Polish

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/system/ApplicationPidListener.java

@@ -26,13 +26,12 @@ import org.springframework.boot.context.event.ApplicationStartedEvent;
 import org.springframework.context.ApplicationListener;
 import org.springframework.core.Ordered;
 import org.springframework.util.Assert;
-import org.springframework.util.SystemPropertyUtils;
 
 /**
  * An {@link org.springframework.context.ApplicationListener} that saves application PID
- * into file. This application listener will be triggered exactly once per JVM, and the file
- * name can be overridden at runtime with a System property or environment variable named
- * "PIDFILE" (or "pidfile").
+ * into file. This application listener will be triggered exactly once per JVM, and the
+ * file name can be overridden at runtime with a System property or environment variable
+ * named "PIDFILE" (or "pidfile").
  *
  * @author Jakub Kubrynski
  * @author Dave Syer
@@ -46,6 +45,8 @@ public class ApplicationPidListener implements
 
 	private static final String DEFAULT_FILE_NAME = "application.pid";
 
+	private static final String[] PROPERTY_VARIABLES = { "PIDFILE", "pidfile" };
+
 	private static final AtomicBoolean created = new AtomicBoolean(false);
 
 	private int order = Ordered.HIGHEST_PRECEDENCE + 13;
@@ -74,10 +75,30 @@ public class ApplicationPidListener implements
 	 */
 	public ApplicationPidListener(File file) {
 		Assert.notNull(file, "File must not be null");
-		String actual = SystemPropertyUtils.resolvePlaceholders("${PIDFILE}", true);
-		actual = !actual.contains("$") ? actual :  SystemPropertyUtils.resolvePlaceholders("${pidfile}", true);
-		actual = !actual.contains("$") ? actual :  file.getAbsolutePath();
-		this.file = new File(actual);
+		String override = getOverride();
+		if (override != null) {
+			this.file = new File(override);
+		}
+		else {
+			this.file = file;
+		}
+	}
+
+	private String getOverride() {
+		for (String property : PROPERTY_VARIABLES) {
+			try {
+				String override = System.getProperty(property);
+				override = (override != null ? override : System.getenv(property));
+				if (override != null) {
+					return override;
+				}
+			}
+			catch (Throwable ex) {
+				System.err.println("Could not resolve '" + property
+						+ "' as system property: " + ex);
+			}
+		}
+		return null;
 	}
 
 	@Override

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/system/ApplicationPidListenerTests.java

@@ -67,7 +67,9 @@ public class ApplicationPidListenerTests {
 		System.setProperty("PIDFILE", this.temporaryFolder.newFile().getAbsolutePath());
 		ApplicationPidListener listener = new ApplicationPidListener(file);
 		listener.onApplicationEvent(EVENT);
-		assertThat(FileCopyUtils.copyToString(new FileReader(System.getProperty("PIDFILE"))), not(isEmptyString()));
+		assertThat(
+				FileCopyUtils.copyToString(new FileReader(System.getProperty("PIDFILE"))),
+				not(isEmptyString()));
 	}
 
 }

spring-boot-docs/src/main/asciidoc/howto.adoc

@@ -465,11 +465,11 @@ HTTPS connector:
 
 [[howto-use-tomcat-behind-a-proxy-server]]
 === Use Tomcat behind a front-end proxy server
-Spring Boot will automatically configure Tomcat's `RemoteIpValve` if you enable it. This allows you to
-transparently use the standard `x-forwarded-for` and `x-forwarded-proto` headers that
-most front-end proxy servers add. The valve is switched on by setting one or both of these
-properties to something non-empty (these are the conventional values used by most proxies, and if
-you only set one the other will be set automatically):
+Spring Boot will automatically configure Tomcat's `RemoteIpValve` if you enable it. This
+allows you to transparently use the standard `x-forwarded-for` and `x-forwarded-proto`
+headers that most front-end proxy servers add. The valve is switched on by setting one or
+both of these properties to something non-empty (these are the conventional values used by
+most proxies, and if you only set one the other will be set automatically):
 
 [indent=0]
 ----
@@ -477,9 +477,8 @@ you only set one the other will be set automatically):
 	server.tomcat.protocol_header=x-forwarded-protocol
 ----
 
-If your proxy uses different headers you can
-customize the valve's configuration by adding some entries to `application.properties`,
-e.g.
+If your proxy uses different headers you can customize the valve's configuration by adding
+some entries to `application.properties`, e.g.
 
 [indent=0]
 ----