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commit c846b21dcbf9c98d2a96526c3be253a038e3a79e
Author: Volkan Yazıcı <volkan.yaz...@gmail.com>
AuthorDate: Fri Jun 19 10:24:08 2020 +0200
#335 Add fallbackKey to MessageResolver.
---
.../json/template/resolver/MessageResolver.java | 116 +++++++++++++--------
.../json/template/JsonTemplateLayoutTest.java | 50 +++++++++
src/site/asciidoc/manual/json-template-layout.adoc | 23 +++-
3 files changed, 142 insertions(+), 47 deletions(-)
diff --git
a/log4j-layout-json-template/src/main/java/org/apache/logging/log4j/layout/json/template/resolver/MessageResolver.java
b/log4j-layout-json-template/src/main/java/org/apache/logging/log4j/layout/json/template/resolver/MessageResolver.java
index 54daefe..53dc7d9 100644
---
a/log4j-layout-json-template/src/main/java/org/apache/logging/log4j/layout/json/template/resolver/MessageResolver.java
+++
b/log4j-layout-json-template/src/main/java/org/apache/logging/log4j/layout/json/template/resolver/MessageResolver.java
@@ -18,6 +18,7 @@ package
org.apache.logging.log4j.layout.json.template.resolver;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.layout.json.template.util.JsonWriter;
+import org.apache.logging.log4j.message.MapMessage;
import org.apache.logging.log4j.message.Message;
import org.apache.logging.log4j.message.MultiformatMessage;
import org.apache.logging.log4j.message.ObjectMessage;
@@ -30,8 +31,9 @@ import org.apache.logging.log4j.util.StringBuilderFormattable;
* <h3>Configuration</h3>
*
* <pre>
- * config = [ stringified ]
+ * config = [ stringified ] , [ fallbackKey ]
* stringified = "stringified" -> boolean
+ * fallbackKey = "fallbackKey" -> string
* </pre>
*
* <h3>Examples</h3>
@@ -54,6 +56,28 @@ import
org.apache.logging.log4j.util.StringBuilderFormattable;
* "$resolver": "message"
* }
* </pre>
+ *
+ * Given the above configuration, a {@link SimpleMessage} will generate a
+ * <tt>"sample log message"</tt>, whereas a {@link MapMessage} will generate a
+ * <tt>{"action": "login", "sessionId": "87asd97a"}</tt>. Certain indexed log
+ * storage systems (e.g., <a
+ * href="https://www.elastic.co/elasticsearch/";>Elasticsearch</a>) will not
+ * allow both values to coexist due to type mismatch: one is a <tt>string</tt>
+ * while the other is an <tt>object</tt>. Here one can use a
+ * <tt>fallbackKey</tt> to work around the problem:
+ *
+ * <pre>
+ * {
+ * "$resolver": "message",
+ * "fallbackKey": "formattedMessage"
+ * }
+ * </pre>
+ *
+ * Using this configuration, a {@link SimpleMessage} will generate a
+ * <tt>{"formattedMessage": "sample log message"}</tt> and a {@link MapMessage}
+ * will generate a <tt>{"action": "login", "sessionId": "87asd97a"}</tt>. Note
+ * that both emitted JSONs are of type <tt>object</tt> and have no
+ * type-conflicting fields.
*/
final class MessageResolver implements EventResolver {
@@ -72,9 +96,14 @@ final class MessageResolver implements EventResolver {
private static EventResolver createInternalResolver(
final TemplateResolverConfig config) {
final boolean stringified = config.getBoolean("stringified", false);
+ final String fallbackKey = config.getString("fallbackKey");
+ if (stringified && fallbackKey != null) {
+ throw new IllegalArgumentException(
+ "fallbackKey is not allowed when stringified is enable: "
+ config);
+ }
return stringified
- ? MessageResolver::resolveString
- : MessageResolver::resolveObject;
+ ? createStringResolver(fallbackKey)
+ : createObjectResolver(fallbackKey);
}
@Override
@@ -84,16 +113,27 @@ final class MessageResolver implements EventResolver {
internalResolver.resolve(logEvent, jsonWriter);
}
+ private static EventResolver createStringResolver(final String
fallbackKey) {
+ return (final LogEvent logEvent, final JsonWriter jsonWriter) ->
+ resolveString(fallbackKey, logEvent, jsonWriter);
+ }
+
private static void resolveString(
+ final String fallbackKey,
final LogEvent logEvent,
final JsonWriter jsonWriter) {
final Message message = logEvent.getMessage();
- resolveString(message, jsonWriter);
+ resolveString(fallbackKey, message, jsonWriter);
}
private static void resolveString(
+ final String fallbackKey,
final Message message,
final JsonWriter jsonWriter) {
+ if (fallbackKey != null) {
+ jsonWriter.writeObjectStart();
+ jsonWriter.writeObjectKey(fallbackKey);
+ }
if (message instanceof StringBuilderFormattable) {
final StringBuilderFormattable formattable =
(StringBuilderFormattable) message;
@@ -102,48 +142,35 @@ final class MessageResolver implements EventResolver {
final String formattedMessage = message.getFormattedMessage();
jsonWriter.writeString(formattedMessage);
}
- }
-
- private static void resolveObject(
- final LogEvent logEvent,
- final JsonWriter jsonWriter) {
-
- // Try SimpleMessage serializer.
- final Message message = logEvent.getMessage();
- if (writeSimpleMessage(jsonWriter, message)) {
- return;
- }
-
- // Try MultiformatMessage serializer.
- if (writeMultiformatMessage(jsonWriter, message)) {
- return;
+ if (fallbackKey != null) {
+ jsonWriter.writeObjectEnd();
}
+ }
- // Try ObjectMessage serializer.
- if (writeObjectMessage(jsonWriter, message)) {
- return;
- }
+ private static EventResolver createObjectResolver(final String
fallbackKey) {
+ return (final LogEvent logEvent, final JsonWriter jsonWriter) -> {
- // Fallback to plain Object write.
- resolveString(logEvent, jsonWriter);
+ // Skip custom serializers for SimpleMessage.
+ final Message message = logEvent.getMessage();
+ final boolean simple = message instanceof SimpleMessage;
+ if (!simple) {
- }
+ // Try MultiformatMessage serializer.
+ if (writeMultiformatMessage(jsonWriter, message)) {
+ return;
+ }
- private static boolean writeSimpleMessage(
- final JsonWriter jsonWriter,
- final Message message) {
+ // Try ObjectMessage serializer.
+ if (writeObjectMessage(jsonWriter, message)) {
+ return;
+ }
- // Check type.
- if (!(message instanceof SimpleMessage)) {
- return false;
- }
- final SimpleMessage simpleMessage = (SimpleMessage) message;
+ }
- // Write message.
- final String formattedMessage = simpleMessage.getFormattedMessage();
- jsonWriter.writeString(formattedMessage);
- return true;
+ // Fallback to plain String serializer.
+ resolveString(fallbackKey, logEvent, jsonWriter);
+ };
}
private static boolean writeMultiformatMessage(
@@ -165,16 +192,13 @@ final class MessageResolver implements EventResolver {
break;
}
}
-
- // Write the formatted JSON, if supported.
- if (jsonSupported) {
- final String messageJson =
multiformatMessage.getFormattedMessage(FORMATS);
- jsonWriter.writeRawString(messageJson);
- return true;
+ if (!jsonSupported) {
+ return false;
}
- // Fallback to the default message formatter.
- resolveString((LogEvent) message, jsonWriter);
+ // Write the formatted JSON.
+ final String messageJson =
multiformatMessage.getFormattedMessage(FORMATS);
+ jsonWriter.writeRawString(messageJson);
return true;
}
diff --git
a/log4j-layout-json-template/src/test/java/org/apache/logging/log4j/layout/json/template/JsonTemplateLayoutTest.java
b/log4j-layout-json-template/src/test/java/org/apache/logging/log4j/layout/json/template/JsonTemplateLayoutTest.java
index 38ef58f..4419b58 100644
---
a/log4j-layout-json-template/src/test/java/org/apache/logging/log4j/layout/json/template/JsonTemplateLayoutTest.java
+++
b/log4j-layout-json-template/src/test/java/org/apache/logging/log4j/layout/json/template/JsonTemplateLayoutTest.java
@@ -38,6 +38,7 @@ import
org.apache.logging.log4j.layout.json.template.JsonTemplateLayout.EventTem
import org.apache.logging.log4j.layout.json.template.util.JsonReader;
import org.apache.logging.log4j.layout.json.template.util.JsonWriter;
import org.apache.logging.log4j.layout.json.template.util.MapAccessor;
+import org.apache.logging.log4j.message.Message;
import org.apache.logging.log4j.message.ObjectMessage;
import org.apache.logging.log4j.message.SimpleMessage;
import org.apache.logging.log4j.message.StringMapMessage;
@@ -321,6 +322,55 @@ public class JsonTemplateLayoutTest {
}
@Test
+ public void test_message_fallbackKey() {
+
+ // Create the event template.
+ final String eventTemplate = writeJson(Map(
+ "message", Map(
+ "$resolver", "message",
+ "fallbackKey", "formattedMessage")));
+
+ // Create the layout.
+ final JsonTemplateLayout layout = JsonTemplateLayout
+ .newBuilder()
+ .setConfiguration(CONFIGURATION)
+ .setEventTemplate(eventTemplate)
+ .build();
+
+ // Create a log event with a MapMessage.
+ final Message mapMessage = new StringMapMessage()
+ .with("key1", "val1");
+ final LogEvent mapMessageLogEvent = Log4jLogEvent
+ .newBuilder()
+ .setLoggerName(LOGGER_NAME)
+ .setLevel(Level.INFO)
+ .setMessage(mapMessage)
+ .setTimeMillis(System.currentTimeMillis())
+ .build();
+
+ // Check the serialized MapMessage.
+ usingSerializedLogEventAccessor(layout, mapMessageLogEvent, accessor ->
+ assertThat(accessor.getString(new String[]{"message", "key1"}))
+ .isEqualTo("val1"));
+
+ // Create a log event with a SimpleMessage.
+ final Message simpleMessage = new SimpleMessage("simple");
+ final LogEvent simpleMessageLogEvent = Log4jLogEvent
+ .newBuilder()
+ .setLoggerName(LOGGER_NAME)
+ .setLevel(Level.INFO)
+ .setMessage(simpleMessage)
+ .setTimeMillis(System.currentTimeMillis())
+ .build();
+
+ // Check the serialized MapMessage.
+ usingSerializedLogEventAccessor(layout, simpleMessageLogEvent,
accessor ->
+ assertThat(accessor.getString(new String[]{"message",
"formattedMessage"}))
+ .isEqualTo("simple"));
+
+ }
+
+ @Test
public void test_property_injection() {
// Create the log event.
diff --git a/src/site/asciidoc/manual/json-template-layout.adoc
b/src/site/asciidoc/manual/json-template-layout.adoc
index f3e22db..9b819d1 100644
--- a/src/site/asciidoc/manual/json-template-layout.adoc
+++ b/src/site/asciidoc/manual/json-template-layout.adoc
@@ -733,8 +733,9 @@ parent such that keys are prefixed with `_`:
a|
[source]
----
-config = [ stringified ]
+config = [ stringified ] , [ fallbackKey ]
stringified = "stringified" -> boolean
+fallbackKey = "fallbackKey" -> string
----
a| `logEvent.getMessage()`
| For simple string messages, the resolution is performed without allocations.
@@ -761,6 +762,26 @@ will be retained:
}
----
+Given the above configuration, a `SimpleMessage` will generate a `"sample log
+message"`, whereas a `MapMessage` will generate a `{"action": "login",
+"sessionId": "87asd97a"}`. Certain indexed log storage systems (e.g.,
+https://www.elastic.co/elasticsearch/[Elasticsearch]) will not allow both
values
+to coexist due to type mismatch: one is a `string` while the other is an
`object`.
+Here one can use a `fallbackKey` to work around the problem:
+
+[source,json]
+----
+{
+ "$resolver": "message",
+ "fallbackKey": "formattedMessage"
+}
+----
+
+Using this configuration, a `SimpleMessage` will generate a
+`{"formattedMessage": "sample log message"}` and a `MapMessage` will generate a
+`{"action": "login", "sessionId": "87asd97a"}`. Note that both emitted JSONs
are
+of type `object` and have no type-conflicting fields.
+
| ndc
a|
[source]
