Class QueueInputStream

java.lang.Object
java.io.InputStream
org.apache.commons.io.input.QueueInputStream
All Implemented Interfaces:
Closeable, AutoCloseable

public class QueueInputStream extends InputStream
Simple alternative to JDK PipedInputStream; queue input stream provides what's written in queue output stream.

To build an instance, use QueueInputStream.Builder.

Example usage:

 QueueInputStream inputStream = new QueueInputStream();
 QueueOutputStream outputStream = inputStream.newQueueOutputStream();

 outputStream.write("hello world".getBytes(UTF_8));
 inputStream.read();
 

Unlike JDK PipedInputStream and PipedOutputStream, queue input/output streams may be used safely in a single thread or multiple threads. Also, unlike JDK classes, no special meaning is attached to initial or current thread. Instances can be used longer after initial threads exited.

Closing a QueueInputStream has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.

Since:
2.9.0
See Also:
  • Constructor Details

  • Method Details

    • builder

      Constructs a new QueueInputStream.Builder.
      Returns:
      a new QueueInputStream.Builder.
      Since:
      2.12.0
    • newQueueOutputStream

      Constructs a new QueueOutputStream instance connected to this. Writes to the output stream will be visible to this input stream.
      Returns:
      QueueOutputStream connected to this stream.
    • read

      public int read()
      Reads and returns a single byte.
      Specified by:
      read in class InputStream
      Returns:
      the byte read, or -1 if a timeout occurs before a queue element is available.
      Throws:
      IllegalStateException - if thread is interrupted while waiting.
    • read

      public int read(byte[] b, int offset, int length)
      Reads up to length bytes of data from the input stream into an array of bytes. The first byte is read while honoring the timeout; the rest are read while not honoring the timeout. The number of bytes actually read is returned as an integer.
      Overrides:
      read in class InputStream
      Parameters:
      b - the buffer into which the data is read.
      offset - the start offset in array b at which the data is written.
      length - the maximum number of bytes to read.
      Returns:
      the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.
      Throws:
      NullPointerException - If b is null.
      IllegalStateException - if thread is interrupted while waiting for the first byte.
      IndexOutOfBoundsException - if offset is negative, length is negative, or length is greater than b.length - offset.
      Since:
      2.20.0