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AndHow! strong.valid.simple.AppConfiguration

Strongly typed configuration with detailed validation that is simple to use for web apps, command line or any application environment.

Features

• Strong Typing. Configuration Propertys are typed and only return that type. The getValue() method of the StrProp (String Property) returns a String. The getValue() method of an IntProp (Integer Property) returns an Integer.
• Detailed validation. Each Property can be required or optional. Strings can be matched to regex, bounds applied to numbers, etc..
• Load property values from nearly any property source, including property files, JNDI, command line, environmental variables and system properties.
• Simple construction via builders.
• Simple initial configuration via auto-generated sample files.
• Use configuration Properties in code just like Java constants, e.g.: MY_CONFIG_PROPERTY.getValue(); This eliminates a problematic aspect of most configuration strategies, which require value keys buried in your source code, e.g.: hashMap.get("HiddenMagicKey");
• Fail-Fast. Type conversion and validation are applied at startup, rather than at use.
• Managed session. A single application configuration initiation point is enforced. Race conditions or missing initiation fails rather than returning null for properties.
• Consolidated and structured application configuration API. Configuration Properties include a type, description, and validation rules. Properties can be grouped into logical sets with descriptions. Libraries/modules can present their entire configuration API as a PropertyGroup.
• Extensible value types and configuration sources. New types and sources of configuration (such as from a db) can be easily added.
• Clear error messages. Because Properties include metadata like name, description, type and validation rules, detailed error messages can be constructed.
• Support for legacy applications using System Properties. Normally AndHow provides its own names for properties, however, it is also possible to use aliases. An in alias provides a short name to read from a source, such as a property file or from command line. An out alias provides an alternate name used to export the property. A GroupExport annotation on a PropertyGroup will direct AndHow to export property value to some other form - Currently exporting to SystemProperties is the only option supported, but that covers a lot of legacy code.