Log API Improvements #974

mrodbratschi · 2025-06-05T17:41:04Z

Issue:204872
Add custom JSON logging support with unescaped data and plain message fields

Ensured data field is unescaped JSON, while message remains a simple String
Updated EcsLayout.json to include message, data, and context fields (or add a new template)
context is populated via MDC (ThreadContext.put) and supports simple key-value pairs

…age` fields - Ensured `data` field is unescaped JSON, while `message` remains a simple String - Updated `EcsLayout.json` to include `message`, `data`, and `context` fields (or add a new template) - `context` is populated via MDC (`ThreadContext.put`) and supports simple key-value pairs

…to be compatible with the existing implementation of the log (the old implementation remains unchanged).

…hod isEnabled

…abs/JavaClasses into feature/log-improvement

…hods

iroqueta · 2025-06-26T21:34:34Z

common/src/main/java/com/genexus/diagnostics/core/ILogger.java

+
+	default boolean isEnabled(int logLevel) { return false; }
+
+	//boolean isEnabled(int logLevel, String topic);


Why is this method commented?

Fix: Remove unnecessary comment

iroqueta · 2025-06-26T21:35:47Z

common/src/main/java/com/genexus/diagnostics/UserLog.java

+	}
+
+	public static void write(String message, String topic, int logLevel, Object data) {
+		getLogger(topic).write(message, logLevel, data, false);


I think it's better to call write(message, logLevel, data, false); here to avoid duplicating code.

Fix: Avoid code duplication

iroqueta · 2025-06-26T21:37:57Z

wrappercommon/pom.xml

+		</dependency>
+        <dependency>
+            <groupId>com.google.code.gson</groupId>
+            <artifactId>gson</artifactId>


We're already using a JSON handling library (org.json), so I'd consider whether we can use that instead of Gson to avoid having two separate libraries for JSON processing.

We're already using a JSON handling library (org.json), so I'd consider whether we can use that instead of Gson to avoid having two separate libraries for JSON processing.

I did an implementation using org.json, the problems I found with this library are these:

It doesn't keep the order of the inserted element in the JSON (It uses internally a HashMap instead of LinkedHashMap).

The code is more complex than using Gson.

The order of the elements is my main concern, do you think it is not relevant for an end user? For example, to print the parameters of a function, or print SDTs, etc., they will be out of order after serialization.

The order of elements in a JSON object is not relevant according to the JSON specification

The order of elements in a JSON object is not relevant according to the JSON specification

Ok, this is the implementation using org.json: Uses org.json instead of Gson

iroqueta · 2025-06-26T21:54:07Z

wrappercommon/src/main/java/com/genexus/diagnostics/core/provider/Log4J2Logger.java

+		Map<String, Object> mapMessage = new LinkedHashMap<>();
+
+		if (data == null || (data instanceof String && "null".equals(data.toString()))) {
+			mapMessage.put(dataKey, (Object) null);


this cast is not necessary

It is fixed when I migrate to org.json, in this commit: Uses org.json instead of Gson

iroqueta · 2025-06-26T21:55:57Z

wrappercommon/src/main/java/com/genexus/diagnostics/core/provider/Log4J2Logger.java

+
+		for (Appender appender : config.getAppenders().values()) {
+			if (appender instanceof AbstractAppender) {
+				Object layout = ((AbstractAppender) appender).getLayout();


this cast is not necessary

Fix: Remove casting

iroqueta · 2025-06-26T21:58:29Z

wrappercommon/src/main/java/com/genexus/diagnostics/core/provider/CustomEcsLayout.json

@@ -0,0 +1,57 @@
+{


I can't understand this template when exactly is it loaded to be used?

It is loaded here: PR #959
Fix: Move it to the resources folder. When compiling it will be in the root of the jar

iroqueta

I left some comments.

tomas-sexenian · 2025-06-26T16:20:46Z

common/src/main/java/com/genexus/diagnostics/LogLevel.java

@@ -2,13 +2,12 @@

 public class LogLevel {


Can we do something like this? To ensure type safety

public enum LogLevel { OFF(0), TRACE(1), DEBUG(5), INFO(10), WARNING(15), ERROR(20), FATAL(30); private final int lvl; LogLevel(int lvl) { this.lvl = lvl; } public int intValue() { return lvl; } }

We need a function like this inside that enum, to be able to assign the value of the received log level.
public static LogLevel fromInt(int lvl) { for (LogLevel level : LogLevel.values()) { if (level.intValue() == lvl) { return level; } } return LogLevel.OFF; }

Fix: Ensure type safety

tomas-sexenian · 2025-06-26T16:22:11Z

common/src/main/java/com/genexus/diagnostics/UserLog.java

+		return getLogger().isInfoEnabled();
+	}
+
+	public static boolean isWarnEnabled() {


Your level constant is called WARNING, but the method is isWarnEnabled(). It’s better if the naming matches exactly (e.g. either rename the constant to WARN or the method to isWarningEnabled())

Fix: Rename constant to WARN

tomas-sexenian · 2025-06-26T16:27:39Z

wrappercommon/src/main/java/com/genexus/diagnostics/core/provider/CustomMessageFactory.java

+
+@Plugin(name = "CustomMessageFactory", category = TemplateResolverFactory.CATEGORY)
+public final class CustomMessageFactory implements EventResolverFactory {
+	private static final CustomMessageFactory INSTANCE = new CustomMessageFactory();


Right now you have a package-private default constructor (implicit), plus a single INSTANCE. It’s clearer to readers if you explicitly prevent instantiation

private static final CustomMessageFactory INSTANCE = new CustomMessageFactory(); private CustomMessageFactory() { /* no instances */ }

Fix: Explicitly prevent instantiation

tomas-sexenian · 2025-06-26T16:30:25Z

wrappercommon/src/main/java/com/genexus/diagnostics/core/provider/CustomMessageFactory.java

+import org.apache.logging.log4j.layout.template.json.resolver.TemplateResolverFactory;
+
+
+@Plugin(name = "CustomMessageFactory", category = TemplateResolverFactory.CATEGORY)


Not 100% sure about this one but right now the plugin is called "CustomMessageFactory", but your resolver class is CustomMessageResolver. It can be confusing in XML/JSON layouts if you have to write:
<CustomMessageFactory …/>
Maybe renaming the plugin to "CustomMessage" (or "CustomMessageResolver") so it reads naturally in config and maps 1:1 to your resolver’s functionality.

I followed the example in the official documentation, I don't know what the CustomMessageFactory string is for.
Anyway I have made the change as you say.

Fix: Plugin rename

tomas-sexenian · 2025-06-26T16:33:27Z

wrappercommon/src/main/java/com/genexus/diagnostics/core/provider/Log4J2Logger.java

+
+	private static final String STACKTRACE_KEY = "stackTrace";
+	private static final String MESSAGE_KEY = "message";
+


You currently always build your JSON or text payload—even if that level is disabled—only to have Log4j drop it. To avoid the cost of JSON parsing/serialization on disabled levels, add at the top of your write(...)

Fix: Build the message only if the loglevel is enabled

tomas-sexenian · 2025-06-26T16:35:11Z

wrappercommon/src/main/java/com/genexus/diagnostics/core/provider/Log4J2Logger.java

+	private static final String STACKTRACE_KEY = "stackTrace";
+	private static final String MESSAGE_KEY = "message";
+
+	private void writeTextFormat(String message, int logLevel, Object data, boolean stackTrace) {


Right now every write() walks the entire configuration looking for a JsonTemplateLayout. That’s very expensive if you’re logging hundreds of messages per second. Instead:

Compute it once (e.g. in your constructor, or lazily in a volatile Boolean isJsonLayout field).

Reuse that flag on each write.

Fix: Check if the log format is JSON once.

tomas-sexenian · 2025-06-26T16:35:55Z

wrappercommon/src/main/java/com/genexus/diagnostics/core/provider/Log4J2Logger.java

+			mapMessage.put(STACKTRACE_KEY, getStackTraceAsList());
+		}
+
+		String json = new Gson().newBuilder().serializeNulls().create().toJson(mapMessage);


You call new Gson().newBuilder().serializeNulls().create() on every text‐format write.
Instead:

private static final Gson GSON = new GsonBuilder().serializeNulls().create();

And then reuse GSON.toJson(...). This avoids constant object churn.

It was fixed when I migrated to org.json instead of Gson: Uses org.json instead of Gson

tomas-sexenian · 2025-06-26T16:37:37Z

wrappercommon/src/main/java/com/genexus/diagnostics/core/provider/Log4J2Logger.java

+
+	private static List<String> getStackTraceAsList() {
+		List<String> stackTraceLines = new ArrayList<>();
+		for (StackTraceElement ste : Thread.currentThread().getStackTrace()) {


Not 100% sure about this one but I think that collecting the entire Thread.currentThread().getStackTrace() will include your own logging frames plus JVM internals. If what you want is the user’s call stack, consider filtering out frames until you reach the first non-logging class.

Fix: Filters the stack trace to ignore the first lines called from this package

…t of the jar

…ckage

genexusbot · 2025-07-03T13:30:27Z

Cherry pick to beta failed, 1 conflicted file in commit c6c58e5

wrappercommon/pom.xml

genexusbot · 2025-07-03T14:19:28Z

Manual cherry pick to beta success

genexusbot · 2025-07-09T13:56:54Z

Cherry pick to beta success

15dcce7

mrodbratschi requested a review from tomas-sexenian June 5, 2025 17:41

mrodbratschi and others added 10 commits June 6, 2025 12:00

Restore some changes

0390aff

New methods added

9fe1f5d

A custom resolver is added to handle messages other than MapMessages …

5757ac4

…to be compatible with the existing implementation of the log (the old implementation remains unchanged).

Add a custom .json template that uses the custom resolver

1434503

Refactoring

019dd90

Fix cyclic referencing of gxClassR

87c7b43

Merge branch 'master' into feature/log-improvement

fb92557

Fix: AndroidLogger is not abstract and does not override abstract met…

466e167

…hod isEnabled

Merge branch 'feature/log-improvement' of https://github.com/genexusl…

d9bf16e

…abs/JavaClasses into feature/log-improvement

Fix: AndroidLogger is not abstract and does not override abstract met…

ca17eb5

…hods

mrodbratschi requested a review from iroqueta June 26, 2025 18:32

iroqueta reviewed Jun 26, 2025

View reviewed changes

tomas-sexenian reviewed Jun 27, 2025

View reviewed changes

mrodbratschi added 9 commits June 30, 2025 15:45

Remove unnecessary comment

4c6e64c

Avoid code duplication

bce840b

Uses org.json instead of Gson

f5a2d66

Remove casting

9cc80d0

Ensure type safety

ebb9788

Move it to the resources folder. When compiling it will be in the roo…

018e64e

…t of the jar

Rename constant to WARN

dd7a0f8

Explicitly prevent instantiation

940f24a

Plugin rename

3381ea9

mrodbratschi and others added 5 commits July 2, 2025 10:15

Build the message only if the loglevel is enabled

89380c4

Check if the log format is JSON once.

49b138d

Filters the stack trace to ignore the first lines called from this pa…

70e2f65

…ckage

Refactoring

33f00db

Merge branch 'master' into feature/log-improvement

569f8a3

mrodbratschi requested review from iroqueta and tomas-sexenian July 2, 2025 13:50

iroqueta previously approved these changes Jul 2, 2025

View reviewed changes

mrodbratschi marked this pull request as ready for review July 3, 2025 13:29

genexusbot added the conflict label Jul 3, 2025

Merge branch 'master' into feature/log-improvement

c26b06e

genexusbot removed the conflict label Jul 3, 2025

Maintain insertion order when logging JSONs

15dcce7

mrodbratschi dismissed iroqueta’s stale review via 15dcce7 July 9, 2025 13:55

Merge branch 'master' into feature/log-improvement

c9e9a2f

mrodbratschi requested a review from iroqueta July 9, 2025 13:57

iroqueta approved these changes Jul 9, 2025

View reviewed changes


		default boolean isEnabled(int logLevel) { return false; }

		//boolean isEnabled(int logLevel, String topic);

		import org.apache.logging.log4j.layout.template.json.resolver.TemplateResolverFactory;


		@Plugin(name = "CustomMessageFactory", category = TemplateResolverFactory.CATEGORY)


		private static final String STACKTRACE_KEY = "stackTrace";
		private static final String MESSAGE_KEY = "message";

Log API Improvements #974

Are you sure you want to change the base?

Log API Improvements #974

Uh oh!

Conversation

mrodbratschi commented Jun 5, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

mrodbratschi Jul 1, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

iroqueta left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

mrodbratschi Jul 1, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

genexusbot commented Jul 3, 2025

Uh oh!

genexusbot commented Jul 3, 2025

Uh oh!

genexusbot commented Jul 9, 2025

mrodbratschi commented Jun 5, 2025 •

edited

Loading

mrodbratschi Jul 1, 2025 •

edited

Loading

mrodbratschi Jul 1, 2025 •

edited

Loading