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

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	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 Logger log)`	Specify the `Logger` to log to (defaults to this classes logger otherwise).
`SystemPropertySupplier<T>`	`logSuccessAs(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 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(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

Class SystemPropertySupplier<T>