady();

 /**
  * Sets the {@link ReadListener} for this {@link ServletInputStream} and
  * thereby switches to non-blocking IO. It is only valid to switch to
  * non-blocking IO within async processing or HTTP upgrade processing.
  *
  * @param listener The non-blocking IO read listener
  *
  * @throws IllegalStateException If this method is called if neither
  *         async nor HTTP upgrade is in progress or
  *         if the {@link ReadListener} has already
  *         been set
  * @throws NullPointerException  If listener is null
  *
  * @since Servlet 3.1
  */
 public abstract void setReadListener(ReadListener listener);
}