Package org.apache.commons.io.output

Class ProxyOutputStream

java.lang.Object
java.io.OutputStream
java.io.FilterOutputStream
org.apache.commons.io.output.ProxyOutputStream
All Implemented Interfaces:
Closeable, Flushable, AutoCloseable
Direct Known Subclasses:
CloseShieldOutputStream, CountingOutputStream, TaggedOutputStream, TeeOutputStream
public class ProxyOutputStream extends 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(OutputStream delegate)
    Constructs a new ProxyOutputStream.

  • Method Summary

    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(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.lang.Object

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

  • Constructor Details

    • ProxyOutputStream

      public ProxyOutputStream(OutputStream delegate)
      Constructs a new ProxyOutputStream.
      Parameters:
      delegate - the OutputStream to delegate to

  • Method Details

    • afterWrite

      protected void afterWrite(int n) throws 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:
      IOException - if the post-processing fails
      Since:
      2.0

    • beforeWrite

      protected void beforeWrite(int n) throws 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:
      IOException - if the pre-processing fails
      Since:
      2.0

    • close

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

    • flush

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

    • handleIOException

      protected void handleIOException(IOException e) throws 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:
      IOException - if an I/O error occurs.
      Since:
      2.0

    • write

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

    • write

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

    • write

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