ru.vyarus.dropwizard.guice.module.context.option.mapper

Class OptionsMapper

java.lang.Object

ru.vyarus.dropwizard.guice.module.context.option.mapper.OptionsMapper

public class OptionsMapper
extends java.lang.Object

Helper utility class for mapping options from system properties, environment variables or direct string. Used with GuiceBundle.Builder.options(Map). May recognize multiple prefixed options from properties (see props(String)).

Only existing properties are mapped. If value is null or property is not defined - it's ignored.

Example usage:

     builder.options(new OptionsMapper()
                              .env("ENV_PROP", MyOptions.Opt1)
                              .env("ENV_PROP_CUST", MyOptions.Opt2, val -> convertVal(val))
                              .prop("sys.prop", MyOptions.Opt3)
                              .string(MyOptions.Opt4, "value")
                              .map())

 

Only string, boolean, integer, double, short. byte enum by value, enum by class, array and EnumSet option types are directly supported (see StringConverter). For other types explicit converters must be used.

To enable generic options definition from properties use:

  .options(new OptionsMapper().props().map())
 

This will map system properties prefixed with "option." and with full enum class and value. For example, -Doption.ru.vyarus.dropwizard.guice.GuiceyOptions.InjectorStage=DEVELOPMENT.

In order to apply special conversion for some property (when default converters can't properly convert value) declare manual property binding before mass processing:

 .options(new OptionsMapper()
            .prop("option.ru.vyarus.dropwizard.guice.GuiceyOptions.InjectorStage", GuiceyOptions.InjectorStage,
                 val -> someConversion(val))
            .props()
            .map())
 

And option will be ignored during mass processing (because it's processed manually).

To see actual assignments (for debug) use printMappings().

Since:

26.04.2018

Constructor Summary

Constructors

Constructor and Description
OptionsMapper()

Method Summary

Modifier and Type	Method and Description
<T extends java.lang.Enum & Option> OptionsMapper	env(java.lang.String name, T option) Shortcut version of env(String, Enum, Function).
<V,T extends java.lang.Enum & Option> OptionsMapper	env(java.lang.String name, T option, java.util.function.Function<java.lang.String,V> converter) Map environment variable value to option.
java.util.Map<java.lang.Enum,java.lang.Object>	map()
OptionsMapper	printMappings() Enable assignment logging (to system out, as loggers are not yet initialized).
<T extends java.lang.Enum & Option> OptionsMapper	prop(java.lang.String name, T option) Shortcut version of prop(String, Enum, Function).
<V,T extends java.lang.Enum & Option> OptionsMapper	prop(java.lang.String name, T option, java.util.function.Function<java.lang.String,V> converter) Directly map system property value to option.
OptionsMapper	props() Shortcut for props(String) with "option." prefix.
<T extends java.lang.Enum & Option> OptionsMapper	props(java.lang.String prefix) Search for system properties, prefixed with provided string.
<V,T extends java.lang.Enum & Option> OptionsMapper	string(T option, java.lang.String value) Shortcut version of string(Enum, String, Function).
<V,T extends java.lang.Enum & Option> OptionsMapper	string(T option, java.lang.String value, java.util.function.Function<java.lang.String,V> converter) Map string to option.

Methods inherited from class java.lang.Object

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

Constructor Detail

OptionsMapper

public OptionsMapper()

Method Detail

printMappings

public OptionsMapper printMappings()

Enable assignment logging (to system out, as loggers are not yet initialized).

Returns:

mapper instance for chained calls

props

public OptionsMapper props()

Shortcut for props(String) with "option." prefix.

Returns:

mapper instance for chained calls

props

public <T extends java.lang.Enum & Option> OptionsMapper props(java.lang.String prefix)

Search for system properties, prefixed with provided string. Property format must be: "(prefix)enumClassName.enumValue". For example: option.ru.vyarus.dropwizard.guice.GuiceyOptions.UseHkBridge where "option." is prefix.

Could be used only for string, boolean, integer, double, short and byte option types.

If some options require special handling then map them directly using prop(String, Enum, Function) and only AFTER that call mass processing.

Type Parameters:

T - helper option type

Parameters:

prefix - options prefix

Returns:

mapper instance for chained calls

prop

public <T extends java.lang.Enum & Option> OptionsMapper prop(java.lang.String name,
                                                              T option)

Shortcut version of prop(String, Enum, Function). Used when default converters could be used.

Type Parameters:

T - helper option type

Parameters:

name - property name

option - option

Returns:

mapper instance for chained calls

prop

public <V,T extends java.lang.Enum & Option> OptionsMapper prop(java.lang.String name,
                                                                T option,
                                                                java.util.function.Function<java.lang.String,V> converter)

Directly map system property value to option.

Directly mapped properties excluded from mass processing in props(String), but direct mapping must appear before mass-processing.

Type Parameters:

T - helper option type

V - value type

Parameters:

name - property name

option - option

converter - value converter (may be null to use default converters)

Returns:

mapper instance for chained calls

env

public <T extends java.lang.Enum & Option> OptionsMapper env(java.lang.String name,
                                                             T option)

Shortcut version of env(String, Enum, Function). Used when default converters could be used.

Type Parameters:

T - helper option type

Parameters:

name - environment variable name

option - option

Returns:

mapper instance for chained calls

env

public <V,T extends java.lang.Enum & Option> OptionsMapper env(java.lang.String name,
                                                               T option,
                                                               java.util.function.Function<java.lang.String,V> converter)

Map environment variable value to option.

Type Parameters:

V - helper value type

T - helper option type

Parameters:

name - environment variable name

option - option

converter - value converter (may be null to use default converters)

Returns:

mapper instance for chained calls

string

public <V,T extends java.lang.Enum & Option> OptionsMapper string(T option,
                                                                  java.lang.String value)

Shortcut version of string(Enum, String, Function). Used when default converters could be used.

Type Parameters:

V - helper value type

T - helper option type

Parameters:

option - option

value - value string (could be null)

Returns:

mapper instance for chained calls

string

public <V,T extends java.lang.Enum & Option> OptionsMapper string(T option,
                                                                  java.lang.String value,
                                                                  java.util.function.Function<java.lang.String,V> converter)

Map string to option. When value is null or empty - nothing happens.

Type Parameters:

V - helper value type

T - helper option type

Parameters:

option - option

value - value string (could be null)

converter - value converter (may be null to use default converters)

Returns:

mapper instance for chained calls

map

public java.util.Map<java.lang.Enum,java.lang.Object> map()

Returns:

map of resolved options