/**
* Utility method to get a FlowLoader implementation suitable for loading a flow with the supplied
* file extension.
*
* @param flowFileExtension the file extension to get a FlowLoader for
* @param log the log in use
* @return a FlowLoader
* @throws WekaException if a problem occurs
*/
public static FlowLoader getFlowLoader(String flowFileExtension, Logger log)
throws WekaException {
Set<String> availableLoaders =
PluginManager.getPluginNamesOfType(FlowLoader.class.getCanonicalName());
FlowLoader result = null;
if (availableLoaders != null) {
try {
for (String l : availableLoaders) {
FlowLoader candidate =
(FlowLoader) PluginManager.getPluginInstance(FlowLoader.class.getCanonicalName(), l);
if (candidate.getFlowFileExtension().equalsIgnoreCase(flowFileExtension)) {
result = candidate;
break;
}
}
} catch (Exception ex) {
throw new WekaException(ex);
}
}
if (result != null) {
result.setLog(log);
}
return result;
}
// register default loader for JSON flow files
static {
PluginManager.addPlugin(
FlowLoader.class.getCanonicalName(),
JSONFlowLoader.class.getCanonicalName(),
JSONFlowLoader.class.getCanonicalName(),
true);
// TODO temporary (move to a package later)
PluginManager.addPlugin(
FlowLoader.class.getCanonicalName(),
LegacyFlowLoader.class.getCanonicalName(),
LegacyFlowLoader.class.getCanonicalName(),
true);
Set<String> flowLoaders =
PluginManager.getPluginNamesOfType(FlowLoader.class.getCanonicalName());
if (flowLoaders != null) {
try {
for (String f : flowLoaders) {
FlowLoader fl =
(FlowLoader) PluginManager.getPluginInstance(FlowLoader.class.getCanonicalName(), f);
String extension = fl.getFlowFileExtension();
String description = fl.getFlowFileExtensionDescription();
FLOW_FILE_EXTENSIONS.add(
new ExtensionFileFilter("." + extension, description + " (*." + extension + ")"));
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
/**
* Utility method to load a flow from a file
*
* @param flowFile the file to load from
* @param log the log to use
* @return the loaded Flow
* @throws WekaException if a problem occurs
*/
public static Flow loadFlow(File flowFile, Logger log) throws WekaException {
String extension = "kf";
if (flowFile.toString().lastIndexOf('.') > 0) {
extension =
flowFile
.toString()
.substring(flowFile.toString().lastIndexOf('.') + 1, flowFile.toString().length());
}
FlowLoader toUse = getFlowLoader(extension, log);
if (toUse == null) {
throw new WekaException("Was unable to find a loader for flow file: " + flowFile.toString());
}
return toUse.readFlow(flowFile);
}
/**
* Utility method to load a flow from the supplied reader using the supplied FlowLoader
*
* @param r the reader to load from
* @param loader the FlowLoader to use
* @return the loaded flow
* @throws WekaException if a problem occurs
*/
public static Flow loadFlow(Reader r, FlowLoader loader) throws WekaException {
return loader.readFlow(r);
}
/**
* Utility method to load a flow from the supplied input stream using the supplied FlowLoader
*
* @param is the input stream to load from
* @param loader the FlowLoader to use
* @return the loaded Flow
* @throws WekaException if a problem occurs
*/
public static Flow loadFlow(InputStream is, FlowLoader loader) throws WekaException {
return loader.readFlow(is);
}
