Package javax.servlet

Class ServletInputStream

All Implemented Interfaces:
Closeable, AutoCloseable

public abstract class ServletInputStream extends InputStream
Provides an input stream for reading binary data from a client request, including an efficient readLine method for reading data one line at a time. With some protocols, such as HTTP POST and PUT, a ServletInputStream object can be used to read data sent from the client.

A ServletInputStream object is normally retrieved via the ServletRequest.getInputStream() method.

This is an abstract class that a servlet container implements. Subclasses of this class must implement the method.

See Also:
  • Constructor Details

    • ServletInputStream

      protected ServletInputStream()
      Does nothing, because this is an abstract class.
  • Method Details

    • readLine

      public int readLine(byte[] b, int off, int len) throws IOException
      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.

      This method returns -1 if it reaches the end of the input stream before reading the maximum number of bytes.

      b - an array of bytes into which data is read
      off - an integer specifying the character at which this method begins reading
      len - an integer specifying the maximum number of bytes to read
      an integer specifying the actual number of bytes read, or -1 if the end of the stream is reached
      IOException - if an input or output exception has occurred
    • isFinished

      public abstract boolean isFinished()
      Has the end of this InputStream been reached?
      true if all the data has been read from the stream, else false
      Servlet 3.1
    • isReady

      public abstract boolean isReady()
      Can data be read from this InputStream without blocking? Returns If this method is called and returns false, the container will invoke ReadListener.onDataAvailable() when data is available.
      true if data can be read without blocking, else false
      Servlet 3.1
    • setReadListener

      public abstract void setReadListener(ReadListener listener)
      Sets the ReadListener for this 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.
      listener - The non-blocking IO read listener
      IllegalStateException - If this method is called if neither async nor HTTP upgrade is in progress or if the ReadListener has already been set
      NullPointerException - If listener is null
      Servlet 3.1