Use slf4j-simple instead of log4j for logging

JGit uses slf4j-api as logging API.

The libraries
- org.eclipse.jgit.http.test
- org.eclipse.jgit.pgm
- org.eclipse.jgit.ssh.apache.test
- org.eclipse.jgit.test
used the outdated log4j 1.2.15 which is EOL since years.

Since both jgit command line and also the tests don't need sophisticated
logging features replace log4j with the much simpler slf4j-simple log
implementation. The org.slf4j.binding.simple 1.7.30 archive has only
25kB instead of 429kB for log4j 1.2.15

Applications using jgit are free to choose any other log implementation
supporting slf4j API.

Change-Id: I89e85cd3c76e954c3434622510975ce65dc227d4

6 files changed, 21 insertions, 41 deletions

diff --git a/org.eclipse.jgit.test/build.properties b/org.eclipse.jgit.test/build.properties
index b527a74790..212c8bd4d7 100644
--- a/org.eclipse.jgit.test/build.properties
+++ b/org.eclipse.jgit.test/build.properties
@@ -7,5 +7,4 @@ bin.includes = META-INF/,\
                plugin.properties,\
                bin-tst/,\
                bin/
-additional.bundles = org.apache.log4j,\
-                     org.slf4j.binding.log4j12
+additional.bundles = org.slf4j.binding.simple
diff --git a/org.eclipse.jgit.test/tests.bzl b/org.eclipse.jgit.test/tests.bzl
index 34df07d5e6..e201bdbcb3 100644
--- a/org.eclipse.jgit.test/tests.bzl
+++ b/org.eclipse.jgit.test/tests.bzl
@@ -36,7 +36,7 @@ def tests(tests):
             ]
         if src.endswith("SecurityManagerMissingPermissionsTest.java"):
             additional_deps = [
-                "//lib:log4j",
+                "//lib:slf4j-simple",
             ]
         if src.endswith("JDKHttpConnectionTest.java"):
             additional_deps = [
@@ -68,6 +68,7 @@ def tests(tests):
                 "//lib:javaewah",
                 "//lib:junit",
                 "//lib:slf4j-api",
+                "//lib:slf4j-simple",
                 "//org.eclipse.jgit:jgit",
                 "//org.eclipse.jgit.junit:junit",
                 "//org.eclipse.jgit.lfs:jgit-lfs",
diff --git a/org.eclipse.jgit.test/tst-rsrc/log4j.properties b/org.eclipse.jgit.test/tst-rsrc/log4j.properties
deleted file mode 100644
index 856a731ab9..0000000000
--- a/org.eclipse.jgit.test/tst-rsrc/log4j.properties
+++ /dev/null
@@ -1,14 +0,0 @@
-
-# Root logger option
-log4j.rootLogger=INFO, stdout
-
-# Direct log messages to stdout
-log4j.appender.stdout=org.apache.log4j.ConsoleAppender
-log4j.appender.stdout.Target=System.out
-log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
-log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
-log4j.appender.fileLogger.bufferedIO = true
-log4j.appender.fileLogger.bufferSize = 4096
-
-#log4j.logger.org.eclipse.jgit.util.FS = DEBUG
-#log4j.logger.org.eclipse.jgit.internal.storage.file.FileSnapshot = DEBUG
diff --git a/org.eclipse.jgit.test/tst-rsrc/simplelogger.properties b/org.eclipse.jgit.test/tst-rsrc/simplelogger.properties
index 011b2f8bb0..235fea21ac 100644
--- a/org.eclipse.jgit.test/tst-rsrc/simplelogger.properties
+++ b/org.eclipse.jgit.test/tst-rsrc/simplelogger.properties
@@ -1,9 +1,9 @@
-org.slf4j.simpleLogger.logFile = System.err
-org.slf4j.simpleLogger.cacheOutputStream = true
-org.slf4j.simpleLogger.defaultLogLevel = info
-org.slf4j.simpleLogger.showDateTime = true
-org.slf4j.simpleLogger.dateTimeFormat = HH:mm:ss.SSSXXX
-org.slf4j.simpleLogger.showThreadName = true
+org.slf4j.simpleLogger.defaultLogLevel=info
+org.slf4j.simpleLogger.logFile=System.err
+org.slf4j.simpleLogger.showDateTime=true
+org.slf4j.simpleLogger.dateTimeFormat=yyyy-MM-dd HH:mm:ss
+org.slf4j.simpleLogger.showThreadName=true
+org.slf4j.simpleLogger.showLogName=true
 
 #org.slf4j.simpleLogger.log.org.eclipse.jgit.util.FS = debug
 #org.slf4j.simpleLogger.log.org.eclipse.jgit.internal.storage.file.FileSnapshot = debug
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/SecurityManagerMissingPermissionsTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/SecurityManagerMissingPermissionsTest.java
index a07f37009e..d0fbdbd090 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/SecurityManagerMissingPermissionsTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/SecurityManagerMissingPermissionsTest.java
@@ -13,17 +13,15 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.IOException;
-import java.io.StringWriter;
+import java.io.PrintStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.security.Policy;
 import java.util.Collections;
 
-import org.apache.log4j.Logger;
-import org.apache.log4j.PatternLayout;
-import org.apache.log4j.WriterAppender;
 import org.eclipse.jgit.junit.RepositoryTestCase;
 import org.eclipse.jgit.util.FileUtils;
 import org.junit.After;
@@ -38,25 +36,21 @@ public class SecurityManagerMissingPermissionsTest extends RepositoryTestCase {
 	/**
 	 * Collects all logging sent to the logging system.
 	 */
-	private final StringWriter errorOutputWriter = new StringWriter();
-
-	/**
-	 * Appender to intercept all logging sent to the logging system.
-	 */
-	private WriterAppender appender;
+	private final ByteArrayOutputStream errorOutput = new ByteArrayOutputStream();
 
 	private SecurityManager originalSecurityManager;
 
+	private PrintStream defaultErrorOutput;
+
 	@Override
 	@Before
 	public void setUp() throws Exception {
 		originalSecurityManager = System.getSecurityManager();
 
-		appender = new WriterAppender(
-				new PatternLayout(PatternLayout.TTCC_CONVERSION_PATTERN),
-				errorOutputWriter);
-
-		Logger.getRootLogger().addAppender(appender);
+		// slf4j-simple logs to System.err, redirect it to enable asserting
+		// logged errors
+		defaultErrorOutput = System.err;
+		System.setErr(new PrintStream(errorOutput));
 
 		refreshPolicyAllPermission(Policy.getPolicy());
 		System.setSecurityManager(new SecurityManager());
@@ -85,14 +79,14 @@ public class SecurityManagerMissingPermissionsTest extends RepositoryTestCase {
 
 		addRepoToClose(git.getRepository());
 
-		assertEquals("", errorOutputWriter.toString());
+		assertEquals("", errorOutput.toString());
 	}
 
 	@Override
 	@After
 	public void tearDown() throws Exception {
 		System.setSecurityManager(originalSecurityManager);
-		Logger.getRootLogger().removeAppender(appender);
+		System.setErr(defaultErrorOutput);
 		super.tearDown();
 	}
 
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/WalkEncryptionTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/WalkEncryptionTest.java
index f289a922bb..5adf7faf20 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/WalkEncryptionTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/WalkEncryptionTest.java
@@ -99,7 +99,7 @@ import org.slf4j.LoggerFactory;
 public class WalkEncryptionTest {
 
 	/**
-	 * Logger setup: ${project_loc}/tst-rsrc/log4j.properties
+	 * Logger setup: ${project_loc}/tst-rsrc/simplelogger.properties
 	 */
 	static final Logger logger = LoggerFactory.getLogger(WalkEncryptionTest.class);