Revert "HADOOP-13470. GenericTestUtils$LogCapturer is flaky. (Contributed by Mingliang Liu)"

This reverts commit 9336a0495f99cd3fbc7ecef452eb37cfbaf57440.

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/test/GenericTestUtils.java

@@ -42,10 +42,10 @@ import org.apache.commons.logging.impl.Log4JLogger;
 import org.apache.hadoop.fs.FileUtil;
 import org.apache.hadoop.util.StringUtils;
 import org.apache.hadoop.util.Time;
+import org.apache.log4j.Layout;
 import org.apache.log4j.Level;
 import org.apache.log4j.LogManager;
 import org.apache.log4j.Logger;
-import org.apache.log4j.PatternLayout;
 import org.apache.log4j.WriterAppender;
 import org.junit.Assert;
 import org.junit.Assume;
@@ -275,35 +275,36 @@ public abstract class GenericTestUtils {
     private StringWriter sw = new StringWriter();
     private WriterAppender appender;
     private Logger logger;
-
+    
     public static LogCapturer captureLogs(Log l) {
       Logger logger = ((Log4JLogger)l).getLogger();
-      return new LogCapturer(logger);
-    }
-
-    public static LogCapturer captureLogs(org.slf4j.Logger logger) {
-      return new LogCapturer(toLog4j(logger));
+      LogCapturer c = new LogCapturer(logger);
+      return c;
     }
+    
 
     private LogCapturer(Logger logger) {
       this.logger = logger;
-      this.appender = new WriterAppender(new PatternLayout(), sw);
-      logger.addAppender(appender);
+      Layout layout = Logger.getRootLogger().getAppender("stdout").getLayout();
+      WriterAppender wa = new WriterAppender(layout, sw);
+      logger.addAppender(wa);
     }
-
+    
     public String getOutput() {
       return sw.toString();
     }
-
+    
     public void stopCapturing() {
       logger.removeAppender(appender);
+
     }
 
     public void clearOutput() {
       sw.getBuffer().setLength(0);
     }
   }
-
+  
+  
   /**
    * Mockito answer helper that triggers one latch as soon as the
    * method is called, then waits on another before continuing.

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/test/TestGenericTestUtils.java

@@ -18,16 +18,8 @@
 
 package org.apache.hadoop.test;
 
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-
 import org.junit.Test;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import static org.junit.Assert.assertTrue;
-
 public class TestGenericTestUtils extends GenericTestUtils {
 
   @Test
@@ -83,40 +75,4 @@ public class TestGenericTestUtils extends GenericTestUtils {
     }
   }
 
-  @Test(timeout = 10000)
-  public void testLogCapturer() {
-    final Log log = LogFactory.getLog(TestGenericTestUtils.class);
-    LogCapturer logCapturer = LogCapturer.captureLogs(log);
-    final String infoMessage = "info message";
-    // test get output message
-    log.info(infoMessage);
-    assertTrue(logCapturer.getOutput().endsWith(
-        String.format(infoMessage + "%n")));
-    // test clear output
-    logCapturer.clearOutput();
-    assertTrue(logCapturer.getOutput().isEmpty());
-    // test stop capturing
-    logCapturer.stopCapturing();
-    log.info(infoMessage);
-    assertTrue(logCapturer.getOutput().isEmpty());
-  }
-
-  @Test(timeout = 10000)
-  public void testLogCapturerSlf4jLogger() {
-    final Logger logger = LoggerFactory.getLogger(TestGenericTestUtils.class);
-    LogCapturer logCapturer = LogCapturer.captureLogs(logger);
-    final String infoMessage = "info message";
-    // test get output message
-    logger.info(infoMessage);
-    assertTrue(logCapturer.getOutput().endsWith(
-        String.format(infoMessage + "%n")));
-    // test clear output
-    logCapturer.clearOutput();
-    assertTrue(logCapturer.getOutput().isEmpty());
-    // test stop capturing
-    logCapturer.stopCapturing();
-    logger.info(infoMessage);
-    assertTrue(logCapturer.getOutput().isEmpty());
-  }
-
 }