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()
      Returns true when all the data from the stream has been read else it returns false.
      true when all data for this particular request has been read, otherwise returns false.
      Servlet 3.1
    • isReady

      public abstract boolean isReady()
      Returns true if data can be read without blocking else returns false.
      true if data can be obtained without blocking, otherwise returns false.
      Servlet 3.1
    • setReadListener

      public abstract void setReadListener​(ReadListener readListener)
      Instructs the ServletInputStream to invoke the provided ReadListener when it is possible to read
      readListener - the ReadListener that should be notified when it's possible to read.
      IllegalStateException - if one of the following conditions is true
      • the associated request is neither upgraded nor the async started
      • setReadListener is called more than once within the scope of the same request.
      NullPointerException - if readListener is null
      Servlet 3.1