More lambda's to simplify code (some potential changes were left out because it would become less readable)

Author: dizzzz

exist-core/src/main/java/org/exist/launcher/ServiceManagerFactory.java

@@ -8,7 +8,7 @@
 
 public class ServiceManagerFactory {
 
-    private static final AtomicLazyVal<ServiceManager> WINDOWS_SERVICE_MANAGER = new AtomicLazyVal<>(() -> new WindowsServiceManager());
+    private static final AtomicLazyVal<ServiceManager> WINDOWS_SERVICE_MANAGER = new AtomicLazyVal<>(WindowsServiceManager::new);
 
     /**
      * Returns the service manager for the current

exist-core/src/main/java/org/exist/repo/Deployment.java

@@ -636,7 +636,7 @@ private void checkUserSettings(final DBBroker broker, final RequestedPerms reque
             if (!secman.hasAccount(requestedPerms.user)) {
                 final UserAider aider = new UserAider(requestedPerms.user);
                 aider.setPassword(requestedPerms.password);
-                requestedPerms.group.ifPresent(groupName -> aider.addGroup(groupName));
+                requestedPerms.group.ifPresent(aider::addGroup);
                 secman.addAccount(broker, aider);
             }
         } catch (final PermissionDeniedException | EXistException e) {

exist-core/src/main/java/org/exist/security/AbstractSubject.java

@@ -180,7 +180,7 @@ public boolean equals(final Object obj) {
        return Optional
                .ofNullable(obj)
                .flatMap(other -> other instanceof Account ? Optional.of((Account)other) : Optional.empty())
-               .map(otherAccount -> account.equals(otherAccount))
+               .map(account::equals)
                .orElse(false);
     }
 

exist-core/src/main/java/org/exist/security/internal/SecurityManagerImpl.java

@@ -935,9 +935,7 @@ private int getCurrentPrincipalId() {
          * @param updateFn A function which updates the principal db and returns a new principal id.
          */
         public void update(final BiFunction<Int2ObjectMap<V>, Integer, Integer> updateFn) {
-            write(principalDb -> {
-                this.principalId = updateFn.apply(principalDb, principalId);
-            });
+            write(principalDb -> this.principalId = updateFn.apply(principalDb, principalId));
         }
     }
 

exist-core/src/main/java/org/exist/storage/structural/NativeStructuralIndexWorker.java

@@ -651,13 +651,9 @@ private void addNode(QName qname, NodeProxy proxy) {
     		throw new IllegalArgumentException("Document id ('" + document.getDocId() + "') and proxy id ('" +
     				proxy.getOwnerDocument().getDocId() + "') differ !");
     	}
-        //Is this qname already pending ?
-        List<NodeProxy> buf = pending.get(qname);
-        if (buf == null) {
-            //Create a node list
-            buf = new ArrayList<>(50);
-            pending.put(qname, buf);
-        }
+        //Is this qname already pending ? Create a node list when not present.
+        List<NodeProxy> buf = pending.computeIfAbsent(qname, k -> new ArrayList<>(50));
+
         //Add node's proxy to the list
         buf.add(proxy);
     }

exist-core/src/main/java/org/exist/storage/txn/TransactionManager.java

@@ -537,7 +537,7 @@ private int uncommittedTransaction() {
                         return 0;
                     }
                 },
-                (a, b) -> a + b
+                Integer::sum
         );
 
         if (uncommittedCount == null) {

exist-core/src/main/java/org/exist/util/ArgumentUtil.java

@@ -67,7 +67,7 @@ public static <T> Optional<T> getOpt(final ParsedArguments parsedArguments, fina
      */
     public static <T> List<T> getListOpt(final ParsedArguments parsedArguments, final Argument<List<T>> argument) {
         return getOpt(parsedArguments, argument)
-                .orElseGet(() -> Collections.emptyList());
+                .orElseGet(Collections::emptyList);
     }
 
     /**

exist-core/src/main/java/org/exist/util/FileUtils.java

@@ -230,7 +230,7 @@ public FileVisitResult postVisitDirectory(final Path dir, final IOException exc)
     public static long sizeQuietly(final Collection<Path> paths) {
         return paths.stream().map(FileUtils::sizeQuietly)
                 .filter(size -> size != -1)
-                .reduce((a, b) -> a + b)
+                .reduce(Long::sum)
                 .orElse(-1L);
     }
 

exist-core/src/main/java/org/exist/util/PatternFactory.java

@@ -48,7 +48,7 @@ public static PatternFactory getInstance() {
     }
 
     public Pattern getPattern(final String pattern) {
-        return cache.get(pattern, ptn -> Pattern.compile(ptn));
+        return cache.get(pattern, Pattern::compile);
     }
 
     public Pattern getPattern(final String pattern, final int flags) {

exist-core/src/main/java/org/exist/xmldb/AbstractLocal.java

@@ -239,7 +239,7 @@ private static Function<DBBroker, Txn> transaction() {
         final boolean joinTransactionIfPresent = System.getProperty(PROP_JOIN_TRANSACTION_IF_PRESENT, "true")
                 .equalsIgnoreCase("true");
         if(joinTransactionIfPresent) {
-            return (broker) -> broker.continueOrBeginTransaction();
+            return DBBroker::continueOrBeginTransaction;
         } else {
             return (broker) -> broker.getBrokerPool().getTransactionManager().beginTransaction();
         }