com.baasbox.android

Interface DataStreamHandler<R>

Type Parameters:

R - the type of response that this stream handler will deliver

public interface DataStreamHandler<R>

Interface definition for a callback to be invoked when new data is available in an asynchronous streaming request.

This interface is used to handle the asynchronous streaming of files.

The callback is invoked on a background thread ant it may be invoked many times while the data is streamed from the server.
While the content is downloaded the data byte array will never be null and will contain new data received from the server.

When the streaming of the file ends, the callback will be invoked one more time with a null data byte array, that is an indication that the content has been completely retrieved from the server.

The return value of the last call to #onData(byte[], int, long, String, String) is what will be presented to the handler, wrapped in a BaasResult, if during any invocation an exception is thrown it will be wrapped as a BaasResult.failure(BaasException).

This is an example of streaming a response to a String:

     
         public class StreamToString implements DataStreamHandler<String>{
              private ByteArrayOutputStream out = new ByteArrayOutputStream();

             @Override
              public String onData(byte[] data,int read,long contentLength,String id,String contentType) throws Exception{
                  if(data!=null){
                      out.write(data,0,read);
                     return null;
                  } else{
                      return out.toString("UTF-8");
                  }
              }
         }
     
 

Since:

0.7.3

Method Summary

Modifier and Type	Method and Description
R	endData(java.lang.String id, long contentLength, java.lang.String contentType) Method invoked when the whole data has been streamed
void	finishStream(java.lang.String id)
void	onData(byte[] data, int read) Method invoked when new data is available.
void	startData(java.lang.String id, long contentLength, java.lang.String contentType) Method invoked right before data starts to stream.

Method Detail

startData

void startData(java.lang.String id,
               long contentLength,
               java.lang.String contentType)
        throws java.lang.Exception

Method invoked right before data starts to stream.

Parameters:

id - the identifier to which this stream is bound to

contentLength - the length of the body

contentType - the contentType of the response

Throws:

java.lang.Exception

onData

void onData(byte[] data,
            int read)
     throws java.lang.Exception

Method invoked when new data is available.

Parameters:

data - a byte[] array filled with new available data or null if there is no more available.

read - the number of actual bytes that can be read from data

Throws:

java.lang.Exception - any exception thrown will be wrapped in a BaasException

endData

R endData(java.lang.String id,
          long contentLength,
          java.lang.String contentType)
   throws java.lang.Exception

Method invoked when the whole data has been streamed

Parameters:

id - the identifier to which this stream is bound to

contentLength - the length of the body

contentType - the contentType of the response

Returns:

an object

Throws:

java.lang.Exception

finishStream

void finishStream(java.lang.String id)