Package org.apache.commons.io.output

Class ProxyOutputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable
    Direct Known Subclasses:
    CloseShieldOutputStream, CountingOutputStream, TaggedOutputStream, TeeOutputStream
    public class ProxyOutputStream
extends java.io.FilterOutputStream
    A Proxy stream which acts as expected, that is it passes the method calls on to the proxied stream and doesn't change which methods are being called. It is an alternative base class to FilterOutputStream to increase reusability.

    See the protected methods for ways in which a subclass can easily decorate a stream with custom pre-, post- or error processing functionality.

    • Field Summary

      • Fields inherited from class java.io.FilterOutputStream

        out

    • Constructor Summary

      Constructors 
      Constructor Description
      ProxyOutputStream​(java.io.OutputStream proxy)
      Constructs a new ProxyOutputStream.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected void afterWrite​(int n)
      Invoked by the write methods after the proxied call has returned successfully.
      protected void beforeWrite​(int n)
      Invoked by the write methods before the call is proxied.
      void close()
      Invokes the delegate's close() method.
      void flush()
      Invokes the delegate's flush() method.
      protected void handleIOException​(java.io.IOException e)
      Handle any IOExceptions thrown.
      void write​(byte[] bts)
      Invokes the delegate's write(byte[]) method.
      void write​(byte[] bts, int st, int end)
      Invokes the delegate's write(byte[]) method.
      void write​(int idx)
      Invokes the delegate's write(int) method.

      • Methods inherited from class java.io.OutputStream

        nullOutputStream

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • ProxyOutputStream

        public ProxyOutputStream​(java.io.OutputStream proxy)
        Constructs a new ProxyOutputStream.
        Parameters:
        proxy - the OutputStream to delegate to

    • Method Detail

      • write

        public void write​(int idx)
           throws java.io.IOException
        Invokes the delegate's write(int) method.
        Overrides:
        write in class java.io.FilterOutputStream
        Parameters:
        idx - the byte to write
        Throws:
        java.io.IOException - if an I/O error occurs.

      • write

        public void write​(byte[] bts)
           throws java.io.IOException
        Invokes the delegate's write(byte[]) method.
        Overrides:
        write in class java.io.FilterOutputStream
        Parameters:
        bts - the bytes to write
        Throws:
        java.io.IOException - if an I/O error occurs.

      • write

        public void write​(byte[] bts,
                  int st,
                  int end)
           throws java.io.IOException
        Invokes the delegate's write(byte[]) method.
        Overrides:
        write in class java.io.FilterOutputStream
        Parameters:
        bts - the bytes to write
        st - The start offset
        end - The number of bytes to write
        Throws:
        java.io.IOException - if an I/O error occurs.

      • flush

        public void flush()
           throws java.io.IOException
        Invokes the delegate's flush() method.
        Specified by:
        flush in interface java.io.Flushable
        Overrides:
        flush in class java.io.FilterOutputStream
        Throws:
        java.io.IOException - if an I/O error occurs.

      • close

        public void close()
           throws java.io.IOException
        Invokes the delegate's close() method.
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Overrides:
        close in class java.io.FilterOutputStream
        Throws:
        java.io.IOException - if an I/O error occurs.

      • beforeWrite

        protected void beforeWrite​(int n)
                    throws java.io.IOException
        Invoked by the write methods before the call is proxied. The number of bytes to be written (1 for the write(int) method, buffer length for write(byte[]), etc.) is given as an argument.

        Subclasses can override this method to add common pre-processing functionality without having to override all the write methods. The default implementation does nothing.

        Parameters:
        n - number of bytes to be written
        Throws:
        java.io.IOException - if the pre-processing fails
        Since:
        2.0

      • afterWrite

        protected void afterWrite​(int n)
                   throws java.io.IOException
        Invoked by the write methods after the proxied call has returned successfully. The number of bytes written (1 for the write(int) method, buffer length for write(byte[]), etc.) is given as an argument.

        Subclasses can override this method to add common post-processing functionality without having to override all the write methods. The default implementation does nothing.

        Parameters:
        n - number of bytes written
        Throws:
        java.io.IOException - if the post-processing fails
        Since:
        2.0

      • handleIOException

        protected void handleIOException​(java.io.IOException e)
                          throws java.io.IOException
        Handle any IOExceptions thrown.

        This method provides a point to implement custom exception handling. The default behavior is to re-throw the exception.

        Parameters:
        e - The IOException thrown
        Throws:
        java.io.IOException - if an I/O error occurs.
        Since:
        2.0