Package org.apache.tika.io

Class TaggedInputStream

java.lang.Object
java.io.InputStream
java.io.FilterInputStream
org.apache.tika.io.ProxyInputStream
org.apache.tika.io.TaggedInputStream
All Implemented Interfaces:
Closeable, AutoCloseable
Direct Known Subclasses:
TikaInputStream
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(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. 

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

  • Constructor Details

    • TaggedInputStream

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

  • Method Details

    • get

      public static TaggedInputStream get(InputStream proxy)
      Casts or wraps the given stream to a TaggedInputStream instance.
      Parameters:
      proxy - normal input stream
      Returns:
      a TaggedInputStream instance

    • isCauseOf

      public boolean isCauseOf(IOException 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(Exception exception) throws 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:
      IOException - original exception, if any, thrown by this stream

    • toString

      public String toString()
      Overrides:
      toString in class Object