org.hibernate.search.util
Class PluginLoader

java.lang.Object
  org.hibernate.search.util.PluginLoader

public class PluginLoader
extends java.lang.Object

Utility class to load instances of other classes by using a fully qualified name, or from a class type. Uses reflection and throws SearchException(s) with proper descriptions of the error, like the target class is missing a proper constructor, is an interface, is not found...

Author:

Sanne Grinovero

Constructor Summary

PluginLoader()

Method Summary

static void	checkHasValidconstructor(java.lang.Class<?> classToLoad, java.lang.String componentDescription) Verifies if target class has a no-args constructor, and that it is accessible in current security manager.
static <T> T	instanceFromClass(java.lang.Class<T> targetSuperType, java.lang.Class<?> classToLoad, java.lang.String componentDescription) Creates an instance of target class
static <T> T	instanceFromName(java.lang.Class<T> targetSuperType, java.lang.String classNameToLoad, java.lang.Class<?> caller, java.lang.String componentDescription) Creates an instance of a target class designed by fully qualified name

Methods inherited from class java.lang.Object

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

Constructor Detail

PluginLoader

public PluginLoader()

Method Detail

instanceFromName

public static <T> T instanceFromName(java.lang.Class<T> targetSuperType,
                                     java.lang.String classNameToLoad,
                                     java.lang.Class<?> caller,
                                     java.lang.String componentDescription)

Creates an instance of a target class designed by fully qualified name

Type Parameters:

T - matches the type of targetSuperType: defines the return type

Parameters:

targetSuperType - the return type of the function, the classNameToLoad will be checked to be assignable to this type.

classNameToLoad - a fully qualified class name, whose type is assignable to targetSuperType

caller - the class of the caller, needed for classloading purposes

componentDescription - a meaningful description of the role the instance will have, used to enrich error messages to describe the context of the error

Returns:

a new instance of classNameToLoad

Throws:

SearchException - wrapping other error types with a proper error message for all kind of problems, like classNotFound, missing proper constructor, wrong type, security errors.

instanceFromClass

public static <T> T instanceFromClass(java.lang.Class<T> targetSuperType,
                                      java.lang.Class<?> classToLoad,
                                      java.lang.String componentDescription)

Creates an instance of target class

Type Parameters:

T - the type of targetSuperType: defines the return type

Parameters:

targetSuperType - the created instance will be checked to be assignable to this type

classToLoad - the class to be instantiated

componentDescription - a role name/description to contextualize error messages

Returns:

a new instance of classToLoad

Throws:

SearchException - wrapping other error types with a proper error message for all kind of problems, like missing proper constructor, wrong type, security errors.

checkHasValidconstructor

public static void checkHasValidconstructor(java.lang.Class<?> classToLoad,
                                            java.lang.String componentDescription)

Verifies if target class has a no-args constructor, and that it is accessible in current security manager.

Parameters:

classToLoad - the class type to check

componentDescription - adds a meaningful description to the type to describe in the exception message