org.apache.flink.runtime.rest.messages

Class MessageParameter<X>

java.lang.Object

org.apache.flink.runtime.rest.messages.MessageParameter<X>

Direct Known Subclasses:

MessagePathParameter, MessageQueryParameter

public abstract class MessageParameter<X>
extends Object

This class represents a single path/query parameter that can be used for a request. Every parameter has an associated key, and a one-time settable value.

Parameters are either mandatory or optional, indicating whether the parameter must be resolved for the request.

All parameters support symmetric conversion from their actual type and string via convertFromString(String) and convertToString(Object). The conversion from X to string is required on the client to assemble the URL, whereas the conversion from string to X is required on the server to provide properly typed parameters to the handlers.

See Also:

MessagePathParameter, MessageQueryParameter

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	MessageParameter.MessageParameterRequisiteness Enum for indicating whether a parameter is mandatory or optional.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	MessageParameter(String key, MessageParameter.MessageParameterRequisiteness requisiteness)

Method Summary

Modifier and Type	Method and Description
protected abstract X	convertFromString(String value) Converts the given string to a valid value of this parameter.
protected abstract String	convertToString(X value) Converts the given value to its string representation.
abstract String	getDescription() Returns a description for REST API HTML documentation.
String	getKey() Returns the key of this parameter, e.g.
X	getValue() Returns the resolved value of this parameter, or null if it isn't resolved yet.
boolean	isMandatory() Returns whether this parameter must be resolved for the request.
boolean	isResolved() Returns whether this parameter has been resolved.
void	resolve(X value) Resolves this parameter for the given value.
void	resolveFromString(String value) Resolves this parameter for the given string value representation.

Methods inherited from class java.lang.Object

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

Constructor Detail

MessageParameter

protected MessageParameter(String key,
                           MessageParameter.MessageParameterRequisiteness requisiteness)

Method Detail

isResolved

public final boolean isResolved()

Returns whether this parameter has been resolved.

Returns:

true, if this parameter was resolved, false otherwise

resolve

public final void resolve(X value)

Resolves this parameter for the given value.

Parameters:

value - value to resolve this parameter with

resolveFromString

public final void resolveFromString(String value)
                             throws ConversionException

Resolves this parameter for the given string value representation.

Parameters:

value - string representation of value to resolve this parameter with

Throws:

ConversionException

convertFromString

protected abstract X convertFromString(String value)
                                throws ConversionException

Converts the given string to a valid value of this parameter.

Parameters:

value - string representation of parameter value

Returns:

parameter value

Throws:

ConversionException

convertToString

protected abstract String convertToString(X value)

Converts the given value to its string representation.

Parameters:

value - parameter value

Returns:

string representation of typed value

getKey

public final String getKey()

Returns the key of this parameter, e.g. "jobid".

Returns:

key of this parameter

getValue

public final X getValue()

Returns the resolved value of this parameter, or null if it isn't resolved yet.

Returns:

resolved value, or null if it wasn't resolved yet

isMandatory

public final boolean isMandatory()

Returns whether this parameter must be resolved for the request.

Returns:

true if the parameter is mandatory, false otherwise

getDescription

public abstract String getDescription()

Returns a description for REST API HTML documentation.

Returns:

escaped HTML string