[bugfix] Analyzed FindBugs report & fixed several SEVERE issues

src/org/exist/http/RESTServer.java

@@ -1704,7 +1704,7 @@ private void writeResourceAs(final DocumentImpl resource, final DBBroker broker,
             serializer.reset();
 
             //setup the http context
-            final HttpContext httpContext = serializer.new HttpContext();
+            final HttpContext httpContext = new HttpContext();
             final HttpRequestWrapper reqw = new HttpRequestWrapper(request, formEncoding, containerEncoding);
             httpContext.setRequest(reqw);
             httpContext.setSession(reqw.getSession(false));

src/org/exist/storage/BrokerPool.java

@@ -1165,6 +1165,8 @@ public DBBroker get(final Optional<Subject> subject) throws EXistException {
                 LOG.debug("Db instance is in service mode. Waiting for db to become available again ...");
                 wait();
             } catch(final InterruptedException e) {
+                Thread.currentThread().interrupt();
+                LOG.error("Interrupt detected");
             }
         }
 

src/org/exist/storage/NativeValueIndex.java

@@ -1154,7 +1154,7 @@ private final static class ExactMatcher implements TermMatcher {
 
         @Override
         public boolean matches(final CharSequence term) {
-            return term.toString().equals(expr);
+            return term != null && term.toString().equals(expr);
         }
     }
 
@@ -1168,7 +1168,7 @@ private final static class ContainsMatcher implements TermMatcher {
 
         @Override
         public boolean matches(final CharSequence term) {
-            return term.toString().contains(expr);
+            return term != null && term.toString().contains(expr);
         }
     }
 
@@ -1182,7 +1182,7 @@ private final static class StartsWithMatcher implements TermMatcher {
 
         @Override
         public boolean matches(final CharSequence term) {
-            return (term.toString().startsWith(expr));
+            return term != null && term.toString().startsWith(expr);
         }
     }
 
@@ -1195,7 +1195,7 @@ private final static class EndsWithMatcher implements TermMatcher {
 
         @Override
         public boolean matches(final CharSequence term) {
-            return term.toString().endsWith(expr);
+            return term != null && term.toString().endsWith(expr);
         }
     }
 

src/org/exist/storage/journal/FileSyncThread.java

@@ -19,6 +19,8 @@
  */
 package org.exist.storage.journal;
 
+import net.jcip.annotations.GuardedBy;
+
 import java.io.IOException;
 import java.nio.channels.FileChannel;
 
@@ -36,12 +38,11 @@
  */
 public class FileSyncThread extends Thread {
 
-    // guarded by latch
-    private FileChannel endOfLog;
+    @GuardedBy("latch") private FileChannel endOfLog;
     private final Object latch;
 
     // guarded by this
-    private boolean syncTriggered = false;
+    @GuardedBy("this") private boolean syncTriggered = false;
 
     // used as termination flag, volatile semantics are sufficient
     private volatile boolean shutdown = false;

src/org/exist/storage/journal/Journal.java

@@ -71,7 +71,7 @@
  */
 @ConfigurationClass("journal")
 //TODO: conf.xml refactoring <recovery> => <recovery><journal/></recovery>
-public class Journal {
+public final class Journal {
     /**
      * Logger for this class
      */
@@ -167,7 +167,7 @@ public Journal(final BrokerPool pool, final Path directory) throws EXistExceptio
         currentBuffer = ByteBuffer.allocateDirect(1024 * 1024);
 
         syncThread = new FileSyncThread(latch);
-        syncThread.start();
+        syncThread.start(); //this makes us to use class as a final only - no inheritance allowed
 
         this.syncOnCommit = pool.getConfiguration().getProperty(PROPERTY_RECOVERY_SYNC_ON_COMMIT, DEFAULT_SYNC_ON_COMMIT);
         if (LOG.isDebugEnabled()) {

src/org/exist/storage/lock/ReentrantReadWriteLock.java

@@ -210,7 +210,7 @@ public boolean acquire(final LockMode mode) throws LockException {
 
     @Override
     public synchronized void wakeUp() {
-        notify();
+        notifyAll();
     }
 
     @Override

src/org/exist/storage/serializers/Serializer.java

@@ -193,7 +193,8 @@ public abstract class Serializer implements XMLReader {
     protected Subject user = null;
 
     protected HttpContext httpContext = null;
-    public class HttpContext
+
+    public static class HttpContext
     {
     	private RequestWrapper request = null;
     	private ResponseWrapper response = null;

src/org/exist/storage/txn/Checkpoint.java

@@ -35,8 +35,7 @@ public class Checkpoint extends AbstractLoggable {
 	private long timestamp;
 	private long storedLsn;
 
-	private final DateFormat df =
-		DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM);
+	private final DateFormat df = DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM);
 
     public Checkpoint(final long transactionId) {
         this(null, transactionId);