java-configuration

Simple environment-based configuration for Java.

Usage

Import to Project

<dependency>
    <groupId>com.msiops.garage</groupId>
    <artifactId>garage-configuration</artifactId>
    <version>${v.configuration}</version>
</dependency>

See Maven Central for latest version

Load Properties

// environment name is in sysprop "garage.environment"
// default environment is "development"

// properties loaded from resource, "{environment}.properties"
// in class's package.
final Properties props = Configuration.of(MyClass.class);

// with defaults
final Properties props = Configuration.of(MyClass.class, defProps);

Override Properties

final Properties props = ...
final Collection<String> overrides = Arrays.asList("sys.prop", "sys.other.prop");

// any matching system properties override
final Properties overridden = Configuration.override(props, overrides);


final Properties addl = ...
// any matching properties from source override
final Properties overridden2 = Configuration.override(props, overrides, addl);


final Map<String,String> spec = Collections.singletonMap("USER", "my.app.user");
// env USER value is added to props as "my.app.user"
final Properties overridden2 = Configuration.overrideFromEnv(props, spec);

Detach

Properties p = new Properties();
p.setProperty("key","value");

Properties detached = Configuration.detach(p);
p.setProperty("key","changed");
assert detached.getProperty("key").equals("value");

Partial Properties Map

Properties p = new Properties();
p.setProperty("base.a", "avalue");
p.setProperty("base.b", "bvalue");

Map<String,String> partial = Configuration.asMap(p, "base");
assert partial.get("a").equals("avalue");
assert partial.get("b").equals("bvalue");

Versioning

Releases in the 0.x series are the Wild West. Anything can change between releases--package names, method signatures, behavior, whatever. But if you like it as it is right now, all the tests pass so just use it at its current version and have fun.

The next version series will be 1.x. Every release in that series will be backward compatible with every lower-numbered release in the same series except possibly in the case of 1) a bug fix or 2) a correction to an underspecification.

An incompatible change to the interface, behavior, license, or anything else after the 1.x series is published will result in a new series, such as 2.x.

Acknowledgements

This module attempts to simplify environment-based configuration as prescribed in Continuous Delivery by Humble and Farley.

Thanks to Media Science International for its support of FOSS.

License

Licensed to Media Science International (MSI) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. MSI licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.