Package org.apache.commons.io.input

Class TaggedInputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable
    public class TaggedInputStream
extends ProxyInputStream
    An input stream decorator that tags potential exceptions so that the stream that caused the exception can easily be identified. This is done by using the TaggedIOException class to wrap all thrown IOExceptions. See below for an example of using this class. 
     TaggedInputStream stream = new TaggedInputStream(...);
 try {
     // Processing that may throw an IOException either from this stream
     // or from some other IO activity like temporary files, etc.
     processStream(stream);
 } catch (IOException e) {
     if (stream.isCauseOf(e)) {
         // The exception was caused by this stream.
         // Use e.getCause() to get the original exception.
     } else {
         // The exception was caused by something else.
     }
 }

    Alternatively, the throwIfCauseOf(Throwable) method can be used to let higher levels of code handle the exception caused by this stream while other processing errors are being taken care of at this lower level. 

     TaggedInputStream stream = new TaggedInputStream(...);
 try {
     processStream(stream);
 } catch (IOException e) {
     stream.throwIfCauseOf(e);
     // ... or process the exception that was caused by something else
 }
    Since:
    2.0
    See Also:
    TaggedIOException

    • Constructor Summary

      Constructors 
      Constructor Description
      TaggedInputStream​(java.io.InputStream proxy)
      Creates a tagging decorator for the given input stream.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean isCauseOf​(java.lang.Throwable exception)
      Tests if the given exception was caused by this stream.
      void throwIfCauseOf​(java.lang.Throwable throwable)
      Re-throws the original exception thrown by this stream.

      • Methods inherited from class java.io.InputStream

        nullInputStream, readAllBytes, readNBytes, readNBytes, transferTo

      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • TaggedInputStream

        public TaggedInputStream​(java.io.InputStream proxy)
        Creates a tagging decorator for the given input stream.
        Parameters:
        proxy - input stream to be decorated

    • Method Detail

      • isCauseOf

        public boolean isCauseOf​(java.lang.Throwable exception)
        Tests if the given exception was caused by this stream.
        Parameters:
        exception - an exception
        Returns:
        true if the exception was thrown by this stream, false otherwise

      • throwIfCauseOf

        public void throwIfCauseOf​(java.lang.Throwable throwable)
                    throws java.io.IOException
        Re-throws the original exception thrown by this stream. This method first checks whether the given exception is a TaggedIOException wrapper created by this decorator, and then unwraps and throws the original wrapped exception. Returns normally if the exception was not thrown by this stream.
        Parameters:
        throwable - an exception
        Throws:
        java.io.IOException - original exception, if any, thrown by this stream