minor code cleanups

- more private final fields
- avoiding C-style array declarations
- few typos, notably JPlarformLogger -> JPlatformLogger

jcl-over-slf4j/src/main/java/org/apache/commons/logging/impl/SLF4JLocationAwareLog.java

@@ -43,7 +43,7 @@ public class SLF4JLocationAwareLog implements Log, Serializable {
 
     // in both Log4jLogger and Jdk14Logger classes in the original JCL, the
     // logger instance is transient
-    private transient LocationAwareLogger logger;
+    private final transient LocationAwareLogger logger;
 
     private static final String FQCN = SLF4JLocationAwareLog.class.getName();
 

jcl-over-slf4j/src/main/java/org/apache/commons/logging/impl/SLF4JLog.java

@@ -42,7 +42,7 @@ public class SLF4JLog implements Log, Serializable {
 
     // in both Log4jLogger and Jdk14Logger classes in the original JCL, the
     // logger instance is transient
-    private transient Logger logger;
+    private final transient Logger logger;
 
     public SLF4JLog(Logger logger) {
         this.logger = logger;

jcl-over-slf4j/src/main/java/org/apache/commons/logging/impl/SLF4JLogFactory.java

@@ -110,7 +110,7 @@ public String[] getAttributeNames() {
         while (keys.hasMoreElements()) {
             names.add((String) keys.nextElement());
         }
-        String results[] = new String[names.size()];
+        String[] results = new String[names.size()];
         for (int i = 0; i < results.length; i++) {
             results[i] = (String) names.get(i);
         }

jul-to-slf4j/src/main/java/org/slf4j/bridge/SLF4JBridgeHandler.java

@@ -174,8 +174,8 @@ public static boolean isInstalled() {
     public static void removeHandlersForRootLogger() {
         java.util.logging.Logger rootLogger = getRootLogger();
         java.util.logging.Handler[] handlers = rootLogger.getHandlers();
-        for (int i = 0; i < handlers.length; i++) {
-            rootLogger.removeHandler(handlers[i]);
+        for (Handler handler : handlers) {
+            rootLogger.removeHandler(handler);
         }
     }
 

log4j-over-slf4j/src/main/java/org/apache/log4j/Category.java

@@ -45,12 +45,12 @@ public class Category {
 
     private static final String CATEGORY_FQCN = Category.class.getName();
 
-    private String name;
+    private final String name;
 
     protected org.slf4j.Logger slf4jLogger;
     private org.slf4j.spi.LocationAwareLogger locationAwareLogger;
 
-    private static Marker FATAL_MARKER = MarkerFactory.getMarker("FATAL");
+    private static final Marker FATAL_MARKER = MarkerFactory.getMarker("FATAL");
 
     Category(String name) {
         this.name = name;

log4j-over-slf4j/src/main/java/org/apache/log4j/Log4jLoggerFactory.java

@@ -33,7 +33,7 @@
 class Log4jLoggerFactory {
 
     // String, Logger
-    private static ConcurrentMap<String, Logger> log4jLoggers = new ConcurrentHashMap<>();
+    private static final ConcurrentMap<String, Logger> log4jLoggers = new ConcurrentHashMap<>();
 
     public static Logger getLogger(String name) {
         org.apache.log4j.Logger instance = log4jLoggers.get(name);

slf4j-api/src/main/java/org/slf4j/LoggerFactory.java

@@ -182,7 +182,7 @@ private static void reportIgnoredStaticLoggerBinders(Set<URL> staticLoggerBinder
 
     // We need to use the name of the StaticLoggerBinder class, but we can't
     // reference the class itself.
-    private static String STATIC_LOGGER_BINDER_PATH = "org/slf4j/impl/StaticLoggerBinder.class";
+    private static final String STATIC_LOGGER_BINDER_PATH = "org/slf4j/impl/StaticLoggerBinder.class";
 
     static Set<URL> findPossibleStaticLoggerBinderPathSet() {
         // use Set instead of list in order to deal with bug #138

slf4j-api/src/main/java/org/slf4j/helpers/BasicMDCAdapter.java

@@ -43,7 +43,7 @@
  */
 public class BasicMDCAdapter implements MDCAdapter {
 
-    private InheritableThreadLocal<Map<String, String>> inheritableThreadLocal = new InheritableThreadLocal<Map<String, String>>() {
+    private final InheritableThreadLocal<Map<String, String>> inheritableThreadLocal = new InheritableThreadLocal<Map<String, String>>() {
         @Override
         protected Map<String, String> childValue(Map<String, String> parentValue) {
             if (parentValue == null) {

slf4j-api/src/main/java/org/slf4j/helpers/BasicMarker.java

@@ -40,7 +40,7 @@ public class BasicMarker implements Marker {
 
     private static final long serialVersionUID = -2849567615646933777L;
     private final String name;
-    private List<Marker> referenceList = new CopyOnWriteArrayList<>();
+    private final List<Marker> referenceList = new CopyOnWriteArrayList<>();
 
     BasicMarker(String name) {
         if (name == null) {
@@ -128,9 +128,9 @@ public boolean contains(String name) {
         return false;
     }
 
-    private static String OPEN = "[ ";
-    private static String CLOSE = " ]";
-    private static String SEP = ", ";
+    private static final String OPEN = "[ ";
+    private static final String CLOSE = " ]";
+    private static final String SEP = ", ";
 
     public boolean equals(Object obj) {
         if (this == obj)

slf4j-api/src/main/java/org/slf4j/helpers/FormattingTuple.java

@@ -33,9 +33,9 @@ public class FormattingTuple {
 
     static public FormattingTuple NULL = new FormattingTuple(null);
 
-    private String message;
-    private Throwable throwable;
-    private Object[] argArray;
+    private final String message;
+    private final Throwable throwable;
+    private final Object[] argArray;
 
     public FormattingTuple(String message) {
         this(message, null, null);

slf4j-api/src/main/java/org/slf4j/helpers/NOP_FallbackServiceProvider.java

@@ -14,9 +14,9 @@ public class NOP_FallbackServiceProvider 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 = new NOPLoggerFactory();
-    private IMarkerFactory markerFactory = new BasicMarkerFactory();
-    private MDCAdapter mdcAdapter = new NOPMDCAdapter();
+    private final ILoggerFactory loggerFactory = new NOPLoggerFactory();
+    private final IMarkerFactory markerFactory = new BasicMarkerFactory();
+    private final MDCAdapter mdcAdapter = new NOPMDCAdapter();
 
 
     @Override

slf4j-api/src/main/java/org/slf4j/helpers/SubstituteLogger.java

@@ -53,7 +53,7 @@ public class SubstituteLogger implements Logger {
     private Boolean delegateEventAware;
     private Method logMethodCache;
     private EventRecodingLogger eventRecodingLogger;
-    private Queue<SubstituteLoggingEvent> eventQueue;
+    private final Queue<SubstituteLoggingEvent> eventQueue;
 
     public final boolean createdPostInitialization;
 

slf4j-api/src/main/java/org/slf4j/helpers/SubstituteServiceProvider.java

@@ -6,9 +6,9 @@
 import org.slf4j.spi.SLF4JServiceProvider;
 
 public class SubstituteServiceProvider implements SLF4JServiceProvider {
-    private SubstituteLoggerFactory loggerFactory = new SubstituteLoggerFactory();
-    private IMarkerFactory markerFactory = new BasicMarkerFactory();
-    private MDCAdapter mdcAdapter = new BasicMDCAdapter();
+    private final SubstituteLoggerFactory loggerFactory = new SubstituteLoggerFactory();
+    private final IMarkerFactory markerFactory = new BasicMarkerFactory();
+    private final MDCAdapter mdcAdapter = new BasicMDCAdapter();
 
     @Override
     public ILoggerFactory getLoggerFactory() {

slf4j-api/src/main/java/org/slf4j/spi/CallerBoundaryAware.java

@@ -1,10 +1,12 @@
 package org.slf4j.spi;
 
+import org.slf4j.event.LoggingEvent;
+
 /**
  * Additional interface to {@link LoggingEventBuilder} and 
- * {@link qorg.slf4j.event.LoggingEvent LoggingEvent}. 
+ * {@link org.slf4j.event.LoggingEvent LoggingEvent}.
  * 
- * Implementations of {@link LoggingEventBuilder} and  {@link LoggingEvent} may optionally 
+ * Implementations of {@link LoggingEventBuilder} and  {@link LoggingEvent} may optionally
  * implement {@link CallerBoundaryAware} in order to support caller info extraction.
  *
  * This interface is intended for use by logging backends or logging bridges. 

slf4j-api/src/main/java/org/slf4j/spi/SLF4JServiceProvider.java

@@ -3,6 +3,7 @@
 import org.slf4j.ILoggerFactory;
 import org.slf4j.IMarkerFactory;
 import org.slf4j.LoggerFactory;
+import org.slf4j.MDC;
 
 /**
  * This interface based on {@link java.util.ServiceLoader} paradigm. 
@@ -31,7 +32,7 @@ public interface SLF4JServiceProvider {
     public IMarkerFactory getMarkerFactory();
 
     /**
-     * Return the instnace of {@link MDCAdapter} that
+     * Return the instance of {@link MDCAdapter} that
      * {@link MDC} should bind to.
      * 
      * @return instance of {@link MDCAdapter} 

slf4j-api/src/test/java/org/slf4j/LoggerAccessingThread.java

@@ -29,7 +29,7 @@
 import java.util.concurrent.atomic.AtomicLong;
 
 public class LoggerAccessingThread extends Thread {
-    private static int LOOP_LEN = 32;
+    private static final int LOOP_LEN = 32;
 
     final CyclicBarrier barrier;
     final int count;

slf4j-api/src/test/java/org/slf4j/helpers/SubstituteLoggerFactoryTest.java

@@ -36,7 +36,7 @@
 import java.util.Set;
 
 public class SubstituteLoggerFactoryTest {
-    private SubstituteLoggerFactory factory = new SubstituteLoggerFactory();
+    private final SubstituteLoggerFactory factory = new SubstituteLoggerFactory();
 
     @Test
     public void testFactory() {

slf4j-ext/src/main/java/org/slf4j/instrumentation/LogTransformer.java

@@ -135,8 +135,8 @@ public Builder level(String level) {
         }
     }
 
-    private String level;
-    private String levelEnabled;
+    private final String level;
+    private final String levelEnabled;
 
     private LogTransformer(Builder builder) {
         String s = "WARNING: javassist not available on classpath for javaagent, log statements will not be added";
@@ -156,10 +156,10 @@ private LogTransformer(Builder builder) {
         this.levelEnabled = "is" + builder.level.substring(0, 1).toUpperCase() + builder.level.substring(1) + "Enabled";
     }
 
-    private boolean addEntryExit;
+    private final boolean addEntryExit;
     // private boolean addVariableAssignment;
-    private boolean verbose;
-    private String[] ignore;
+    private final boolean verbose;
+    private final String[] ignore;
 
     public byte[] transform(ClassLoader loader, String className, Class<?> clazz, ProtectionDomain domain, byte[] bytes) {
 

slf4j-ext/src/test/java/org/slf4j/profiler/SortAndPruneComposites.java

@@ -50,7 +50,7 @@ public int[] sortAndPruneComposites() {
         int[] sortedArray = sort();
         // start a new stopwatch called PRUNE_COMPOSITES
         sortProfiler.start("PRUNE_COMPOSITES");
-        int result[] = pruneComposites(sortedArray);
+        int[] result = pruneComposites(sortedArray);
 
         return result;
     }

slf4j-jdk-platform-logging/src/main/java/org/slf4j/jdk/platform/logging/SLF4JPlarformLoggerFactory.java

@@ -31,28 +31,28 @@
 import org.slf4j.LoggerFactory;
 
 /**
- * Manages instances of {@link SLF4JPlarformLogger}.
+ * Manages instances of {@link SLF4JPlatformLogger}.
  * 
  * @since 1.3.0
  * @author Ceki
  *
  */
 public class SLF4JPlarformLoggerFactory {
-    ConcurrentMap<String, SLF4JPlarformLogger> loggerMap = new ConcurrentHashMap<>();
+    ConcurrentMap<String, SLF4JPlatformLogger> loggerMap = new ConcurrentHashMap<>();
 
     /**
-     * Return an appropriate {@link SLF4JPlarformLogger} instance by name.
+     * Return an appropriate {@link SLF4JPlatformLogger} instance by name.
      */
-    public SLF4JPlarformLogger getLogger(String loggerName) {
+    public SLF4JPlatformLogger getLogger(String loggerName) {
 
 
-        SLF4JPlarformLogger spla = loggerMap.get(loggerName);
+        SLF4JPlatformLogger spla = loggerMap.get(loggerName);
         if (spla != null) {
             return spla;
         } else {
             Logger slf4jLogger = LoggerFactory.getLogger(loggerName);
-            SLF4JPlarformLogger newInstance = new SLF4JPlarformLogger(slf4jLogger);
-            SLF4JPlarformLogger oldInstance = loggerMap.putIfAbsent(loggerName, newInstance);
+            SLF4JPlatformLogger newInstance = new SLF4JPlatformLogger(slf4jLogger);
+            SLF4JPlatformLogger oldInstance = loggerMap.putIfAbsent(loggerName, newInstance);
             return oldInstance == null ? newInstance : oldInstance;
         }
     }

slf4j-jdk-platform-logging/src/main/java/org/slf4j/jdk/platform/logging/SLF4JPlarformLogger.java → slf4j-jdk-platform-logging/src/main/java/org/slf4j/jdk/platform/logging/SLF4JPlatformLogger.java

@@ -37,13 +37,13 @@
  * Adapts {@link Logger} to {@link System.Logger}.
  * @since 2.0.0
  */
-class SLF4JPlarformLogger implements System.Logger {
+class SLF4JPlatformLogger implements System.Logger {
 
-    static private String PRESUMED_CALLER_BOUNDARY = System.Logger.class.getName();
+    static private final String PRESUMED_CALLER_BOUNDARY = System.Logger.class.getName();
 
     private final Logger slf4jLogger;
 
-    public SLF4JPlarformLogger(Logger logger) {
+    public SLF4JPlatformLogger(Logger logger) {
         this.slf4jLogger = requireNonNull(logger);
     }
 

slf4j-jdk-platform-logging/src/main/java/org/slf4j/jdk/platform/logging/SLF4JSystemLoggerFinder.java

@@ -52,7 +52,7 @@ public System.Logger getLogger(String name, Module module) {
         // is updated to forward a module, we should do that here.
         //
         // [1] https://openjdk.java.net/jeps/264
-         SLF4JPlarformLogger adapter = platformLoggerFactory.getLogger(name);
+        SLF4JPlatformLogger adapter = platformLoggerFactory.getLogger(name);
         return adapter;
     }
 

slf4j-jdk14/src/main/java/org/slf4j/jul/JDK14LoggerAdapter.java

@@ -216,7 +216,7 @@ final private void fillCallerData(String callerFQCN, LogRecord record) {
     static String SUBSTITUE = SubstituteLogger.class.getName();
     static String FLUENT = DefaultLoggingEventBuilder.class.getName();
 
-    static String BARRIER_CLASSES[] = new String[] { SUPER_OF_SUPER, SUPER, SELF, SUBSTITUE, FLUENT };
+    static String[] BARRIER_CLASSES = new String[] { SUPER_OF_SUPER, SUPER, SELF, SUBSTITUE, FLUENT };
 
     private boolean barrierMatch(String callerFQCN, String candidateClassName) {
         if (candidateClassName.equals(callerFQCN))

slf4j-jdk14/src/test/java/org/slf4j/issue/LoggerSerializationTest.java

@@ -47,7 +47,7 @@ public class LoggerSerializationTest {
     static class LoggerHolder implements Serializable {
         private static final long serialVersionUID = 1L;
 
-        private Logger log = LoggerFactory.getLogger(LoggerHolder.class);
+        private final Logger log = LoggerFactory.getLogger(LoggerHolder.class);
 
         public String toString() {
             return "log=" + getLog();

slf4j-log4j12/src/test/java/org/slf4j/log4j12/MDCFriendTest.java

@@ -11,7 +11,7 @@
 
 public class MDCFriendTest {
 
-    private static Random random = new Random();
+    private static final Random random = new Random();
     int diff = random.nextInt(1024 * 8);
 
     @Test

slf4j-migrator/src/main/java/org/slf4j/migrator/internal/MigratorFrame.java

@@ -58,8 +58,8 @@ public class MigratorFrame extends JFrame implements ActionListener {
     static final int X_SIZE = 700;
     static final int Y_SIZE = 400;
 
-    private SpringLayout layoutManager = new SpringLayout();
-    private SpringLayoutHelper slh = new SpringLayoutHelper(layoutManager, BASIC_PADDING);
+    private final SpringLayout layoutManager = new SpringLayout();
+    private final SpringLayoutHelper slh = new SpringLayoutHelper(layoutManager, BASIC_PADDING);
 
     private JLabel migrationLabel;
 

slf4j-migrator/src/main/java/org/slf4j/migrator/line/JCLRuleSet.java

@@ -36,7 +36,7 @@
  */
 public class JCLRuleSet implements RuleSet {
 
-    private ArrayList<ConversionRule> conversionRuleList;
+    private final ArrayList<ConversionRule> conversionRuleList;
 
     public JCLRuleSet() {
         // matching : import org.apache.commons.logging.LogFactory;

slf4j-migrator/src/main/java/org/slf4j/migrator/line/JULRuleSet.java

@@ -36,7 +36,7 @@
  */
 public class JULRuleSet implements RuleSet {
 
-    private ArrayList<ConversionRule> conversionRuleList;
+    private final ArrayList<ConversionRule> conversionRuleList;
 
     public JULRuleSet() {
 

slf4j-migrator/src/main/java/org/slf4j/migrator/line/Log4jRuleSet.java

@@ -30,7 +30,7 @@
 
 public class Log4jRuleSet implements RuleSet {
 
-    private ArrayList<ConversionRule> conversionRuleList;
+    private final ArrayList<ConversionRule> conversionRuleList;
 
     public Log4jRuleSet() {
 

slf4j-migrator/src/main/java/org/slf4j/migrator/line/MultiGroupConversionRule.java

@@ -40,8 +40,8 @@ public class MultiGroupConversionRule implements ConversionRule {
     // our conversion reg-expressions
     final private static int MAX_GROUPS = 10;
 
-    private Pattern pattern;
-    private String[] replacementTable = new String[MAX_GROUPS];
+    private final Pattern pattern;
+    private final String[] replacementTable = new String[MAX_GROUPS];
 
     public MultiGroupConversionRule(Pattern pattern) {
         this.pattern = pattern;

slf4j-migrator/src/test/java/org/slf4j/migrator/helper/RandomHelper.java

@@ -28,7 +28,7 @@
 
 public class RandomHelper {
 
-    private Random random = new Random(100);
+    private final Random random = new Random(100);
     final char folderSeparator;
 
     RandomHelper(char folderSeparator) {

slf4j-migrator/src/test/java/org/slf4j/migrator/line/TrivialMatcher.java

@@ -35,7 +35,7 @@
 
 class TrivialMatcher implements RuleSet {
 
-    private ArrayList<ConversionRule> conversionRuleList;
+    private final ArrayList<ConversionRule> conversionRuleList;
 
     public TrivialMatcher() {
         // simple rule no capturing group is defined, we use default capturing group which is group zero