com.mulesoft.connectivity.rest.commons.api.operation.paging

Class RestPagingProvider

java.lang.Object

com.mulesoft.connectivity.rest.commons.api.operation.paging.RestPagingProvider

All Implemented Interfaces:

org.mule.runtime.extension.api.runtime.streaming.PagingProvider<RestConnection,org.mule.runtime.api.metadata.TypedValue<String>>

Direct Known Subclasses:

MarkerPagingProvider, OffsetPagingProvider, PageNumberPagingProvider

public abstract class RestPagingProvider
extends Object
implements org.mule.runtime.extension.api.runtime.streaming.PagingProvider<RestConnection,org.mule.runtime.api.metadata.TypedValue<String>>

Provides the base functionality for paginating the results of a REST endpoint.

Different APIs use different paging strategies which are tackled in implementations of this class. This class provides the basics as:

• Executing one request per page to be obtained
• Ability to parse the response to extract the data and useful metadata as the total results count (if provided)
• Handling streaming
• Handling the nuances of the PagingProvider contract
• Handling encodings and media types

Each item in the obtained page will be returned as an individual TypedValue, with the proper mime type and encoding set.

Since:

1.0

Field Summary

Fields

Modifier and Type	Field and Description
protected org.mule.runtime.api.metadata.MediaType	defaultMediaType
protected org.mule.runtime.api.el.ExpressionLanguage	expressionLanguage
protected int	responseTimeout

Constructor Summary

Constructors

Constructor and Description
RestPagingProvider(Function<RestConnection,RestRequestBuilder> requestFactory, org.mule.runtime.api.el.ExpressionLanguage expressionLanguage, org.mule.runtime.extension.api.runtime.streaming.StreamingHelper streamingHelper, String payloadExpression, org.mule.runtime.api.metadata.MediaType defaultMediaType, int responseTimeout) Creates a new instance

Method Summary

Modifier and Type	Method and Description
void	close(RestConnection connection)
protected abstract void	configureRequest(RestRequestBuilder requestBuilder) Depending on the paging strategy, different parameters or headers may need to be passed.
protected void	doClose(RestConnection connection) Invoked when close(RestConnection) is invoked
protected <T> org.mule.runtime.api.metadata.TypedValue<T>	evaluate(org.mule.runtime.api.metadata.TypedValue<String> content, String expression, org.mule.runtime.api.metadata.DataType expectedOutputType, HttpResponseAttributes httpResponseAttributes)
List<org.mule.runtime.api.metadata.TypedValue<String>>	getPage(RestConnection connection)
Optional<Integer>	getTotalResults(RestConnection connection)
protected void	onPage(List<org.mule.runtime.api.metadata.TypedValue<String>> page, org.mule.runtime.api.metadata.TypedValue<String> rawPage, HttpResponseAttributes responseAttributes) Invoked each time a page is obtained.
protected void	stopPaging()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.mule.runtime.extension.api.runtime.streaming.PagingProvider

useStickyConnections

Field Detail

expressionLanguage

protected final org.mule.runtime.api.el.ExpressionLanguage expressionLanguage

responseTimeout

protected final int responseTimeout

defaultMediaType

protected final org.mule.runtime.api.metadata.MediaType defaultMediaType

Constructor Detail

RestPagingProvider

public RestPagingProvider(Function<RestConnection,RestRequestBuilder> requestFactory,
                          org.mule.runtime.api.el.ExpressionLanguage expressionLanguage,
                          org.mule.runtime.extension.api.runtime.streaming.StreamingHelper streamingHelper,
                          String payloadExpression,
                          org.mule.runtime.api.metadata.MediaType defaultMediaType,
                          int responseTimeout)

Creates a new instance

Parameters:

requestFactory - a Function to generate the request to be used on each page request. Each invocation should yield a different instance

expressionLanguage - the app's ExpressionLanguage

streamingHelper - the StreamingHelper associated to the executing operation

payloadExpression - a DW expression to extract the data from the response

defaultMediaType - the MediaType for the page items if the server doesn't specify one

responseTimeout - the timeout for each request

Method Detail

configureRequest

protected abstract void configureRequest(RestRequestBuilder requestBuilder)

Depending on the paging strategy, different parameters or headers may need to be passed. This method receives the raw output of the requestFactory in order to configure the custom parameters that apply/

Parameters:

requestBuilder - a RestRequestBuilder

getPage

public final List<org.mule.runtime.api.metadata.TypedValue<String>> getPage(RestConnection connection)

Specified by:

getPage in interface org.mule.runtime.extension.api.runtime.streaming.PagingProvider<RestConnection,org.mule.runtime.api.metadata.TypedValue<String>>

getTotalResults

public Optional<Integer> getTotalResults(RestConnection connection)

Specified by:

getTotalResults in interface org.mule.runtime.extension.api.runtime.streaming.PagingProvider<RestConnection,org.mule.runtime.api.metadata.TypedValue<String>>

close

public final void close(RestConnection connection)
                 throws org.mule.runtime.api.exception.MuleException

Specified by:

close in interface org.mule.runtime.extension.api.runtime.streaming.PagingProvider<RestConnection,org.mule.runtime.api.metadata.TypedValue<String>>

Throws:

org.mule.runtime.api.exception.MuleException

onPage

protected void onPage(List<org.mule.runtime.api.metadata.TypedValue<String>> page,
                      org.mule.runtime.api.metadata.TypedValue<String> rawPage,
                      HttpResponseAttributes responseAttributes)

Invoked each time a page is obtained.

Parameters:

page - the obtained page

stopPaging

protected void stopPaging()

doClose

protected void doClose(RestConnection connection)
                throws org.mule.runtime.api.exception.MuleException

Invoked when close(RestConnection) is invoked

Parameters:

connection - the current connection

Throws:

org.mule.runtime.api.exception.MuleException

evaluate

protected <T> org.mule.runtime.api.metadata.TypedValue<T> evaluate(org.mule.runtime.api.metadata.TypedValue<String> content,
                                                                   String expression,
                                                                   org.mule.runtime.api.metadata.DataType expectedOutputType,
                                                                   HttpResponseAttributes httpResponseAttributes)