org.apache.jackrabbit.oak.commons.properties

Class SystemPropertySupplier<T>

java.lang.Object

org.apache.jackrabbit.oak.commons.properties.SystemPropertySupplier<T>

All Implemented Interfaces:

java.util.function.Supplier<T>

public class SystemPropertySupplier<T>
extends java.lang.Object
implements java.util.function.Supplier<T>

Utility class for consistent handling of system properties.

It provides for:

• TRACE level logging of getting the system property
• ERROR level logging when value does not parse or is invalid (where validity can be checked by a Predicate)
• (default) INFO level logging when value differs from default (log level and message format can be overridden)

The supported types are: Boolean, Integer, Long, String

Method Summary

Modifier and Type	Method and Description
static <U> SystemPropertySupplier<U>	create(@NotNull java.lang.String propName, U defaultValue) Create it for a given property name and default value.
SystemPropertySupplier<T>	formatSetMessage(@NotNull java.util.function.BiFunction<java.lang.String,T,java.lang.String> setMessageFormatter) Specify a formatter for the "success" log message to be used when the returned property value differs from the default.
T	get() Obtains the value of a system property, optionally generating diagnostics.
SystemPropertySupplier<T>	loggingTo(@NotNull org.slf4j.Logger log) Specify the Logger to log to (defaults to this classes logger otherwise).
SystemPropertySupplier<T>	logSuccessAs(org.slf4j.event.Level successLogLevel) Specify Level to use for "success" message.
protected SystemPropertySupplier<T>	usingSystemPropertyReader(@NotNull java.util.function.Function<java.lang.String,java.lang.String> sysPropReader) For unit testing: specify a function to read system properties (overriding default of System.getProperty(String).
SystemPropertySupplier<T>	validateWith(@NotNull java.util.function.Predicate<T> validator) Specify a validation expression.

Methods inherited from class java.lang.Object

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

Method Detail

create

public static <U> SystemPropertySupplier<U> create(@NotNull
                                                   @NotNull java.lang.String propName,
                                                   @NotNull
                                                   U defaultValue)
                                            throws java.lang.IllegalArgumentException

Create it for a given property name and default value.

Throws:

java.lang.IllegalArgumentException

loggingTo

public SystemPropertySupplier<T> loggingTo(@NotNull
                                           @NotNull org.slf4j.Logger log)

Specify the Logger to log to (defaults to this classes logger otherwise).

validateWith

public SystemPropertySupplier<T> validateWith(@NotNull
                                              @NotNull java.util.function.Predicate<T> validator)

Specify a validation expression.

formatSetMessage

public SystemPropertySupplier<T> formatSetMessage(@NotNull
                                                  @NotNull java.util.function.BiFunction<java.lang.String,T,java.lang.String> setMessageFormatter)

Specify a formatter for the "success" log message to be used when the returned property value differs from the default.

logSuccessAs

public SystemPropertySupplier<T> logSuccessAs(org.slf4j.event.Level successLogLevel)

Specify Level to use for "success" message.

usingSystemPropertyReader

protected SystemPropertySupplier<T> usingSystemPropertyReader(@NotNull
                                                              @NotNull java.util.function.Function<java.lang.String,java.lang.String> sysPropReader)

For unit testing: specify a function to read system properties (overriding default of System.getProperty(String).

get

public T get()

Obtains the value of a system property, optionally generating diagnostics.

Specified by:

get in interface java.util.function.Supplier<T>

Returns:

value of system property