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public interface ClassPathLoader
Interface for loading classpath objects to a specified location.

Classpath loaders are required to load implementation dependent classpath files to a given file system location. They are stateful objects, as they can be optinally queried if the previously loaded classpath state have changed.

Implementations can implement caching functionality to avoid loading the same classpath to the same location multiple times.

public default boolean
Checks if the classpath have changed at the location specified by this loader.
public SakerPath
Loads this classpath to the given directory.
public default boolean isChanged()
Checks if the classpath have changed at the location specified by this loader.

Implementations should determine if the classpath which this loader loads has changed or not. If this method returns true, the load manager should attempt to reload the classpath by calling loadTo(ProviderHolderPathKey) again (but not required to do so).

This method is generally useful when developing classpath implementations. A classpath is loaded by the build system, and a build is executed using it. The user might decide to replace the classpath implementation, by developing it further. The previously loaded classpath was cached by the build system, so it needs to determine if it has changed. By calling this method, it can see that it has changed, and attempt to reload the new implementation.
Note: Implementing this method will not guarantee that any classpath is reloaded. If multiple clients use the same classpath, it won't be reloaded, as they all need to be closed first.

The default implementation returns false.

true if the classpath should be reloaded.
public abstract SakerPath loadTo(ProviderHolderPathKey directory) throws IOException
Loads this classpath to the given directory.

The result of this operation can be a directory containing the classes in the respective package subdirectories, or a JAR file containing the classes to be loaded.

The operation can use appropriate caching not to load the same contents over and over again.

Subclasses are responsible to copy/download/replicate every resource necessary for the classpath to operate. Meaning that all class files and resources on the classpath should be present after this operation so that no class loading error occurs. Note that additional resources which are dynamically linked to these classes are not required to be present after this operation completes, they can and should be placed on-demand to a determined storage directory. (This directory can vary based on classpath use-cases.)

directoryThe directory to load the classpath to.
The relative path from the parameter directory to the loaded classpath classes.
IOExceptionIf the operation failed.