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.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static class 
    ProxyOutputStream.Builder
    Builds instances of ProxyOutputStream.

  • Field Summary

    Fields inherited from class 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.
    ProxyOutputStream
    setReference(OutputStream out)
    Sets the underlying output stream.
    void
    write(byte[] b)
    Invokes the delegate's write(byte[]) method.
    void
    write(byte[] b, int off, int len)
    Invokes the delegate's write(byte[]) method.
    void
    write(int b)
    Invokes the delegate's write(int) method.
    void
    writeRepeat(byte[] b, int off, int len, long repeat)
    Invokes the delegate's write(byte[]) method for the repeat count.
    void
    writeRepeat(byte[] b, long repeat)
    Invokes the delegate's write(byte[]) method for the repeat count.
    void
    writeRepeat(int b, long repeat)
    Invokes the delegate's write(int) method.

    Methods inherited from class 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

    • setReference

      public ProxyOutputStream setReference(OutputStream out)
      Sets the underlying output stream.
      Parameters:
      out - the underlying output stream.
      Returns:
      this instance.
      Since:
      2.19.0

    • write

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

    • write

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

    • write

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

    • writeRepeat

      public void writeRepeat(byte[] b, int off, int len, long repeat) throws IOException
      Invokes the delegate's write(byte[]) method for the repeat count.
      Parameters:
      b - the bytes to write.
      off - The start offset.
      len - The number of bytes to write.
      repeat - How many times to write the bytes in b.
      Throws:
      IOException - if an I/O error occurs.
      Since:
      2.21.0

    • writeRepeat

      public void writeRepeat(byte[] b, long repeat) throws IOException
      Invokes the delegate's write(byte[]) method for the repeat count.
      Parameters:
      b - the bytes to write.
      repeat - How many times to write the bytes in b.
      Throws:
      IOException - if an I/O error occurs.
      Since:
      2.21.0

    • writeRepeat

      public void writeRepeat(int b, long repeat) throws IOException
      Invokes the delegate's write(int) method.
      Parameters:
      b - the byte to write.
      repeat - How many times to write the byte in b.
      Throws:
      IOException - if an I/O error occurs.
      Since:
      2.21.0