Package org.apache.flink.table.functions

Class FunctionContext

java.lang.Object

org.apache.flink.table.functions.FunctionContext

@PublicEvolving
public class FunctionContext
extends Object

A FunctionContext allows to obtain global runtime information about the context in which the user-defined function is executed.

The information includes the metric group, distributed cache files, and global job parameters.

Note: Depending on the call location of a function, not all information might be available. For example, during constant expression reduction the function is executed locally with minimal information.

Constructor Summary

Constructors

Constructor	Description
FunctionContext(org.apache.flink.api.common.functions.RuntimeContext context)
FunctionContext(org.apache.flink.api.common.functions.RuntimeContext context, ClassLoader userClassLoader, org.apache.flink.api.common.functions.OpenContext openContext)

Method Summary

Modifier and Type	Method	Description
File	getCachedFile(String name)	Gets the local temporary file copy of a distributed cache files.
Set<org.apache.flink.api.common.externalresource.ExternalResourceInfo>	getExternalResourceInfos(String resourceName)	Get the external resource information.
String	getJobParameter(String key, String defaultValue)	Gets the global job parameter value associated with the given key as a string.
org.apache.flink.metrics.MetricGroup	getMetricGroup()	Returns the metric group for this parallel subtask.
ClassLoader	getUserCodeClassLoader()	Gets the ClassLoader to load classes that are not in system's classpath, but are part of the JAR file of a user job.

Methods inherited from class java.lang.Object

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

Constructor Detail

FunctionContext

public FunctionContext(@Nullable
                       org.apache.flink.api.common.functions.RuntimeContext context,
                       @Nullable
                       ClassLoader userClassLoader,
                       @Nullable
                       org.apache.flink.api.common.functions.OpenContext openContext)

FunctionContext

public FunctionContext(org.apache.flink.api.common.functions.RuntimeContext context)

Method Detail

getMetricGroup

public org.apache.flink.metrics.MetricGroup getMetricGroup()

Returns the metric group for this parallel subtask.

Returns:

metric group for this parallel subtask.

getCachedFile

public File getCachedFile(String name)

Gets the local temporary file copy of a distributed cache files.

Parameters:

name - distributed cache file name

Returns:

local temporary file copy of a distributed cache file.

getJobParameter

public String getJobParameter(String key,
                              String defaultValue)

Gets the global job parameter value associated with the given key as a string.

Parameters:

key - key pointing to the associated value

defaultValue - default value which is returned in case global job parameter is null or there is no value associated with the given key

Returns:

(default) value associated with the given key

getExternalResourceInfos

public Set<org.apache.flink.api.common.externalresource.ExternalResourceInfo> getExternalResourceInfos(String resourceName)

Get the external resource information.

getUserCodeClassLoader

public ClassLoader getUserCodeClassLoader()

Gets the ClassLoader to load classes that are not in system's classpath, but are part of the JAR file of a user job.