Package org.apache.commons.io.output

Class TaggedOutputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable
    public class TaggedOutputStream
extends ProxyOutputStream
    An output 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. 
     TaggedOutputStream stream = new TaggedOutputStream(...);
 try {
     // Processing that may throw an IOException either from this stream
     // or from some other IO activity like temporary files, etc.
     writeToStream(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(Exception) 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. 

     TaggedOutputStream stream = new TaggedOutputStream(...);
 try {
     writeToStream(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
      TaggedOutputStream​(java.io.OutputStream proxy)
      Creates a tagging decorator for the given output stream.

    • Method Summary

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

      • Methods inherited from class java.io.OutputStream

        nullOutputStream

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • TaggedOutputStream

        public TaggedOutputStream​(java.io.OutputStream proxy)
        Creates a tagging decorator for the given output stream.
        Parameters:
        proxy - output stream to be decorated

    • Method Detail

      • isCauseOf

        public boolean isCauseOf​(java.lang.Exception 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.Exception exception)
                    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:
        exception - an exception
        Throws:
        java.io.IOException - original exception, if any, thrown by this stream