BufferProtocol (Jython API documentation)

All Known Subinterfaces:

PyBuffer

All Known Implementing Classes:

Base1DBuffer, BaseArrayBuffer, BaseBuffer, BaseNIOBuffer, Py2kBuffer, PyArray, PyArrayDerived, PyByteArray, PyByteArrayDerived, PyMemoryView, PyShadowString, PyShadowStringDerived, PyString, PyStringDerived, PyUnicode, PyUnicodeDerived, SimpleBuffer, SimpleNIOBuffer, SimpleStringBuffer, SimpleWritableBuffer, Strided1DBuffer, Strided1DNIOBuffer, Strided1DWritableBuffer, SyspathArchive, ZeroByteBuffer
```
public interface BufferProtocol
```
Interface marking an object as capable of exposing its internal state as a PyBuffer.
A few objects implement BufferProtocol (e.g. by inheritance) but cannot actually provide their value as a PyBuffer. These should throw ClassCastException, permitting the idiom:
```
     try (PyBuffer buf = ((BufferProtocol) obj).getBuffer(PyBUF.SIMPLE)) {
         ... // Do something with buf
     } catch (ClassCastException e) {
         ... // expected bytes object or buffer not obj.getType()
     }
 
```
The catch is executed identically whether the cause is the explicit cast of obj or getBuffer, and the try-with-resources releases the buffer if one was obtained.

- Method Summary
  
  All Methods Instance Methods Abstract Methods
  Modifier and Type Method Description
  
  PyBuffer getBuffer(int flags)
  Method by which the consumer requests the buffer from the exporter.

- Method Detail
  - getBuffer
```
PyBuffer getBuffer(int flags)
            throws PyException,
                   java.lang.ClassCastException
```
    Method by which the consumer requests the buffer from the exporter. The consumer provides information on its ability to understand buffer navigation. Each consumer requesting a buffer in this way, when it has finished using it, should make a corresponding call to PyBuffer.release() on the buffer it obtained, or PyBuffer.close() using try-with-resources, since some objects alter their behaviour while buffers are exported.
    
    Parameters:
    
    flags - specifying features demanded and the navigational capabilities of the consumer
    
    Returns:
    
    exported buffer
    
    Throws:
    
    PyException - BufferError when expectations do not correspond with the buffer
    
    java.lang.ClassCastException - when the object only formally implements BufferProtocol