JSR 382 Configuration in Java Standards and More

https://maketechsimple.wordpress.com@atsticks
JSR 382: Configuration in Java
Standards and More…
Anatole Tresch, Principal Consultant ZH AD

2
Agenda
• What is Configuration?
• Lifecycle and Runtimes
• Backends
• Configuration Services
• How to use it in your projects?
26.06.2019 Configuration in Java2

Anatole Tresch
Principal Consultant, Trivadis AG (Switzerland)
Spec Lead JSR 352 (Money and Currency)
JSR 382 EG Member
PPMC Member Apache Tamaya
@atsticks
anatole@apache.org
anatole.tresch@trivadis.com
3
About me

5
Wikipedia: Configuration
“In computing, configuration defines parameters and settings that control behavior
of some computer programs. They are used for user applications, server processes
and operating system settings and may change during runtime.”
System
Input Output
Config

6
Wikipedia: Configuration Files
“In computing, configuration files (or config files) are files used to configure the
parameters and initial settings for some computer programs. They are used for user
applications, server processes and operating system settings.”

Ohne Worte…

9
Configuration Files: xml
• Very verbose

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Configuration Files: properties
• No explicit support for
hierarchies, lists etc.
• Pure i18n support
• Pure Multiline support

11
Configuration Files: json
• It’s for machines not humans!
• Strictly: no comments

12
• Portability Issues
• Multiline values
Configuration Files: yaml

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• https://hjson.org/
• Advantages of JSON
• Easy for humans
Configuration Files: hjson

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Like HJSON, but even simpler
https://github.com/lightbend/config
Configuration Files: hocon
{
a : A
b : B
c : C
d {
o: O
p: P
}
}

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Configuration Lifecycle
and
Configuration Runtimes

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Configuration Lifecycle
• Development
• Build time
• Deployment time
• Runtime A Configuration Runtime System must
support all of them!

Configuration Runtime
• A programmatic model of Configuration Data
• A programmatic API to access Configuration Data
• An SPI for extending and customizing
• Optional:
• A predefined lifecycle of configuration data
• Integration with other frameworks, e.g.
Spring, JakartaEE, OSGI, plain Java, …

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Some Configuration Runtime Solutions…
• Apache Commons Config
• Apache Tamaya
• Apache Deltaspike
• Netflix Archaius Config
• Typesafe Config
• Microprofile.io
• Spring
• JSR 382
• Jakarta EEConfig ?
• ...

RIP JSR 382
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https://www.jcp.org/en/jsr/detail?id=382

Microprofile
• Part of MicroProfile.io project
• JSR 382 Code has been moved here
• Minimum viable solution:
• Configuration can live outside of an application.
• Ready for Microservice and container environments.
• Different Locations and Formats
• Dynamic change is possible.
• A @ConfigProperty annotation for CDI (incl. default values).
• String/String key/value, types through Converters
• A Config API to function without CDI.
• Current Release 1.3 (part of MP 2.2)
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https://github.com/eclipse/microprofile-config

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Apache Tamaya
• Result of first Standardization Attempt in 2013
• Minimum viable solution:
• Basically similar to JSR 382/Microprofile
• Full SE API
• Mature
• Tree value model for more powerful type, conversion & filtering mechanisms
• With modular extensions:
• A @Config annotation for injection (works with Spring, CDI and more)
• Multiple formats (props, xml, json, hjson, yaml, hocon, ini)
• Integration with Spring, OSGI, Camel, Vertx and more
• Metaconfig, Documentation (sandbox)
http://tamaya.apache.org

Accessing Configuration
Apache Tamaya
• Version 0.3-incubating, ALv2-Licence
• http://tamaya.incubator.apache.org
• Latest Release: org.apache.tamaya:tamaya-core:0.3-incubating
Examples here: 0.4-incubating-SNAPSHOT
• API & Core: https://github.com/apache/incubator-tamaya
• Extensions: https://github.com/apache/incubator-tamaya-extensions
• Sandbox: https://github.com/apache/incubator-tamaya-sandbox
Apache Snapshot Repo:
https://repository.apache.org/content/repositories/snapshots

23
Helidon
• Part of Oracle’s Microservice Framework
• Authors are the same as in JSR discussion of 2016
<dependency>
<groupId>io.helidon.config</groupId>
<artifactId>helidon-config</artifactId>
<version>version-of-config-you-are-using</version>
</dependency>
https://helidon.io/

Let’s dive deeper…
…into Code
…to the APIs…

Apache Tamaya
Microprofile
• Simple Text Key/Value Pairs
• Optional Conversion
Configuration Data – Accessing Properties

Configuration Data – Optional Values
Apache Tamaya
Microprofile

Configuration Data - Defaults
In Apache Tamaya additionally possible:
Microprofile

Configuration Data – Multikey Lookup
Apache Tamaya

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Configuration Data – Configuration Injection
Apache Tamaya
Microprofile
• Tamaya also supports
multikey-lookup with injection

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Configuration Data – Snapshots
Microprofile
Update: ConfigAccessor -> ConfigAccessorBuilder

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Configuration Data – Snapshots
Apache Tamaya

Configuration Data - Builders
Microprofile

Configuration Data - Builders
Apache Tamaya
• Tamaya has also functonality for removing/reordering of existing SPI artifacts.
• Filters are not supported by the JSR as of now.

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Configuration Backends (SPI) – Basic Idea
Config Runtime
Backends
Configuration Data
(Files, Servers etc.)
«Backends are are the
adapters between the
config system and your
Configuration Data»

Config Backend SPI – Config-/PropertySources
Apache TamayaMicroprofile

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Configuration Services
Config Runtime
Backends
Config Services
«Services (extensions)
provide additional
funtionality or runtime
integrations»

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Example Services
• Placeholders and calculated values: ${host.name}
• ANT styled file and resource patterns: classpath:**/*.yml
• Functional operators and queries (extract subsections, printing)
• Change events and mutability
• Additional configuration formats
• Integration with Spring, CDI, OSGI, Vertx, ….
• PropertySources for Consul, etcd etc
• …
Microprofile does not define any
services.

Example Service: Templates

Example Service: Placeholder resolution
Apache Tamaya
• When the tamaya-resolver
extension is installed, resolution
is transparent.

Example Service: Functional Operators
• Filtering and Printing with
the tamaya-functions extension.

Design Helidon.io

Design in 120 Seconds...
• Tamaya
ConfigurationContext
PropertyFilters
ConfigSources
Microprofile
ServiceContextManager
PropertySources
String Value
Typed Value
ConfigProvider
ServiceContext
PropertyValue
Tamaya
Typed Value
PropertyValue:
- Simple
- Array
- Map
+ Metadata
PropertyValue
PropertySourceProvider
ConfigSourceProvider
<create>
<create>
ConfigurationProviderSpi
ConfigProviderResolver
+ ConversionContext
+ FilterContext
ConfigAccessor

Configuration SPI – Tamaya Value Tree
• Matches structures as defined by yaml, json, xml configuration files.
• Allows complex mappings, e.g. multi-value based collections and complex
custom types
• Mapping to properties still possible (and OOTB supported).
PropertyValue
+ value: String
+ metadata: Map<String,String>
ObjectValue
+ fields: Map<String,PropertyValue>
ListValue
+ children: List<PropertyValue>

Configuration SPI – Type Converters
Microprofile

Configuration SPI – Type Converters
Apache Tamaya
• Tamaya’s PropertyConverters have additional access to a ConversionContext

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Example: Tamaya and Spring?

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1. Add Dependencies to your Project
<dependency>
<groupId>org.apache.tamaya</groupId>
<artifactId>tamaya-core</artifactId>
<version>…</version>
</dependency>
Core API & Implementation
<dependency>
<groupId>org.apache.tamaya.ext</groupId>
<artifactId>tamaya-spring</artifactId>
</dependency>
Basic Extensions Needed for Spring Support
<dependency>
<groupId>org.apache.tamaya.ext</groupId>
<artifactId>tamaya-functions</artifactId>
</dependency>
• Current version: 0.4-incubating-SNAPSHOT
• Tamaya only, for Microprofile also add Tamaya‘s
microprofile extension module
• Dont forget to use the Apache Snapshot Repo:
https://repository.apache.org/content/repositor
ies/snapshots

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2. Integrate with your target runtime

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3. Read/inject Configuration

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4. Add/write Configuration Backends (optional)
JSR 382/Microprofile Apache Tamaya
System Properties System Properties
Environment Properties Environment Properties
Classpath Resources Classpath Resources
CLI Args
Files, Resources, URLs
Etcd, consul
Hazelcast
OOTB Supported Configuration Backends:

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Recap!

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Recap: Configuration in Java
⚫ Configuration is a «hot» topic
⚫ JSR 382 stopped
⚫ Work will continue at Microprofile.io
⚫ Microprofile API is very puristic.
⚫ Apache Tamaya provides all features you will need and supports all major runtimes.
⚫ Apache Tamaya is ready to use!

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Links
• Tamaya Project Page: http://tamaya.incubator.apache.org
• Microprofile Project http://microprofile.io
• JSR 382 Infos: https://github.com/eclipse/configjsr
• Twitter: @microprofile, @ConfigJSR, @tamayaconfig
• Apache Deltaspike: http://deltaspike.apache.org
• Apache Commons Configuration: http://commons.apache.org/proper/commons-
configuration/
• Oracle Helidon: http://helidon.io

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Thank you!
Q&A
@atsticks
Anatole.tresch@trivadis.com

JSR 382 Configuration in Java Standards and More

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