org.lenskit.eval.traintest.metrics

Class MetricLoaderHelper

java.lang.Object

org.lenskit.eval.traintest.metrics.MetricLoaderHelper

public class MetricLoaderHelper
extends Object

Helper for loading metrics from the classpath.

Constructor Summary

Constructors

Constructor and Description
MetricLoaderHelper(ClassLoader cl, String baseName) Create a new loader helper.

Method Summary

Modifier and Type	Method and Description
<T> T	createMetric(Class<T> type, com.fasterxml.jackson.databind.JsonNode node)
<T> T	createMetric(Class<T> type, String json)
Class<?>	findClass(String name) Look up the class implementing a metric by name.
String	getMetricTypeName(com.fasterxml.jackson.databind.JsonNode node) Get the metric type name from a node.
Object	tryInstantiate(String name) Try to instantiate a metric.

Methods inherited from class java.lang.Object

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

Constructor Detail

MetricLoaderHelper

public MetricLoaderHelper(ClassLoader cl,
                          String baseName)
                   throws IOException

Create a new loader helper.

Parameters:

cl - The class loader.

baseName - The base name for files to look for; will load from META-INF/lenskit/baseName.properteis.

Throws:

IOException - If there is an error loading the properties.

Method Detail

findClass

@Nullable
public Class<?> findClass(String name)

Look up the class implementing a metric by name.

Parameters:

name - The metric name.

Returns:

The metric class.

tryInstantiate

public Object tryInstantiate(String name)

Try to instantiate a metric.

Parameters:

name - The metric name (case-insensitive; will be looked up in lowercase).

Returns:

The metric, or null if no such metric can be found.

getMetricTypeName

public String getMetricTypeName(com.fasterxml.jackson.databind.JsonNode node)

Get the metric type name from a node. If the node is a string, the string is returned; otherwise, the object’s type property is returned.

Parameters:

node - The node.

Returns:

The type name.

createMetric

@Nullable
public <T> T createMetric(Class<T> type,
                                     com.fasterxml.jackson.databind.JsonNode node)

createMetric

@Nullable
public <T> T createMetric(Class<T> type,
                                     String json)