spring-jcl provides NoOpLog and SimpleLog as well

Issue: SPR-15957

Author: jhoeller

spring-jcl/src/main/java/org/apache/commons/logging/Log.java

@@ -22,8 +22,8 @@
  * instantiated successfully by {@link LogFactory}, classes that implement
  * this interface must have a constructor that takes a single String
  * parameter representing the "name" of this Log.
- * <p>
- * The six logging levels used by <code>Log</code> are (in order):
+ *
+ * <p>The six logging levels used by <code>Log</code> are (in order):
  * <ol>
  * <li>trace (the least serious)</li>
  * <li>debug</li>
@@ -32,185 +32,165 @@
  * <li>error</li>
  * <li>fatal (the most serious)</li>
  * </ol>
+ *
  * The mapping of these log levels to the concepts used by the underlying
  * logging system is implementation dependent.
  * The implementation should ensure, though, that this ordering behaves
  * as expected.
- * <p>
- * Performance is often a logging concern.
+ *
+ * <p>Performance is often a logging concern.
  * By examining the appropriate property,
  * a component can avoid expensive operations (producing information
  * to be logged).
- * <p>
- * For example,
+ *
+ * <p>For example,
  * <pre>
  *    if (log.isDebugEnabled()) {
  *        ... do something expensive ...
  *        log.debug(theResult);
  *    }
  * </pre>
- * <p>
- * Configuration of the underlying logging system will generally be done
+ *
+ * <p>Configuration of the underlying logging system will generally be done
  * external to the Logging APIs, through whatever mechanism is supported by
  * that system.
  *
- * @version $Id: Log.java 1606045 2014-06-27 12:11:56Z tn $
+ * @author Juergen Hoeller (for the {@code spring-jcl} variant)
+ * @since 5.0
  */
 public interface Log {
 
-    /**
-     * Logs a message with debug log level.
-     *
-     * @param message log this message
-     */
-    void debug(Object message);
-
-    /**
-     * Logs an error with debug log level.
-     *
-     * @param message log this message
-     * @param t log this cause
-     */
-    void debug(Object message, Throwable t);
-
-    /**
+	/**
+	 * Is fatal logging currently enabled?
+	 * <p>Call this method to prevent having to perform expensive operations
+	 * (for example, <code>String</code> concatenation)
+	 * when the log level is more than fatal.
+	 * @return true if fatal is enabled in the underlying logger.
+	 */
+	boolean isFatalEnabled();
+
+	/**
+	 * Is error logging currently enabled?
+	 * <p>Call this method to prevent having to perform expensive operations
+	 * (for example, <code>String</code> concatenation)
+	 * when the log level is more than error.
+	 * @return true if error is enabled in the underlying logger.
+	 */
+	boolean isErrorEnabled();
+
+	/**
+	 * Is warn logging currently enabled?
+	 * <p>Call this method to prevent having to perform expensive operations
+	 * (for example, <code>String</code> concatenation)
+	 * when the log level is more than warn.
+	 * @return true if warn is enabled in the underlying logger.
+	 */
+	boolean isWarnEnabled();
+
+	/**
+	 * Is info logging currently enabled?
+	 * <p>Call this method to prevent having to perform expensive operations
+	 * (for example, <code>String</code> concatenation)
+	 * when the log level is more than info.
+	 * @return true if info is enabled in the underlying logger.
+	 */
+	boolean isInfoEnabled();
+
+	/**
+	 * Is debug logging currently enabled?
+	 * <p>Call this method to prevent having to perform expensive operations
+	 * (for example, <code>String</code> concatenation)
+	 * when the log level is more than debug.
+	 * @return true if debug is enabled in the underlying logger.
+	 */
+	boolean isDebugEnabled();
+
+	/**
+	 * Is trace logging currently enabled?
+	 * <p>Call this method to prevent having to perform expensive operations
+	 * (for example, <code>String</code> concatenation)
+	 * when the log level is more than trace.
+	 * @return true if trace is enabled in the underlying logger.
+	 */
+	boolean isTraceEnabled();
+
+
+	/**
+	 * Logs a message with fatal log level.
+	 * @param message log this message
+	 */
+	void fatal(Object message);
+
+	/**
+	 * Logs an error with fatal log level.
+	 * @param message log this message
+	 * @param t log this cause
+	 */
+	void fatal(Object message, Throwable t);
+
+	/**
      * Logs a message with error log level.
-     *
      * @param message log this message
      */
     void error(Object message);
 
     /**
      * Logs an error with error log level.
-     *
      * @param message log this message
      * @param t log this cause
      */
     void error(Object message, Throwable t);
 
-    /**
-     * Logs a message with fatal log level.
-     *
-     * @param message log this message
-     */
-    void fatal(Object message);
+	/**
+	 * Logs a message with warn log level.
+	 * @param message log this message
+	 */
+	void warn(Object message);
 
-    /**
-     * Logs an error with fatal log level.
-     *
-     * @param message log this message
-     * @param t log this cause
-     */
-    void fatal(Object message, Throwable t);
+	/**
+	 * Logs an error with warn log level.
+	 * @param message log this message
+	 * @param t log this cause
+	 */
+	void warn(Object message, Throwable t);
 
     /**
      * Logs a message with info log level.
-     *
      * @param message log this message
      */
     void info(Object message);
 
     /**
      * Logs an error with info log level.
-     *
      * @param message log this message
      * @param t log this cause
      */
     void info(Object message, Throwable t);
 
-    /**
-     * Is debug logging currently enabled?
-     * <p>
-     * Call this method to prevent having to perform expensive operations
-     * (for example, <code>String</code> concatenation)
-     * when the log level is more than debug.
-     *
-     * @return true if debug is enabled in the underlying logger.
-     */
-    boolean isDebugEnabled();
+	/**
+	 * Logs a message with debug log level.
+	 * @param message log this message
+	 */
+	void debug(Object message);
 
-    /**
-     * Is error logging currently enabled?
-     * <p>
-     * Call this method to prevent having to perform expensive operations
-     * (for example, <code>String</code> concatenation)
-     * when the log level is more than error.
-     *
-     * @return true if error is enabled in the underlying logger.
-     */
-    boolean isErrorEnabled();
-
-    /**
-     * Is fatal logging currently enabled?
-     * <p>
-     * Call this method to prevent having to perform expensive operations
-     * (for example, <code>String</code> concatenation)
-     * when the log level is more than fatal.
-     *
-     * @return true if fatal is enabled in the underlying logger.
-     */
-    boolean isFatalEnabled();
-
-    /**
-     * Is info logging currently enabled?
-     * <p>
-     * Call this method to prevent having to perform expensive operations
-     * (for example, <code>String</code> concatenation)
-     * when the log level is more than info.
-     *
-     * @return true if info is enabled in the underlying logger.
-     */
-    boolean isInfoEnabled();
-
-    /**
-     * Is trace logging currently enabled?
-     * <p>
-     * Call this method to prevent having to perform expensive operations
-     * (for example, <code>String</code> concatenation)
-     * when the log level is more than trace.
-     *
-     * @return true if trace is enabled in the underlying logger.
-     */
-    boolean isTraceEnabled();
+	/**
+	 * Logs an error with debug log level.
+	 * @param message log this message
+	 * @param t log this cause
+	 */
+	void debug(Object message, Throwable t);
 
-    /**
-     * Is warn logging currently enabled?
-     * <p>
-     * Call this method to prevent having to perform expensive operations
-     * (for example, <code>String</code> concatenation)
-     * when the log level is more than warn.
-     *
-     * @return true if warn is enabled in the underlying logger.
-     */
-    boolean isWarnEnabled();
-
-    /**
+	/**
      * Logs a message with trace log level.
-     *
      * @param message log this message
      */
     void trace(Object message);
 
     /**
      * Logs an error with trace log level.
-     *
      * @param message log this message
      * @param t log this cause
      */
     void trace(Object message, Throwable t);
 
-    /**
-     * Logs a message with warn log level.
-     *
-     * @param message log this message
-     */
-    void warn(Object message);
-
-    /**
-     * Logs an error with warn log level.
-     *
-     * @param message log this message
-     * @param t log this cause
-     */
-    void warn(Object message, Throwable t);
 }

spring-jcl/src/main/java/org/apache/commons/logging/LogFactory.java

@@ -57,7 +57,7 @@
  * (or another SLF4J provider) onto your classpath, without any extra bridges,
  * and let the framework auto-adapt to your choice.
  *
- * @author Juergen Hoeller
+ * @author Juergen Hoeller (for the {@code spring-jcl} variant)
  * @since 5.0
  */
 public abstract class LogFactory {