Check log level before delegating Supplier-based message to target Log

Closes gh-25741

Author: jhoeller

spring-core/src/main/java/org/springframework/core/log/LogAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -225,7 +225,9 @@ public void trace(Throwable cause, CharSequence message) {
 	 * @param messageSupplier a lazy supplier for the message to log
 	 */
 	public void fatal(Supplier<? extends CharSequence> messageSupplier) {
-		this.log.fatal(LogMessage.of(messageSupplier));
+		if (this.log.isFatalEnabled()) {
+			this.log.fatal(LogMessage.of(messageSupplier));
+		}
 	}
 
 	/**
@@ -234,15 +236,19 @@ public void fatal(Supplier<? extends CharSequence> messageSupplier) {
 	 * @param messageSupplier a lazy supplier for the message to log
 	 */
 	public void fatal(Throwable cause, Supplier<? extends CharSequence> messageSupplier) {
-		this.log.fatal(LogMessage.of(messageSupplier), cause);
+		if (this.log.isFatalEnabled()) {
+			this.log.fatal(LogMessage.of(messageSupplier), cause);
+		}
 	}
 
 	/**
 	 * Log a message with error log level.
 	 * @param messageSupplier a lazy supplier for the message to log
 	 */
 	public void error(Supplier<? extends CharSequence> messageSupplier) {
-		this.log.error(LogMessage.of(messageSupplier));
+		if (this.log.isErrorEnabled()) {
+			this.log.error(LogMessage.of(messageSupplier));
+		}
 	}
 
 	/**
@@ -251,15 +257,19 @@ public void error(Supplier<? extends CharSequence> messageSupplier) {
 	 * @param messageSupplier a lazy supplier for the message to log
 	 */
 	public void error(Throwable cause, Supplier<? extends CharSequence> messageSupplier) {
-		this.log.error(LogMessage.of(messageSupplier), cause);
+		if (this.log.isErrorEnabled()) {
+			this.log.error(LogMessage.of(messageSupplier), cause);
+		}
 	}
 
 	/**
 	 * Log a message with warn log level.
 	 * @param messageSupplier a lazy supplier for the message to log
 	 */
 	public void warn(Supplier<? extends CharSequence> messageSupplier) {
-		this.log.warn(LogMessage.of(messageSupplier));
+		if (this.log.isWarnEnabled()) {
+			this.log.warn(LogMessage.of(messageSupplier));
+		}
 	}
 
 	/**
@@ -268,15 +278,19 @@ public void warn(Supplier<? extends CharSequence> messageSupplier) {
 	 * @param messageSupplier a lazy supplier for the message to log
 	 */
 	public void warn(Throwable cause, Supplier<? extends CharSequence> messageSupplier) {
-		this.log.warn(LogMessage.of(messageSupplier), cause);
+		if (this.log.isWarnEnabled()) {
+			this.log.warn(LogMessage.of(messageSupplier), cause);
+		}
 	}
 
 	/**
 	 * Log a message with info log level.
 	 * @param messageSupplier a lazy supplier for the message to log
 	 */
 	public void info(Supplier<? extends CharSequence> messageSupplier) {
-		this.log.info(LogMessage.of(messageSupplier));
+		if (this.log.isInfoEnabled()) {
+			this.log.info(LogMessage.of(messageSupplier));
+		}
 	}
 
 	/**
@@ -285,15 +299,19 @@ public void info(Supplier<? extends CharSequence> messageSupplier) {
 	 * @param messageSupplier a lazy supplier for the message to log
 	 */
 	public void info(Throwable cause, Supplier<? extends CharSequence> messageSupplier) {
-		this.log.info(LogMessage.of(messageSupplier), cause);
+		if (this.log.isInfoEnabled()) {
+			this.log.info(LogMessage.of(messageSupplier), cause);
+		}
 	}
 
 	/**
 	 * Log a message with debug log level.
 	 * @param messageSupplier a lazy supplier for the message to log
 	 */
 	public void debug(Supplier<? extends CharSequence> messageSupplier) {
-		this.log.debug(LogMessage.of(messageSupplier));
+		if (this.log.isDebugEnabled()) {
+			this.log.debug(LogMessage.of(messageSupplier));
+		}
 	}
 
 	/**
@@ -302,15 +320,19 @@ public void debug(Supplier<? extends CharSequence> messageSupplier) {
 	 * @param messageSupplier a lazy supplier for the message to log
 	 */
 	public void debug(Throwable cause, Supplier<? extends CharSequence> messageSupplier) {
-		this.log.debug(LogMessage.of(messageSupplier), cause);
+		if (this.log.isDebugEnabled()) {
+			this.log.debug(LogMessage.of(messageSupplier), cause);
+		}
 	}
 
 	/**
 	 * Log a message with trace log level.
 	 * @param messageSupplier a lazy supplier for the message to log
 	 */
 	public void trace(Supplier<? extends CharSequence> messageSupplier) {
-		this.log.trace(LogMessage.of(messageSupplier));
+		if (this.log.isTraceEnabled()) {
+			this.log.trace(LogMessage.of(messageSupplier));
+		}
 	}
 
 	/**
@@ -319,7 +341,9 @@ public void trace(Supplier<? extends CharSequence> messageSupplier) {
 	 * @param messageSupplier a lazy supplier for the message to log
 	 */
 	public void trace(Throwable cause, Supplier<? extends CharSequence> messageSupplier) {
-		this.log.trace(LogMessage.of(messageSupplier), cause);
+		if (this.log.isTraceEnabled()) {
+			this.log.trace(LogMessage.of(messageSupplier), cause);
+		}
 	}
 
 }