net.openhft.chronicle.core.pool

Interface ClassLookup

All Known Implementing Classes:

ClassAliasPool

public interface ClassLookup

An interface for looking up classes by name and associating them with aliases. This can be useful for reducing verbosity in configurations or serialization, or for dynamically loading classes in a flexible way.

Implementations of this interface should handle the logic for aliasing classes and provide a mechanism for looking up classes by either their canonical name or an associated alias.

Method Summary

Modifier and Type	Method and Description
void	addAlias(Class<?>... classes) Adds one or more classes to the class lookup.
void	addAlias(Class<?> clazz, String names) Adds a class to the class lookup with one or more specified aliases.
default CharSequence	applyAlias(CharSequence name) Applies an alias transformation to the given class name if an alias exists.
Class<?>	forName(CharSequence name) Looks up and returns the Class object associated with the given class name.
String	nameFor(Class<?> clazz) Retrieves the alias for the given class.
default @NotNull ClassLookup	wrap() Creates a new ClassLookup instance that wraps this instance.
default @NotNull ClassLookup	wrap(@NotNull ClassLoader classLoader) Creates a new ClassLookup instance that wraps this instance and uses the provided class loader to look up new classes.

Method Detail

wrap

@NotNull
default @NotNull ClassLookup wrap()

Creates a new ClassLookup instance that wraps this instance. Any changes made to the returned ClassLookup will not affect this instance.

Returns:

a new ClassLookup instance wrapping this ClassLookup, ensuring that the underlying instance remains immutable.

wrap

@NotNull
default @NotNull ClassLookup wrap(@NotNull
                                           @NotNull ClassLoader classLoader)

Creates a new ClassLookup instance that wraps this instance and uses the provided class loader to look up new classes. Any changes made to the returned ClassLookup will not affect this instance.

Parameters:

classLoader - The ClassLoader used to look up new classes.

Returns:

a new ClassLookup instance wrapping this ClassLookup and using the provided ClassLoader, ensuring that the underlying instance remains immutable.

Throws:

NullPointerException - if classLoader is null.

forName

Class<?> forName(CharSequence name)
          throws ClassNotFoundRuntimeException

Looks up and returns the Class object associated with the given class name.

Parameters:

name - The fully qualified name of the desired class.

Returns:

The Class object representing the specified class.

Throws:

ClassNotFoundRuntimeException - If the class cannot be located.

nameFor

String nameFor(Class<?> clazz)
        throws IllegalArgumentException

Retrieves the alias for the given class. This method is intended for use with non-lambda classes. For lambda classes, this method will throw an IllegalArgumentException.

Parameters:

clazz - The class to retrieve the alias for.

Returns:

A String representing the alias for the given class.

Throws:

IllegalArgumentException - If this method is used on a lambda function.

addAlias

void addAlias(Class<?>... classes)

Adds one or more classes to the class lookup. For each class, its simple name (excluding package) is automatically added as the alias.

Parameters:

classes - The classes to be added to the class lookup.

addAlias

void addAlias(Class<?> clazz,
              String names)

Adds a class to the class lookup with one or more specified aliases. The aliases can be provided as a comma-separated string and may include the package name.

Parameters:

clazz - The class to be added to the class lookup.

names - A single alias or a comma-separated string of aliases for the class.

applyAlias

default CharSequence applyAlias(CharSequence name)

Applies an alias transformation to the given class name if an alias exists. This method searches for an alias of the specified class name and returns the alias if found. If no alias is found, it returns the original class name. This mechanism allows for the flexible use of aliases in place of fully qualified class names, simplifying the referencing of classes within an application.

This method first looks up the provided class name in the internal alias mappings. If a direct match is found, it returns the corresponding class name as registered in the alias. If no direct match is found, it attempts to find a match using a case-insensitive search. This dual-step lookup ensures that aliases can be effectively used regardless of case sensitivity. If after both steps no alias is found, the method returns the original class name, ensuring that the operation is always safe and will not result in a loss of reference.

Usage of this method can significantly reduce the verbosity of class references in scenarios where short, memorable aliases are preferred over full class names. It is particularly useful in configuration files, dynamic class loading scenarios, or any context where class names are used as strings and brevity or clarity is desired.

Parameters:

name - The CharSequence representing the class name or alias to be transformed.

Returns:

A CharSequence representing the aliased class name if an alias exists, or the original class name if no alias is found. This ensures that the method never returns null or an invalid class name.

Throws:

NullPointerException - if the provided name is null.

See Also:

for how aliases are added to the pool.