The core.Logger#setLevel method should work like

Configurator#setLevel #2281

log4j-1.2-api/src/main/java/org/apache/log4j/legacy/core/CategoryUtil.java

@@ -27,6 +27,7 @@
 import org.apache.logging.log4j.core.Appender;
 import org.apache.logging.log4j.core.Filter;
 import org.apache.logging.log4j.core.LogEvent;
+import org.apache.logging.log4j.core.config.Configurator;
 import org.apache.logging.log4j.core.config.LoggerConfig;
 import org.apache.logging.log4j.spi.LoggerContext;
 
@@ -127,7 +128,7 @@ public static void setAdditivity(final Logger logger, final boolean additive) {
      */
     public static void setLevel(final Logger logger, final Level level) {
         if (isCore(logger)) {
-            asCore(logger).setLevel(level);
+            Configurator.setLevel(asCore(logger), level);
         }
     }
 

log4j-1.2-api/src/test/java/org/apache/log4j/LoggerTest.java

@@ -26,16 +26,19 @@
 import java.util.List;
 import java.util.Locale;
 import java.util.ResourceBundle;
+
 import org.apache.logging.log4j.core.Appender;
 import org.apache.logging.log4j.core.LogEvent;
 import org.apache.logging.log4j.core.LoggerContext;
 import org.apache.logging.log4j.core.appender.AbstractAppender;
 import org.apache.logging.log4j.core.config.ConfigurationFactory;
+import org.apache.logging.log4j.core.config.Configurator;
 import org.apache.logging.log4j.core.config.Property;
 import org.apache.logging.log4j.core.layout.PatternLayout;
 import org.apache.logging.log4j.core.test.appender.ListAppender;
 import org.junit.After;
 import org.junit.AfterClass;
+import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
@@ -76,8 +79,10 @@ public static void tearDownClass() {
     }
 
     @After
-    public void tearDown() {
+    @Before
+    public void resetTest() {
         LoggerContext.getContext().reconfigure();
+        Configurator.setAllLevels(Logger.getRootLogger().getName(), org.apache.logging.log4j.Level.DEBUG);
         a1 = null;
         a2 = null;
     }
@@ -493,6 +498,42 @@ public void testLog() {
         }
     }
 
+    @Test
+    public void testSetLevel() {
+        final Logger a = Logger.getLogger("a");
+        final Logger a_b = Logger.getLogger("a.b");
+        final Logger a_b_c = Logger.getLogger("a.b.c");
+        // test default for this test
+        assertEquals(Level.DEBUG, a.getLevel());
+        assertEquals(Level.DEBUG, a_b.getLevel());
+        assertEquals(Level.DEBUG, a_b_c.getLevel());
+        // all
+        for (Level level : new Level[] { Level.ALL, Level.DEBUG, Level.ERROR, Level.FATAL, Level.INFO, Level.OFF, Level.TRACE, Level.WARN }) {
+            a.setLevel(level);
+            assertEquals(level, a.getLevel());
+            assertEquals(level, a_b.getLevel());
+            assertEquals(level, a_b_c.getLevel());
+        }
+    }
+
+    @Test
+    public void testSetPriority() {
+        final Logger a = Logger.getLogger("a");
+        final Logger a_b = Logger.getLogger("a.b");
+        final Logger a_b_c = Logger.getLogger("a.b.c");
+        // test default for this test
+        assertEquals(Priority.DEBUG, a.getPriority());
+        assertEquals(Priority.DEBUG, a_b.getPriority());
+        assertEquals(Priority.DEBUG, a_b_c.getPriority());
+        // all
+        for (Priority level : Level.getAllPossiblePriorities()) {
+            a.setPriority(level);
+            assertEquals(level, a.getLevel());
+            assertEquals(level, a_b.getLevel());
+            assertEquals(level, a_b_c.getLevel());
+        }
+    }
+
     private static class MyLogger {
 
         private final Logger logger;

pom.xml

@@ -542,6 +542,7 @@
       <plugin>
         <groupId>org.apache.rat</groupId>
         <artifactId>apache-rat-plugin</artifactId>
+        <version>0.16.1</version>
         <configuration>
           <consoleOutput>true</consoleOutput>
           <excludes combine.children="append">

src/changelog/.2.x.x/2282_fix_1_2_set_level.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<entry xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns="http://logging.apache.org/log4j/changelog"
+       xsi:schemaLocation="http://logging.apache.org/log4j/changelog https://logging.apache.org/log4j/changelog-0.1.2.xsd"
+       type="fixed">
+  <issue id="2282" link="https://github.com/apache/logging-log4j2/issues/2282"/>
+  <description format="asciidoc">
+    The core.Logger#setLevel method should work like Configurator#setLevel.
+  </description>
+</entry>