org.springframework.beans.factory.config

Class YamlProcessor

java.lang.Object

org.springframework.beans.factory.config.YamlProcessor

Direct Known Subclasses:

YamlMapFactoryBean, YamlPropertiesFactoryBean

public abstract class YamlProcessor
extends Object

Base class for YAML factories.

Requires SnakeYAML 1.18 or higher, as of Spring Framework 5.0.6.

Since:

4.1

Author:

Dave Syer, Juergen Hoeller, Sam Brannen, Brian Clozel

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	YamlProcessor.DocumentMatcher Strategy interface used to test if properties match.
static interface	YamlProcessor.MatchCallback Callback interface used to process the YAML parsing results.
static class	YamlProcessor.MatchStatus Status returned from YamlProcessor.DocumentMatcher.matches(java.util.Properties).
static class	YamlProcessor.ResolutionMethod Method to use for resolving resources.

Constructor Summary

Constructors

Constructor and Description
YamlProcessor()

Method Summary

Modifier and Type	Method and Description
protected org.yaml.snakeyaml.Yaml	createYaml() Create the Yaml instance to use.
protected Map<String,Object>	getFlattenedMap(Map<String,Object> source) Return a flattened version of the given map, recursively following any nested Map or Collection values.
protected void	process(YamlProcessor.MatchCallback callback) Provide an opportunity for subclasses to process the Yaml parsed from the supplied resources.
void	setDocumentMatchers(YamlProcessor.DocumentMatcher... matchers) A map of document matchers allowing callers to selectively use only some of the documents in a YAML resource.
void	setMatchDefault(boolean matchDefault) Flag indicating that a document for which all the document matchers abstain will nevertheless match.
void	setResolutionMethod(YamlProcessor.ResolutionMethod resolutionMethod) Method to use for resolving resources.
void	setResources(Resource... resources) Set locations of YAML resources to be loaded.
void	setSupportedTypes(Class<?>... supportedTypes) Set the supported types that can be loaded from YAML documents.

Methods inherited from class java.lang.Object

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

Constructor Detail

YamlProcessor

public YamlProcessor()

Method Detail

setDocumentMatchers

public void setDocumentMatchers(YamlProcessor.DocumentMatcher... matchers)

A map of document matchers allowing callers to selectively use only some of the documents in a YAML resource. In YAML documents are separated by --- lines, and each document is converted to properties before the match is made. E.g.

 environment: dev
 url: https://dev.bar.com
 name: Developer Setup
 ---
 environment: prod
 url:https://foo.bar.com
 name: My Cool App
 

when mapped with

 setDocumentMatchers(properties ->
     ("prod".equals(properties.getProperty("environment")) ? MatchStatus.FOUND : MatchStatus.NOT_FOUND));
 

would end up as

 environment=prod
 url=https://foo.bar.com
 name=My Cool App
 

setMatchDefault

public void setMatchDefault(boolean matchDefault)

Flag indicating that a document for which all the document matchers abstain will nevertheless match. Default is true.

setResolutionMethod

public void setResolutionMethod(YamlProcessor.ResolutionMethod resolutionMethod)

Method to use for resolving resources. Each resource will be converted to a Map, so this property is used to decide which map entries to keep in the final output from this factory. Default is YamlProcessor.ResolutionMethod.OVERRIDE.

setResources

public void setResources(Resource... resources)

Set locations of YAML resources to be loaded.

See Also:

YamlProcessor.ResolutionMethod

setSupportedTypes

public void setSupportedTypes(Class<?>... supportedTypes)

Set the supported types that can be loaded from YAML documents.

If no supported types are configured, only Java standard classes (as defined in SafeConstructor) encountered in YAML documents will be supported. If an unsupported type is encountered, an IllegalStateException will be thrown when the corresponding YAML node is processed.

Parameters:

supportedTypes - the supported types, or an empty array to clear the supported types

Since:

5.1.16

See Also:

createYaml()

process

protected void process(YamlProcessor.MatchCallback callback)

Provide an opportunity for subclasses to process the Yaml parsed from the supplied resources. Each resource is parsed in turn and the documents inside checked against the matchers. If a document matches it is passed into the callback, along with its representation as Properties. Depending on the setResolutionMethod(ResolutionMethod) not all of the documents will be parsed.

Parameters:

callback - a callback to delegate to once matching documents are found

See Also:

createYaml()

createYaml

protected org.yaml.snakeyaml.Yaml createYaml()

Create the Yaml instance to use.

The default implementation sets the "allowDuplicateKeys" flag to false, enabling built-in duplicate key handling in SnakeYAML 1.18+.

As of Spring Framework 5.1.16, if custom supported types have been configured, the default implementation creates a Yaml instance that filters out unsupported types encountered in YAML documents. If an unsupported type is encountered, an IllegalStateException will be thrown when the node is processed.

See Also:

LoaderOptions.setAllowDuplicateKeys(boolean)

getFlattenedMap

protected final Map<String,Object> getFlattenedMap(Map<String,Object> source)

Return a flattened version of the given map, recursively following any nested Map or Collection values. Entries from the resulting map retain the same order as the source. When called with the Map from a YamlProcessor.MatchCallback the result will contain the same values as the YamlProcessor.MatchCallback Properties.

Parameters:

source - the source map

Returns:

a flattened map

Since:

4.1.3