Streamable interface for SAX-style message rendering

Author: Michael Edwards

layout/src/main/java/com/vlkan/log4j2/logstash/layout/resolver/MessageResolver.java

@@ -2,6 +2,7 @@
 
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.core.JsonGenerator;
+import com.vlkan.log4j2.logstash.layout.util.Streamable;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.logging.log4j.core.LogEvent;
 import org.apache.logging.log4j.message.Message;
@@ -54,6 +55,10 @@ private String resolveText(Message message) {
     }
 
     private void resolveJson(Message message, JsonGenerator jsonGenerator) throws IOException {
+        if (message instanceof Streamable) {
+            ((Streamable) message).streamTo(jsonGenerator);
+            return;
+        }
 
         // Check message type.
         if (!(message instanceof MultiformatMessage)) {

layout/src/main/java/com/vlkan/log4j2/logstash/layout/util/Streamable.java

@@ -0,0 +1,8 @@
+package com.vlkan.log4j2.logstash.layout.util;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import java.io.IOException;
+
+public interface Streamable {
+    public abstract void streamTo(JsonGenerator stream) throws IOException;
+}