Fix logging in CloudFoundryVcapEnvironmentPostProcessor

See gh-19027

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/cloud/CloudFoundryVcapEnvironmentPostProcessor.java

@@ -22,14 +22,14 @@ import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.context.config.ConfigFileApplicationListener;
+import org.springframework.boot.context.event.ApplicationPreparedEvent;
 import org.springframework.boot.env.EnvironmentPostProcessor;
 import org.springframework.boot.json.JsonParser;
 import org.springframework.boot.json.JsonParserFactory;
+import org.springframework.boot.logging.DeferredLog;
+import org.springframework.context.ApplicationListener;
 import org.springframework.core.Ordered;
 import org.springframework.core.env.CommandLinePropertySource;
 import org.springframework.core.env.ConfigurableEnvironment;
@@ -89,9 +89,9 @@ import org.springframework.util.StringUtils;
  * @author Andy Wilkinson
  * @since 1.3.0
  */
-public class CloudFoundryVcapEnvironmentPostProcessor implements EnvironmentPostProcessor, Ordered {
+public class CloudFoundryVcapEnvironmentPostProcessor implements EnvironmentPostProcessor, Ordered, ApplicationListener<ApplicationPreparedEvent> {
 
-	private static final Log logger = LogFactory.getLog(CloudFoundryVcapEnvironmentPostProcessor.class);
+	private static final DeferredLog logger = new DeferredLog();
 
 	private static final String VCAP_APPLICATION = "VCAP_APPLICATION";
 
@@ -127,6 +127,11 @@ public class CloudFoundryVcapEnvironmentPostProcessor implements EnvironmentPost
 		}
 	}
 
+	@Override
+	public void onApplicationEvent(ApplicationPreparedEvent event) {
+		logger.switchTo(CloudFoundryVcapEnvironmentPostProcessor.class);
+	}
+
 	private void addWithPrefix(Properties properties, Properties other, String prefix) {
 		for (String key : other.stringPropertyNames()) {
 			String prefixed = prefix + key;

spring-boot-project/spring-boot/src/main/resources/META-INF/spring.factories

@@ -22,6 +22,7 @@ org.springframework.boot.web.context.ServerPortInfoApplicationContextInitializer
 org.springframework.context.ApplicationListener=\
 org.springframework.boot.ClearCachesApplicationListener,\
 org.springframework.boot.builder.ParentContextCloserApplicationListener,\
+org.springframework.boot.cloud.CloudFoundryVcapEnvironmentPostProcessor,\
 org.springframework.boot.context.FileEncodingApplicationListener,\
 org.springframework.boot.context.config.AnsiOutputApplicationListener,\
 org.springframework.boot.context.config.ConfigFileApplicationListener,\