Remove all static binders (#17)

It closes #15 Gitlab issue

Author: vitalijr2

pom.xml

@@ -66,7 +66,7 @@
 
   <properties>
     <!-- version -->
-    <revision>3.0.2</revision>
+    <revision>3.1.0</revision>
     <changelist>-SNAPSHOT</changelist>
     <sha1/>
     <!-- java and maven -->

src/main/java/org/slf4j/impl/StaticLoggerBinder.java

@@ -38,9 +38,9 @@ public class AWSLambdaServiceProvider implements SLF4JServiceProvider {
   // to avoid constant folding by the compiler, this field must *not* be final
   public static String REQUESTED_API_VERSION = "2.0.99"; // !final
 
-  private ILoggerFactory loggerFactory;
-  private IMarkerFactory markerFactory;
-  private MDCAdapter contextMapAdapter;
+  private static final ILoggerFactory loggerFactory = new LambdaLoggerFactory();
+  private static final IMarkerFactory markerFactory = new BasicMarkerFactory();
+  private static final MDCAdapter contextMapAdapter = new BasicMDCAdapter();
 
   @Override
   public ILoggerFactory getLoggerFactory() {
@@ -64,9 +64,7 @@ public String getRequestedApiVersion() {
 
   @Override
   public void initialize() {
-    loggerFactory = new LambdaLoggerFactory();
-    markerFactory = new BasicMarkerFactory();
-    contextMapAdapter = new BasicMDCAdapter();
+    // initialized by static fields
   }
 
 }

src/main/java/org/slf4j/impl/StaticMDCBinder.java

@@ -21,11 +21,11 @@
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.VisibleForTesting;
 import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.slf4j.Marker;
 import org.slf4j.event.Level;
 import org.slf4j.helpers.FormattingTuple;
 import org.slf4j.helpers.MessageFormatter;
-import org.slf4j.impl.StaticLoggerBinder;
 
 /**
  * An SLF4J {@link org.slf4j.Logger} implementation for <a href="https://aws.amazon.com/lambda/">AWS
@@ -410,7 +410,7 @@ private boolean isLevelEnabled(Level level, Marker marker) {
   }
 
   private Object readResolve() throws ObjectStreamException {
-    return StaticLoggerBinder.getSingleton().getLoggerFactory().getLogger(getName());
+    return LoggerFactory.getLogger(getName());
   }
 
 }

src/main/java/org/slf4j/impl/StaticMarkerBinder.java

@@ -25,11 +25,10 @@
 import org.jetbrains.annotations.Nullable;
 import org.slf4j.MDC;
 import org.slf4j.event.Level;
-import org.slf4j.impl.StaticLoggerBinder;
 
 class LoggerUtil {
 
-  private static final long START_TIME = System.currentTimeMillis();
+  private static final Long START_TIME = System.currentTimeMillis();
 
   private static final String ANY_NEW_LINE = "[\r\n]+";
   private static final String CARRIAGE_RETURN = "\r";
@@ -60,7 +59,7 @@ static void log(@NotNull LoggerConfiguration configuration,
       builder.append(CARRIAGE_RETURN).append(stackTraceOutputStream);
     }
 
-    synchronized (StaticLoggerBinder.getSingleton()) {
+    synchronized (START_TIME) {
       printStream.println(builder);
       printStream.flush();
     }
@@ -114,7 +113,7 @@ private static void addTimestampOrRequestId(LoggerConfiguration configuration,
   private static String getFormattedDate(DateFormat dateFormat) {
     String dateText;
 
-    synchronized (StaticLoggerBinder.getSingleton()) {
+    synchronized (START_TIME) {
       dateText = dateFormat.format(new Date());
     }