org.apache.gobblin.util

Class ClassAliasResolver<T>

java.lang.Object

org.apache.gobblin.util.ClassAliasResolver<T>

@ThreadSafe
public class ClassAliasResolver<T>
extends Object

A class that scans through all classes in the classpath annotated with Alias and is a subType of subTypeOf constructor argument. It caches the alias to class mapping. Applications can call resolve(String) to resolve a class's alias to its cannonical name.
Note : If same alias is used for multiple classes in the classpath, the first mapping in classpath scan holds good. Subsequent ones will be logged and ignored.
Note: For the moment this class will only look for classes with gobblin/com.linkedin.gobblin prefix, as scanning the entire classpath is very expensive.

Constructor Summary

Constructors

Constructor and Description
ClassAliasResolver(Class<T> subTypeOf)

Method Summary

Modifier and Type	Method and Description
Map<String,Class<? extends T>>	getAliasMap() Get the map from found aliases to classes.
List<Alias>	getAliasObjects()
String	resolve(String possibleAlias) Resolves the given alias to its name if a mapping exits.
Class<? extends T>	resolveClass(String aliasOrClassName) Attempts to resolve the given alias to a class.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ClassAliasResolver

public ClassAliasResolver(Class<T> subTypeOf)

Method Detail

resolve

public String resolve(String possibleAlias)

Resolves the given alias to its name if a mapping exits. To create a mapping for a class, it has to be annotated with Alias

Parameters:

possibleAlias - to use for resolution.

Returns:

The name of the class with possibleAlias if mapping is available. Return the input possibleAlias if no mapping is found.

resolveClass

public Class<? extends T> resolveClass(String aliasOrClassName)
                                throws ClassNotFoundException

Attempts to resolve the given alias to a class. It first tries to find a class in the classpath with this alias and is also a subclass of subtypeOf, if it fails it returns a class object for name aliasOrClassName.

Throws:

ClassNotFoundException

getAliasMap

public Map<String,Class<? extends T>> getAliasMap()

Get the map from found aliases to classes.

getAliasObjects

public List<Alias> getAliasObjects()