added layout

logback-ecs-encoder/src/main/java/co/elastic/logging/logback/EcsEncoder.java

@@ -29,6 +29,7 @@
 import ch.qos.logback.classic.spi.ILoggingEvent;
 import ch.qos.logback.classic.spi.IThrowableProxy;
 import ch.qos.logback.classic.spi.ThrowableProxy;
+import ch.qos.logback.core.Layout;
 import ch.qos.logback.core.encoder.EncoderBase;
 import co.elastic.logging.AdditionalField;
 import co.elastic.logging.EcsJsonSerializer;
@@ -54,6 +55,7 @@ public class EcsEncoder extends EncoderBase<ILoggingEvent> {
     private boolean includeOrigin;
     private final List<AdditionalField> additionalFields = new ArrayList<AdditionalField>();
     private OutputStream os;
+    protected Layout<ILoggingEvent> layout;
 
     @Override
     public byte[] headerBytes() {
@@ -103,7 +105,7 @@ public byte[] encode(ILoggingEvent event) {
         StringBuilder builder = new StringBuilder(256);
         EcsJsonSerializer.serializeObjectStart(builder, event.getTimeStamp());
         EcsJsonSerializer.serializeLogLevel(builder, event.getLevel().toString());
-        EcsJsonSerializer.serializeFormattedMessage(builder, event.getFormattedMessage());
+        serializeMessage(event, builder);
         EcsJsonSerializer.serializeEcsVersion(builder);
         serializeMarkers(event, builder);
         EcsJsonSerializer.serializeServiceName(builder, serviceName);
@@ -136,6 +138,14 @@ public byte[] encode(ILoggingEvent event) {
         return builder.toString().getBytes(UTF_8);
     }
 
+    private void serializeMessage(ILoggingEvent event, StringBuilder builder) {
+        if(layout == null) {
+            EcsJsonSerializer.serializeFormattedMessage(builder, event.getFormattedMessage());
+        } else {
+            EcsJsonSerializer.serializeFormattedMessage(builder, this.layout.doLayout(event));
+        }
+    }
+
     /**
      * Subclasses can override this to add custom fields.
      * The last character in the StringBuilder will be comma when this is called.
@@ -198,4 +208,11 @@ public void setEventDataset(String eventDataset) {
     public void setThrowableConverter(ThrowableHandlingConverter throwableConverter) {
         this.throwableConverter = throwableConverter;
     }
+    public Layout<ILoggingEvent> getLayout() {
+        return this.layout;
+    }
+
+    public void setLayout(Layout<ILoggingEvent> layout) {
+        this.layout = layout;
+    }
 }