org.apache.tamaya.optional

Class OptionalConfiguration

java.lang.Object

org.apache.tamaya.optional.OptionalConfiguration

public final class OptionalConfiguration
extends Object

Simplified configuration API, that can be used by code that only wants Tamaya to optionally enhance its configuration mechanism, but by default uses its own configuration by default.

Field Summary

Fields

Modifier and Type	Field and Description
static ValueProvider	DEFAULT_PROVIDER Default value provider returning Strings from system properties and the system environment.
static ValueProvider	NULLPROVIDER Default value provider that always returns null.

Method Summary

Methods

Modifier and Type	Method and Description
String	get(String key) Access a String value.
<T> T	get(String key, Class<T> type) Method that returns the corresponding value, depending on the availability of Tamaya, the registered provider and evaluation policy.
<T> T	getOrDefault(String key, Class<T> type, T defaultValue) Access a String value.
String	getOrDefault(String key, String defaultValue) Access a String value.
static OptionalConfiguration	of(EvaluationPolicy policy) Returns a default instance, which uses a default provider returning values from system properties and environment only.
static OptionalConfiguration	of(EvaluationPolicy policy, ValueProvider provider) Returns an instance of OptionalConfiguration, which uses the given provider and policy for evaluating the values.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_PROVIDER

public static final ValueProvider DEFAULT_PROVIDER

Default value provider returning Strings from system properties and the system environment. In all other cases null is returned.

NULLPROVIDER

public static final ValueProvider NULLPROVIDER

Default value provider that always returns null.

Method Detail

of

public static OptionalConfiguration of(EvaluationPolicy policy,
                       ValueProvider provider)

Returns an instance of OptionalConfiguration, which uses the given provider and policy for evaluating the values.

Parameters:

policy - the policy how a value should be evaluated depending if Tamaya is available or not.

provider - the non Tamaya-based provider to be used to evaluate values.

Returns:

a default OptionalConfiguration instance, never null.

of

public static OptionalConfiguration of(EvaluationPolicy policy)

Returns a default instance, which uses a default provider returning values from system properties and environment only.

Parameters:

policy - the policy how a value should be evaluated depending if Tamaya is available or not.

Returns:

a default OptionalConfiguration instance, never null.

get

public String get(String key)

Access a String value.

Parameters:

key - the key, not null.

Returns:

the value found, or null.

getOrDefault

public String getOrDefault(String key,
                  String defaultValue)

Access a String value.

Parameters:

key - the key, not null.

defaultValue - the default value, returned if no such key is found in the configuration.

Returns:

the value found, or null.

get

public <T> T get(String key,
        Class<T> type)

Method that returns the corresponding value, depending on the availability of Tamaya, the registered provider and evaluation policy.

Type Parameters:

T - the type param.

Parameters:

key - the key, not null.

type - the target type, not null.

Returns:

the value, or null.

getOrDefault

public <T> T getOrDefault(String key,
                 Class<T> type,
                 T defaultValue)

Access a String value.

Type Parameters:

T - the type param.

Parameters:

key - the key, not null.

type - the target type, not null.

defaultValue - the default value, returned if no such key is found in the configuration.

Returns:

the value found, or null.