// TODO: See if type safety can be improved here
@SuppressWarnings("unchecked")
public void read(DataInput in) throws IOException {
this.methodName = StringRecord.readString(in);
this.parameters = new IOReadableWritable[in.readInt()];
this.parameterClasses = new Class[parameters.length];
for (int i = 0; i < parameters.length; i++) {
// Read class name for parameter and try to get class to that name
final String className = StringRecord.readString(in);
try {
parameterClasses[i] = ClassUtils.getRecordByName(className);
} catch (ClassNotFoundException cnfe) {
throw new IOException(cnfe.toString());
}
// See if parameter is null
if (in.readBoolean()) {
try {
final String parameterClassName = StringRecord.readString(in);
final Class<? extends IOReadableWritable> parameterClass =
ClassUtils.getRecordByName(parameterClassName);
parameters[i] = parameterClass.newInstance();
} catch (IllegalAccessException iae) {
throw new IOException(iae.toString());
} catch (InstantiationException ie) {
throw new IOException(ie.toString());
} catch (ClassNotFoundException cnfe) {
throw new IOException(cnfe.toString());
}
// Object will do everything else on its own
parameters[i].read(in);
} else {
parameters[i] = null;
}
}
}
/**
* Returns a reference to the {@link FileSystem} instance for accessing the file system identified
* by the given {@link URI}.
*
* @param uri the {@link URI} identifying the file system
* @return a reference to the {@link FileSystem} instance for accessing the file system identified
* by the given {@link URI}.
* @throws IOException thrown if a reference to the file system instance could not be obtained
*/
public static FileSystem get(final URI uri) throws IOException {
FileSystem fs = null;
synchronized (SYNCHRONIZATION_OBJECT) {
if (uri.getScheme() == null) {
throw new IOException("FileSystem: Scheme is null. file:// or hdfs:// are schemes.");
}
final FSKey key = new FSKey(uri.getScheme(), uri.getAuthority());
// See if there is a file system object in the cache
if (CACHE.containsKey(key)) {
return CACHE.get(key);
}
// Try to create a new file system
if (!FSDIRECTORY.containsKey(uri.getScheme())) {
throw new IOException("No file system found with scheme " + uri.getScheme());
}
Class<? extends FileSystem> fsClass = null;
try {
fsClass = ClassUtils.getFileSystemByName(FSDIRECTORY.get(uri.getScheme()));
} catch (ClassNotFoundException e1) {
throw new IOException(StringUtils.stringifyException(e1));
}
try {
fs = fsClass.newInstance();
} catch (InstantiationException e) {
throw new IOException(StringUtils.stringifyException(e));
} catch (IllegalAccessException e) {
throw new IOException(StringUtils.stringifyException(e));
}
// Initialize new file system object
fs.initialize(uri);
// Add new file system object to cache
CACHE.put(key, fs);
}
return fs;
}
