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 boolean	getBoolean(Class<?> type, String name, boolean defValue)	Retrieves a boolean setting
static Charset	getCharset(Class<?> type, String name, Charset defValue)	Retrieves a Charset setting
static double	getDouble(Class<?> type, String name, double defValue)	Retrieves a double setting
static Duration	getDuration(Class<?> type, String name, 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 InetSocketAddress	getInetSocketAddress(Class<?> type, String name, InetSocketAddress defValue)	Retrieves a InetSocketAddress setting
static int	getInt(Class<?> type, String name, int defValue)	Retrieves an int setting
static Locale	getLocale(Class<?> type, String name, Locale defValue)	Retrieves a Locale setting
static long	getLong(Class<?> type, String name, long defValue)	Retrieves a long setting
static MemSize	getMemSize(Class<?> type, String name, MemSize defValue)	Retrieves a MemSize setting
static String	getString(Class<?> type, String name, String defValue)	Retrieves a String setting
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

public static <T> T get(Function<String,T> parser,
 Class<?> type,
 String name,
 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

public static String getString(Class<?> type,
 String name,
 String defValue)

Retrieves a String setting

See Also:

• get(Function, Class, String, Object)

getInt

public static int getInt(Class<?> type,
 String name,
 int defValue)

Retrieves an int setting

See Also:

• get(Function, Class, String, Object)

getLong

public static long getLong(Class<?> type,
 String name,
 long defValue)

Retrieves a long setting

See Also:

• get(Function, Class, String, Object)

getBoolean

public static boolean getBoolean(Class<?> type,
 String name,
 boolean defValue)

Retrieves a boolean setting

See Also:

• get(Function, Class, String, Object)

getDouble

public static double getDouble(Class<?> type,
 String name,
 double defValue)

Retrieves a double setting

See Also:

• get(Function, Class, String, Object)

getDuration

public static Duration getDuration(Class<?> type,
 String name,
 Duration defValue)

Retrieves a Duration setting

See Also:

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

getMemSize

public static MemSize getMemSize(Class<?> type,
 String name,
 MemSize defValue)

Retrieves a MemSize setting

See Also:

• get(Function, Class, String, Object)

getInetSocketAddress

public static InetSocketAddress getInetSocketAddress(Class<?> type,
 String name,
 InetSocketAddress defValue)

Retrieves a InetSocketAddress setting

See Also:

• get(Function, Class, String, Object)

getCharset

public static Charset getCharset(Class<?> type,
 String name,
 Charset defValue)

Retrieves a Charset setting

See Also:

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

getLocale

public static Locale getLocale(Class<?> type,
 String name,
 Locale defValue)

Retrieves a Locale setting

See Also:

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

getEnum

public static <E extends Enum<E>> E getEnum(Class<?> type,
 String name,
 Class<E> enumClass,
 E defValue)

Retrieves a Enum setting

See Also:

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