From 49a62de92aed3214669d000d5798e63bcc696bf0 Mon Sep 17 00:00:00 2001 From: arimu1 <19286898+arimu1@users.noreply.github.com> Date: Thu, 6 Aug 2026 08:49:32 +0700 Subject: [PATCH 1/2] fix: treat null parameters as empty in CsvParameterLayout SimpleMessage and other parameter-less Message implementations return null from getParameters(). Commons CSV printRecord NPEs on a null values array, so plain logger.info("text") events failed the layout. Use Constants.EMPTY_OBJECT_ARRAY so an empty CSV record is emitted instead. Fixes #4243 Signed-off-by: arimu1 <19286898+arimu1@users.noreply.github.com> --- .../core/layout/CsvParameterLayoutTest.java | 16 ++++++++++++++++ .../log4j/core/layout/CsvParameterLayout.java | 3 ++- ...43_fix_CsvParameterLayout_null_parameters.xml | 12 ++++++++++++ 3 files changed, 30 insertions(+), 1 deletion(-) create mode 100644 src/changelog/.2.x.x/4243_fix_CsvParameterLayout_null_parameters.xml diff --git a/log4j-core-test/src/test/java/org/apache/logging/log4j/core/layout/CsvParameterLayoutTest.java b/log4j-core-test/src/test/java/org/apache/logging/log4j/core/layout/CsvParameterLayoutTest.java index 50bff2beac7..466e5ba4b1a 100644 --- a/log4j-core-test/src/test/java/org/apache/logging/log4j/core/layout/CsvParameterLayoutTest.java +++ b/log4j-core-test/src/test/java/org/apache/logging/log4j/core/layout/CsvParameterLayoutTest.java @@ -29,11 +29,14 @@ import org.apache.logging.log4j.Level; import org.apache.logging.log4j.LogManager; import org.apache.logging.log4j.core.Appender; +import org.apache.logging.log4j.core.LogEvent; import org.apache.logging.log4j.core.Logger; +import org.apache.logging.log4j.core.impl.Log4jLogEvent; import org.apache.logging.log4j.core.test.appender.ListAppender; import org.apache.logging.log4j.core.test.categories.Layouts; import org.apache.logging.log4j.core.test.junit.LoggerContextRule; import org.apache.logging.log4j.message.ObjectArrayMessage; +import org.apache.logging.log4j.message.SimpleMessage; import org.apache.logging.log4j.test.junit.ThreadContextRule; import org.junit.Assert; import org.junit.Rule; @@ -170,6 +173,19 @@ public void testLayoutTab() throws Exception { testLayoutNormalApi(root, CsvParameterLayout.createLayout(CSVFormat.TDF), true); } + @Test + public void testNullParametersProduceEmptyRecord() { + // SimpleMessage#getParameters() returns null; must not NPE (GH-4243) + final AbstractCsvLayout layout = CsvParameterLayout.createDefaultLayout(); + final LogEvent event = Log4jLogEvent.newBuilder() + .setLoggerName("test") + .setLevel(Level.INFO) + .setMessage(new SimpleMessage("plain text without parameters")) + .build(); + final String result = layout.toSerializable(event); + Assert.assertEquals(layout.getFormat().getRecordSeparator(), result); + } + @Test public void testLogJsonArgument() throws InterruptedException { final ListAppender appender = init.getAppender("List"); diff --git a/log4j-core/src/main/java/org/apache/logging/log4j/core/layout/CsvParameterLayout.java b/log4j-core/src/main/java/org/apache/logging/log4j/core/layout/CsvParameterLayout.java index c680ab792d0..c738c80137e 100644 --- a/log4j-core/src/main/java/org/apache/logging/log4j/core/layout/CsvParameterLayout.java +++ b/log4j-core/src/main/java/org/apache/logging/log4j/core/layout/CsvParameterLayout.java @@ -30,6 +30,7 @@ import org.apache.logging.log4j.core.config.plugins.PluginFactory; import org.apache.logging.log4j.message.Message; import org.apache.logging.log4j.status.StatusLogger; +import org.apache.logging.log4j.util.Constants; /** * A Comma-Separated Value (CSV) layout to log event parameters. @@ -95,7 +96,7 @@ public String toSerializable(final LogEvent event) { final Object[] parameters = message.getParameters(); final StringBuilder buffer = getStringBuilder(); try { - getFormat().printRecord(buffer, parameters); + getFormat().printRecord(buffer, parameters == null ? Constants.EMPTY_OBJECT_ARRAY : parameters); return buffer.toString(); } catch (final IOException e) { StatusLogger.getLogger().error(message, e); diff --git a/src/changelog/.2.x.x/4243_fix_CsvParameterLayout_null_parameters.xml b/src/changelog/.2.x.x/4243_fix_CsvParameterLayout_null_parameters.xml new file mode 100644 index 00000000000..57004d57d0c --- /dev/null +++ b/src/changelog/.2.x.x/4243_fix_CsvParameterLayout_null_parameters.xml @@ -0,0 +1,12 @@ + + + + + Fix `NullPointerException` in `CsvParameterLayout` when a log event has no parameters (for example `SimpleMessage`). + + From 411009632404fcd0ee9dffd0fb008cd61eb1d031 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Volkan=20Yaz=C4=B1c=C4=B1?= Date: Thu, 27 Aug 2026 13:00:42 +0200 Subject: [PATCH 2/2] Add PR link to the changelog --- .../.2.x.x/4243_fix_CsvParameterLayout_null_parameters.xml | 1 + 1 file changed, 1 insertion(+) diff --git a/src/changelog/.2.x.x/4243_fix_CsvParameterLayout_null_parameters.xml b/src/changelog/.2.x.x/4243_fix_CsvParameterLayout_null_parameters.xml index 57004d57d0c..2849ce03f28 100644 --- a/src/changelog/.2.x.x/4243_fix_CsvParameterLayout_null_parameters.xml +++ b/src/changelog/.2.x.x/4243_fix_CsvParameterLayout_null_parameters.xml @@ -6,6 +6,7 @@ https://logging.apache.org/xml/ns/log4j-changelog-0.xsd" type="fixed"> + Fix `NullPointerException` in `CsvParameterLayout` when a log event has no parameters (for example `SimpleMessage`).