Polish

See gh-3684

spring-boot/src/main/java/org/springframework/boot/logging/LoggingApplicationListener.java

@@ -192,13 +192,18 @@ public class LoggingApplicationListener implements GenericApplicationListener {
 		}
 		if (System.getProperty(EXCEPTION_CONVERSION_WORD) == null) {
 			System.setProperty(EXCEPTION_CONVERSION_WORD,
-					environment.getProperty("logging.exception-conversion-word", "%rEx"));
+					getExceptionConversionWord(environment));
 		}
 		initializeEarlyLoggingLevel(environment);
 		initializeSystem(environment, this.loggingSystem);
 		initializeFinalLoggingLevels(environment, this.loggingSystem);
 	}
 
+	private String getExceptionConversionWord(ConfigurableEnvironment environment) {
+		RelaxedPropertyResolver resolver = new RelaxedPropertyResolver(environment, "logging.");
+		return resolver.getProperty("exception-conversion-word", "%rEx");
+	}
+
 	private void initializeEarlyLoggingLevel(ConfigurableEnvironment environment) {
 		if (this.parseArgs && this.springBootLogging == null) {
 			if (environment.containsProperty("debug")) {

spring-boot/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -29,6 +29,13 @@
     "description": "Location of the logging configuration file.",
     "sourceType": "org.springframework.boot.logging.LoggingApplicationListener"
   },
+  {
+    "name": "logging.exception-conversion-word",
+    "type": "java.lang.String",
+    "description": "Conversion word used when logging exceptions.",
+    "defaultValue": "%rEx",
+    "sourceType": "org.springframework.boot.logging.LoggingApplicationListener"
+  },
   {
     "name": "logging.file",
     "type": "java.lang.String",

spring-boot/src/test/java/org/springframework/boot/logging/LoggingApplicationListenerTests.java

@@ -332,7 +332,7 @@ public class LoggingApplicationListenerTests {
 	@Test
 	public void overrideExceptionConversionWord() throws Exception {
 		EnvironmentTestUtils.addEnvironment(this.context,
-				"logging.exception-conversion-word:%ex");
+				"logging.exceptionConversionWord:%ex");
 		this.initializer.initialize(this.context.getEnvironment(),
 				this.context.getClassLoader());
 		this.outputCapture.expect(containsString("Hello world"));