org.javarosa.core.reference

Interface Reference

All Known Implementing Classes:

ResourceReference

public interface Reference

A Reference is essentially a pointer to interact in a limited fashion with an external resource of some kind (images, xforms, etc). References are retrieved from the ReferenceManager, which is responsible for turning different URI's (either normal http://, etc URI's or JavaRosa jr:// URI's) into a reference to an actual resource.

Author:

ctsims

Method Summary

Modifier and Type	Method and Description
boolean	doesBinaryExist()
String	getLocalURI()
OutputStream	getOutputStream()
InputStream	getStream()
String	getURI()
boolean	isReadOnly()
Reference[]	probeAlternativeReferences() Determines any platform-specific and reference-type specific alternatives versions of this reference which may exist.
void	remove() Removes the binary data located by this reference.

Method Detail

doesBinaryExist

boolean doesBinaryExist()
                 throws IOException

Returns:

True if the binary does (or might) exist at the remote location. False if the binary definitely does not exist.

Throws:

IOException - If there is a problem identifying the status of the resource

getStream

InputStream getStream()
               throws IOException

Returns:

A Stream of data which is the binary resource's definition.

Throws:

IOException - If there is a problem reading the stream.

getURI

String getURI()

Returns:

A URI which will evaluate to this same reference in the future.

getLocalURI

String getLocalURI()

Returns:

A URI which may or may not exist in the local context which will resolves to this reference. This method should be used with caution: There is no guarantee that a local URI can be constructed or used in a general way.

isReadOnly

boolean isReadOnly()

Returns:

True if the remote data is only available to be read from (using getStream), False if the remote data can also be modified or written to.

getOutputStream

OutputStream getOutputStream()
                      throws IOException

Returns:

A stream which can be written to at the reference location to define the binary content there.

Throws:

IOException - If there is a problem writing or the reference is read only

remove

void remove()
     throws IOException

Removes the binary data located by this reference.

Throws:

IOException - If there is a problem deleting or the reference is read only

probeAlternativeReferences

Reference[] probeAlternativeReferences()

Determines any platform-specific and reference-type specific alternatives versions of this reference which may exist. Useful when only certain media or references are available on a platform and you need to figure out whether a platform-specific version might be present. NOTE: There is no guarantee that returned references will exist, they should be tested.