io.stargate.config.store.api

Class ConfigWithOverrides

java.lang.Object

io.stargate.config.store.api.ConfigWithOverrides

public class ConfigWithOverrides
extends Object

Constructor Summary

Constructors

Constructor and Description
ConfigWithOverrides(Map<String,Object> configMap, String moduleName)

Method Summary

Modifier and Type	Method and Description
Map<String,Object>	getConfigMap() It returns the underlying config-map without any override applied.
<T> Optional<T>	getOptionalSettingValue(String settingName, Class<T> expectedType) It retrieves the value wrapped in the Optional from underlying configMap checking for its type.
<T> T	getSettingValue(String settingName, Class<T> expectedType) It retrieves the value from underlying configMap checking for its presence and type.
<T> List<T>	getSettingValueList(String settingName, Class<T> expectedType) It retrieves the list of values from underlying configMap checking for its presence and the type.
String	getWithOverrides(String settingName) This is a convenience method that calls the this#getWithOverrides(String, Function) with a String.valueOf(Object) mapper function.
String	getWithOverrides(String settingName, Function<Object,String> objectToStringMapper) It returns a specific setting value for settingName.

Methods inherited from class java.lang.Object

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

Constructor Detail

ConfigWithOverrides

public ConfigWithOverrides(@Nonnull
                           Map<String,Object> configMap,
                           @Nonnull
                           String moduleName)

Method Detail

getConfigMap

public Map<String,Object> getConfigMap()

It returns the underlying config-map without any override applied. If you want to get a specific value with override, please use the this#getWithOverrides(String, Function) or this#getWithOverrides(String, Function) method.

getSettingValueList

@Nonnull
public <T> List<T> getSettingValueList(@Nonnull
                                                String settingName,
                                                @Nonnull
                                                Class<T> expectedType)

It retrieves the list of values from underlying configMap checking for its presence and the type. If the value for a given settingName does not have a value, it throws an IllegalArgumentException. If the type of the setting value is not a List it throws IllegalArgumentException. If the underlying type of any element in this list does not match the expectedType, it throws IllegalArgumentException.

Parameters:

settingName - - it will be used as a key of underlying configMap.

expectedType - - it will be used to check if the type of an actual list element value matches.

Returns:

the list of values associated with settingName. Each value matches expectedType.

getSettingValue

@Nonnull
public <T> T getSettingValue(@Nonnull
                                      String settingName,
                                      @Nonnull
                                      Class<T> expectedType)

It retrieves the value from underlying configMap checking for its presence and type. If the value for a given settingName does not have a value, it throws an IllegalArgumentException. If the type of the setting value does not match the expectedType, it throws IllegalArgumentException.

Parameters:

settingName - - it will be used as a key of underlying configMap.

expectedType - - it will be used to check if the type of an actual setting value matches.

Returns:

the value associated with settingName, matching expectedType.

getOptionalSettingValue

@Nonnull
public <T> Optional<T> getOptionalSettingValue(@Nonnull
                                                        String settingName,
                                                        @Nonnull
                                                        Class<T> expectedType)

It retrieves the value wrapped in the Optional from underlying configMap checking for its type. If the value for a given settingName does not have a value, it returns Optional.empty() If the type of the setting value does not match the expectedType, it throws IllegalArgumentException.

Parameters:

settingName - - it will be used as a key of underlying configMap.

expectedType - - it will be used to check if the type of an actual setting value matches.

Returns:

the value wrapped in the Optional associated with settingName, matching expectedType.

getWithOverrides

@Nullable
public String getWithOverrides(@Nonnull
                                         String settingName,
                                         @Nonnull
                                         Function<Object,String> objectToStringMapper)

It returns a specific setting value for settingName.

It looks for a setting value in the following order:

1. Java System property (System.getProperty()

2. OS environment variable

3. Underlying config map

When trying to retrieve the system property and environment variable, it will use the full setting name. It will add the module name for which this `ConfigWithOverrides` is created.

For example, if the String moduleName = "m_1" and you are calling this getWithOverrides() method for settingName = "s" it will firstly try to System.getProperty("m_1.s"), then System.getenv("m_1.s") and finally get the config from the underlying map using Map.get("s").

Prefixing with module name is done to avoid conflicts of overrides between modules.

Please keep in mind that if you are overriding settings via a System property or OS environment variable, it will be a String value. If the underlying config map does contain a value of non String type, and the override is not provided, the objectToStringMapper function will be called. This function is transforming the object into a String type, and you can provide a custom for this transformation. If the underlying configMap does not contain a value for the given settingName, the objectToStringMapper is not called, so you don't need to handle nulls.

Returns:

the value with the highest priority or null if there is no value associated with the given settingName.

getWithOverrides

@Nullable
public String getWithOverrides(@Nonnull
                                         String settingName)

This is a convenience method that calls the this#getWithOverrides(String, Function) with a String.valueOf(Object) mapper function.