public static synchronized HBaseCompat getCompat(String classOverride) {
if (null != cachedCompat) {
log.debug("Returning cached HBase compatibility layer: {}", cachedCompat);
return cachedCompat;
}
HBaseCompat compat;
String className = null;
String classNameSource = null;
if (null != classOverride) {
className = classOverride;
classNameSource = "from explicit configuration";
} else {
String hbaseVersion = VersionInfo.getVersion();
for (String supportedVersion : Arrays.asList("0.94", "0.96", "0.98", "1.0")) {
if (hbaseVersion.startsWith(supportedVersion + ".")) {
className =
"com.thinkaurelius.titan.diskstorage.hbase.HBaseCompat"
+ supportedVersion.replaceAll("\\.", "_");
classNameSource = "supporting runtime HBase version " + hbaseVersion;
break;
}
}
if (null == className) {
log.info(
"The HBase version {} is not explicitly supported by Titan. "
+ "Loading Titan's compatibility layer for its most recent supported HBase version ({})",
hbaseVersion,
DEFAULT_HBASE_COMPAT_VERSION);
className = DEFAULT_HBASE_CLASS_NAME;
classNameSource = " by default";
}
}
final String errTemplate = " when instantiating HBase compatibility class " + className;
try {
compat = (HBaseCompat) Class.forName(className).newInstance();
log.info(
"Instantiated HBase compatibility layer {}: {}",
classNameSource,
compat.getClass().getCanonicalName());
} catch (IllegalAccessException e) {
throw new RuntimeException(e.getClass().getSimpleName() + errTemplate, e);
} catch (InstantiationException e) {
throw new RuntimeException(e.getClass().getSimpleName() + errTemplate, e);
} catch (ClassNotFoundException e) {
throw new RuntimeException(e.getClass().getSimpleName() + errTemplate, e);
}
return cachedCompat = compat;
}
private Object autoInstantiateEmbeddedInstance(Class<?> type) {
Object created = null;
try {
created = type.newInstance();
} catch (InstantiationException e) {
LOG.error(
String.format(
"Unable to auto-create type %s, %s thrown in constructor", type, e.getClass()));
} catch (IllegalAccessException e) {
LOG.error(String.format("Unable to auto-create type %s, cannot access constructor", type));
}
return created;
}