Package migratedb.v1.core.api.logging

Class LogSystems

java.lang.Object

migratedb.v1.core.api.logging.LogSystems

public final class LogSystems
extends Object

Pre-defined log system names and auto-detection.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	APACHE_COMMONS	org.apache.commons.logging system.
static final String	AUTO_DETECT	Auto-detect based on environment.
static final String	CONSOLE	An alias that means the fallback logger will be used (this library has no opinion on what a "console" log should be).
static final String	JAVA_UTIL	java.util.logging system.
static final String	NONE	Suppresses all log messages.
static final String	SLF4J	org.slf4j system.

Constructor Summary

Constructors

Constructor	Description
LogSystems()

Method Summary

Modifier and Type	Method	Description
static LogSystem	autoDetect(ClassLoader classLoader, @Nullable LogSystem fallback)	Auto-detects the "best" available log system and returns an instance of it.
static LogSystem	custom(String className, ClassLoader classLoader)	Instantiates a class that implements LogSystem.
static LogSystem	fromStrings(Set<String> logSystemNames, ClassLoader classLoader, @Nullable LogSystem fallback)	Creates a log system that forwards logging calls to all log system names in logSystemNames.

Methods inherited from class java.lang.Object

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

Field Details

APACHE_COMMONS

public static final String APACHE_COMMONS

org.apache.commons.logging system.

See Also:

• Constant Field Values

AUTO_DETECT

public static final String AUTO_DETECT

Auto-detect based on environment. See autoDetect(ClassLoader, LogSystem).

See Also:

• Constant Field Values

JAVA_UTIL

public static final String JAVA_UTIL

java.util.logging system.

See Also:

• Constant Field Values

SLF4J

public static final String SLF4J

org.slf4j system.

See Also:

• Constant Field Values

CONSOLE

public static final String CONSOLE

An alias that means the fallback logger will be used (this library has no opinion on what a "console" log should be).

See Also:

• Constant Field Values

NONE

public static final String NONE

Suppresses all log messages.

See Also:

• Constant Field Values

Constructor Details

LogSystems

public LogSystems()

Method Details

fromStrings

public static LogSystem fromStrings(Set<String> logSystemNames,
 ClassLoader classLoader,
 @Nullable LogSystem fallback)

Creates a log system that forwards logging calls to all log system names in logSystemNames. Each log system name must either be one of the string constants in this class or the fully qualified name of a class that implements LogSystem and has a public no-arg constructor.

Parameters:

logSystemNames - The log system names to parse

classLoader - Used to instantiate classes by name

fallback - Used for AUTO_DETECT and CONSOLE (the latter being a direct alias for it)

Returns:

Log system that delegates to all log systems identified by logSystemNames.

custom

public static LogSystem custom(String className,
 ClassLoader classLoader)

Instantiates a class that implements LogSystem.

Parameters:

className - Fully qualified name of class to instantiate. Class must have a public no-arg constructor.

classLoader - Class loader to use.

Returns:

The custom log system.

autoDetect

public static LogSystem autoDetect(ClassLoader classLoader,
 @Nullable LogSystem fallback)

Auto-detects the "best" available log system and returns an instance of it. The order of precedence is:

1. If one of the supported logging libraries is found via classLoader, use it.
2. If fallback is non-null, use that.
3. Use java.util.logging.

Parameters:

classLoader - Used to check for the presence of supported logging libraries.

fallback - Log system to use over java.util.logging

Returns:

Auto-detected log system.