com.databricks.jdbc.log.JdbcLoggerFactory Maven / Gradle / Ivy
package com.databricks.jdbc.log;
import java.util.Map;
import java.util.Optional;
import java.util.concurrent.ConcurrentHashMap;
/**
* Factory class for creating JDBC logger instances. This class supports creating loggers based on
* the specified logger implementation. The logger implementation can be specified through a system
* property {@value #LOGGER_IMPL_PROPERTY}. Supported logger implementations include SLF4J and JDK
* logging.
*/
public class JdbcLoggerFactory {
public static final String LOGGER_IMPL_PROPERTY = "com.databricks.jdbc.loggerImpl";
/** Holds the singleton instance of the logger implementation determined at runtime. */
private static volatile LoggerImpl loggerImpl;
/** A map of logger implementation names to their corresponding {@link LoggerImpl} enum values. */
private static final Map LOGGER_IMPL_MAP = new ConcurrentHashMap<>();
static {
for (LoggerImpl impl : LoggerImpl.values()) {
LOGGER_IMPL_MAP.put(impl.getLoggerImplClassName().toLowerCase(), impl);
}
}
/** Private constructor to prevent instantiation. */
private JdbcLoggerFactory() {
throw new AssertionError("JdbcLoggerFactory is not instantiable.");
}
/** Enum representing the supported logger implementations. */
enum LoggerImpl {
SLF4JLOGGER("SLF4JLOGGER"),
JDKLOGGER("JDKLOGGER");
private final String loggerImplClassName;
LoggerImpl(String loggerClass) {
this.loggerImplClassName = loggerClass;
}
public String getLoggerImplClassName() {
return loggerImplClassName;
}
/**
* Returns an {@link Optional} containing the {@link LoggerImpl} corresponding to the given
* logger implementation class name, if it exists.
*/
public static Optional fromString(String loggerImplClassName) {
return Optional.ofNullable(loggerImplClassName)
.map(String::toLowerCase)
.map(LOGGER_IMPL_MAP::get);
}
}
/** Returns a {@link JdbcLogger} instance for the specified class. */
public static JdbcLogger getLogger(Class clazz) {
resolveLoggerImpl();
switch (loggerImpl) {
case JDKLOGGER:
return new JulLogger(clazz.getName());
case SLF4JLOGGER:
default:
return new Slf4jLogger(clazz);
}
}
/** Returns a {@link JdbcLogger} instance for the specified name. */
public static JdbcLogger getLogger(String name) {
resolveLoggerImpl();
switch (loggerImpl) {
case JDKLOGGER:
return new JulLogger(name);
case SLF4JLOGGER:
default:
return new Slf4jLogger(name);
}
}
/**
* Resolves the logger implementation to be used. This method checks the system property {@value
* #LOGGER_IMPL_PROPERTY} to determine the logger implementation. If the property is not set, it
* defaults to {@link LoggerImpl#SLF4JLOGGER}.
*/
private static void resolveLoggerImpl() {
if (loggerImpl == null) {
synchronized (JdbcLoggerFactory.class) {
if (loggerImpl == null) {
String logger = System.getProperty(LOGGER_IMPL_PROPERTY);
loggerImpl = LoggerImpl.fromString(logger).orElse(LoggerImpl.JDKLOGGER);
}
}
}
}
}