Package io.activej.common

Class ApplicationSettings

java.lang.Object

io.activej.common.ApplicationSettings

public final class ApplicationSettings
extends Object

A class for initializing runtime constants

Each application setting provides a name of a class, a name of a setting, and a default value to be used in case a setting is not explicitly set

A setting is searched by using both fully qualified class name and a class's simple name

By default, system properties are searched to find whether a setting is explicitly set. However, alternative properties may be used as a source. Individual settings may also be set programmatically.

After any setting has been looked up it is not allowed to change properties source or update individual settings. Hence, all configuration should preferably happen in a static initialization block before constants have been initialized.

Constructor Summary

Constructors

Constructor	Description
ApplicationSettings()

Method Summary

Modifier and Type	Method	Description
static <T> T	get(Function<String,T> parser, Class<?> type, String name, T defValue)	Retrieves a setting.
static @Nullable Boolean	getBoolean(Class<?> type, String name, Boolean defValue)	Retrieves a boolean setting
static @Nullable Charset	getCharset(Class<?> type, String name, @Nullable Charset defValue)	Retrieves a Charset setting
static @Nullable Double	getDouble(Class<?> type, String name, Double defValue)	Retrieves a double setting
static @Nullable Duration	getDuration(Class<?> type, String name, @Nullable Duration defValue)	Retrieves a Duration setting
static <E extends Enum<E>> E	getEnum(Class<?> type, String name, Class<E> enumClass, E defValue)	Retrieves a Enum setting
static @Nullable InetSocketAddress	getInetSocketAddress(Class<?> type, String name, @Nullable InetSocketAddress defValue)	Retrieves a InetSocketAddress setting
static @Nullable Integer	getInt(Class<?> type, String name, Integer defValue)	Retrieves an int setting
static @Nullable Locale	getLocale(Class<?> type, String name, @Nullable Locale defValue)	Retrieves a Locale setting
static @Nullable Long	getLong(Class<?> type, String name, Long defValue)	Retrieves a long setting
static @Nullable MemSize	getMemSize(Class<?> type, String name, @Nullable MemSize defValue)	Retrieves a MemSize setting
static @Nullable String	getString(Class<?> type, String name, @Nullable String defValue)	Retrieves a String setting
static boolean	parseBoolean(String s)
static void	set(Class<?> type, String name, Object value)	Sets a custom setting
static void	useProperties(Properties properties)	Uses alternative properties to look up settings

Methods inherited from class java.lang.Object

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

Constructor Details

ApplicationSettings

public ApplicationSettings()

Method Details

useProperties

public static void useProperties(Properties properties)

Uses alternative properties to look up settings

This method should not be called after any setting look up has been made

Parameters:

properties - alternative properties

set

public static void set(Class<?> type,
 String name,
 Object value)

Sets a custom setting

This setting will override settings from properties

This method should not be called after any setting look up has been made

Parameters:

type - a class referenced by a setting

name - a name of a setting

value - a value of a setting

get

@Contract("_, _, _, !null -> !null")
@Nullable
public static <T> T get(Function<String,T> parser,
 Class<?> type,
 String name,
 @Nullable
 T defValue)

Retrieves a setting. This is a base method that can be used to parse a setting string into an arbitrary value.

A setting is searched by using both fully qualified class name and a class's simple name

Parameters:

parser - function that transforms a setting string into a value

type - a class referenced by a setting

name - a name of a setting

defValue - default value that will be used if a setting property is not found

getString

@Contract("_, _, !null -> !null")
@Nullable
public static @Nullable String getString(Class<?> type,
 String name,
 @Nullable
 @Nullable String defValue)

Retrieves a String setting

See Also:

• get(Function, Class, String, Object)

getInt

@Contract("_, _, !null -> !null")
@Nullable
public static @Nullable Integer getInt(Class<?> type,
 String name,
 Integer defValue)

Retrieves an int setting

See Also:

• get(Function, Class, String, Object)

getLong

@Contract("_, _, !null -> !null")
@Nullable
public static @Nullable Long getLong(Class<?> type,
 String name,
 Long defValue)

Retrieves a long setting

See Also:

• get(Function, Class, String, Object)

getBoolean

@Contract("_, _, !null -> !null")
@Nullable
public static @Nullable Boolean getBoolean(Class<?> type,
 String name,
 Boolean defValue)

Retrieves a boolean setting

See Also:

• get(Function, Class, String, Object)

parseBoolean

public static boolean parseBoolean(String s)

getDouble

@Contract("_, _, !null -> !null")
@Nullable
public static @Nullable Double getDouble(Class<?> type,
 String name,
 Double defValue)

Retrieves a double setting

See Also:

• get(Function, Class, String, Object)

getDuration

@Contract("_, _, !null -> !null")
@Nullable
public static @Nullable Duration getDuration(Class<?> type,
 String name,
 @Nullable
 @Nullable Duration defValue)

Retrieves a Duration setting

See Also:

• get(Function, Class, String, Object)
• Duration.parse(CharSequence)

getMemSize

@Contract("_, _, !null -> !null")
@Nullable
public static @Nullable MemSize getMemSize(Class<?> type,
 String name,
 @Nullable
 @Nullable MemSize defValue)

Retrieves a MemSize setting

See Also:

• get(Function, Class, String, Object)

getInetSocketAddress

@Contract("_, _, !null -> !null")
@Nullable
public static @Nullable InetSocketAddress getInetSocketAddress(Class<?> type,
 String name,
 @Nullable
 @Nullable InetSocketAddress defValue)

Retrieves a InetSocketAddress setting

See Also:

• get(Function, Class, String, Object)

getCharset

@Contract("_, _, !null -> !null")
@Nullable
public static @Nullable Charset getCharset(Class<?> type,
 String name,
 @Nullable
 @Nullable Charset defValue)

Retrieves a Charset setting

See Also:

• get(Function, Class, String, Object)
• Charset.forName(String)

getLocale

@Contract("_, _, !null -> !null")
@Nullable
public static @Nullable Locale getLocale(Class<?> type,
 String name,
 @Nullable
 @Nullable Locale defValue)

Retrieves a Locale setting

See Also:

• get(Function, Class, String, Object)
• Locale.forLanguageTag(String)

getEnum

@Contract("_, _, _, !null -> !null")
@Nullable
public static <E extends Enum<E>> E getEnum(Class<?> type,
 String name,
 Class<E> enumClass,
 @Nullable
 E defValue)

Retrieves a Enum setting

See Also:

• get(Function, Class, String, Object)
• Enum.valueOf(Class, String)