Java language level updates concerning Maps. (#1008)

* Java language level updates concerning Maps.

* Reverts when comments indicated no sync can happen.

src/main/java/io/ebean/dbmigration/ddlgeneration/platform/BaseTableDdl.java

@@ -696,11 +696,7 @@ public class BaseTableDdl implements TableDdl {
    */
   protected void regenerateHistoryTriggers(String baseTableName, HistoryTableUpdate.Change change, String column) {
 
-    HistoryTableUpdate update = regenerateHistoryTriggers.get(baseTableName);
-    if (update == null) {
-      update = new HistoryTableUpdate(baseTableName);
-      regenerateHistoryTriggers.put(baseTableName, update);
-    }
+    HistoryTableUpdate update = regenerateHistoryTriggers.computeIfAbsent(baseTableName, HistoryTableUpdate::new);
     update.add(change, column);
   }
 

src/main/java/io/ebean/dbmigration/model/PendingDrops.java

@@ -23,11 +23,7 @@ public class PendingDrops {
    */
   public void add(MigrationVersion version, ChangeSet changeSet) {
 
-    Entry entry = map.get(version.normalised());
-    if (entry == null) {
-      entry = new Entry(version);
-      map.put(version.normalised(), entry);
-    }
+    Entry entry = map.computeIfAbsent(version.normalised(), k -> new Entry(version));
     entry.add(changeSet);
   }
 

src/main/java/io/ebean/text/PathProperties.java

@@ -89,11 +89,7 @@ public class PathProperties implements FetchPath {
   }
 
   Props getProps(String path) {
-    Props props = pathMap.get(path);
-    if (props == null) {
-      props = new Props(this, null, path);
-      pathMap.put(path, props);
-    }
+    Props props = pathMap.computeIfAbsent(path, p -> new Props(this, null, p));
     return props;
   }
 

src/main/java/io/ebeaninternal/api/BindParams.java

@@ -169,11 +169,7 @@ public class BindParams implements Serializable {
   }
 
   private Param getParam(String name) {
-    Param p = namedParameters.get(name);
-    if (p == null) {
-      p = new Param();
-      namedParameters.put(name, p);
-    }
+    Param p = namedParameters.computeIfAbsent(name, k -> new Param());
     return p;
   }
 

src/main/java/io/ebeaninternal/server/autotune/service/ProfileManager.java

@@ -103,11 +103,7 @@ public class ProfileManager implements ProfilingListener {
 
   private ProfileOrigin getProfileOrigin(ObjectGraphOrigin originQueryPoint) {
     synchronized (monitor) {
-      ProfileOrigin stats = profileMap.get(originQueryPoint.getKey());
-      if (stats == null) {
-        stats = new ProfileOrigin(originQueryPoint, queryTuningAddVersion, profilingBase, profilingRate);
-        profileMap.put(originQueryPoint.getKey(), stats);
-      }
+      ProfileOrigin stats = profileMap.computeIfAbsent(originQueryPoint.getKey(), k -> new ProfileOrigin(originQueryPoint, queryTuningAddVersion, profilingBase, profilingRate));
       return stats;
     }
   }

src/main/java/io/ebeaninternal/server/cache/CacheChangeSet.java

@@ -122,11 +122,7 @@ public class CacheChangeSet {
    */
   private ManyChange many(BeanDescriptor<?> desc, String manyProperty) {
     ManyKey key = new ManyKey(desc, manyProperty);
-    ManyChange manyChange = manyChangeMap.get(key);
-    if (manyChange == null) {
-      manyChange = new ManyChange(key);
-      manyChangeMap.put(key, manyChange);
-    }
+    ManyChange manyChange = manyChangeMap.computeIfAbsent(key, ManyChange::new);
     return manyChange;
   }
 

src/main/java/io/ebeaninternal/server/deploy/BeanDescriptor.java

@@ -1996,11 +1996,7 @@ public class BeanDescriptor<T> implements MetaBeanInfo, BeanType<T> {
   }
 
   public ElComparator<T> getElComparator(String propNameOrSortBy) {
-    ElComparator<T> c = comparatorCache.get(propNameOrSortBy);
-    if (c == null) {
-      c = createComparator(propNameOrSortBy);
-      comparatorCache.put(propNameOrSortBy, c);
-    }
+    ElComparator<T> c = comparatorCache.computeIfAbsent(propNameOrSortBy, this::createComparator);
     return c;
   }
 

src/main/java/io/ebeaninternal/server/deploy/BeanDescriptorManager.java

@@ -481,11 +481,7 @@ public class BeanDescriptorManager implements BeanDescriptorMap {
       String baseTable = desc.getBaseTable();
       if (baseTable != null) {
         baseTable = baseTable.toLowerCase();
-        List<BeanDescriptor<?>> list = tableToDescMap.get(baseTable);
-        if (list == null) {
-          list = new ArrayList<>(1);
-          tableToDescMap.put(baseTable, list);
-        }
+        List<BeanDescriptor<?>> list = tableToDescMap.computeIfAbsent(baseTable, k -> new ArrayList<>(1));
         list.add(desc);
       }
       if (desc.getEntityType() == EntityType.VIEW && desc.isQueryCaching()) {
@@ -495,11 +491,7 @@ public class BeanDescriptorManager implements BeanDescriptorMap {
         if (dependentTables != null && dependentTables.length > 0) {
           for (String depTable : dependentTables) {
             depTable = depTable.toLowerCase();
-            List<BeanDescriptor<?>> list = tableToViewDescMap.get(depTable);
-            if (list == null) {
-              list = new ArrayList<>(1);
-              tableToViewDescMap.put(depTable, list);
-            }
+            List<BeanDescriptor<?>> list = tableToViewDescMap.computeIfAbsent(depTable, k -> new ArrayList<>(1));
             list.add(desc);
           }
         }

src/main/java/io/ebeaninternal/server/expression/PrepareDocNested.java

@@ -79,11 +79,7 @@ class PrepareDocNested {
     for (int i = 0; i < origSize; i++) {
       SpiExpression expr = origUnderlying.get(i);
       String nestedPath = expr.nestedPath(beanDescriptor);
-      Group group = groups.get(nestedPath);
-      if (group == null) {
-        group = new Group(nestedPath);
-        groups.put(nestedPath, group);
-      }
+      Group group = groups.computeIfAbsent(nestedPath, Group::new);
       group.list.add(expr);
     }
 

src/main/java/io/ebeaninternal/server/loadcontext/DLoadContext.java

@@ -211,11 +211,7 @@ public class DLoadContext implements LoadContext {
   @Override
   public ObjectGraphNode getObjectGraphNode(String path) {
 
-    ObjectGraphNode node = nodePathMap.get(path);
-    if (node == null) {
-      node = createObjectGraphNode(path);
-      nodePathMap.put(path, node);
-    }
+    ObjectGraphNode node = nodePathMap.computeIfAbsent(path, this::createObjectGraphNode);
 
     return node;
   }
@@ -284,11 +280,7 @@ public class DLoadContext implements LoadContext {
     if (path == null) {
       return rootBeanContext;
     }
-    DLoadBeanContext beanContext = beanMap.get(path);
-    if (beanContext == null) {
-      beanContext = createBeanContext(path, defaultBatchSize, null);
-      beanMap.put(path, beanContext);
-    }
+    DLoadBeanContext beanContext = beanMap.computeIfAbsent(path, p -> createBeanContext(p, defaultBatchSize, null));
     return beanContext;
   }
 
@@ -314,11 +306,7 @@ public class DLoadContext implements LoadContext {
     if (path == null) {
       throw new RuntimeException("path is null?");
     }
-    DLoadManyContext ctx = manyMap.get(path);
-    if (ctx == null) {
-      ctx = createManyContext(path, defaultBatchSize, null);
-      manyMap.put(path, ctx);
-    }
+    DLoadManyContext ctx = manyMap.computeIfAbsent(path, p -> createManyContext(p, defaultBatchSize, null));
     return ctx;
   }
 

src/main/java/io/ebeaninternal/server/querydefn/DefaultOrmQuery.java

@@ -1568,11 +1568,7 @@ public class DefaultOrmQuery<T> implements SpiQuery<T> {
       namedParams = new HashMap<>();
     }
 
-    ONamedParam param = namedParams.get(name);
-    if (param == null) {
-      param = new ONamedParam(name);
-      namedParams.put(name, param);
-    }
+    ONamedParam param = namedParams.computeIfAbsent(name, ONamedParam::new);
     return param;
   }
 

src/main/java/io/ebeaninternal/server/transaction/BeanPersistIdMap.java

@@ -39,11 +39,7 @@ public final class BeanPersistIdMap {
 
   private BeanPersistIds getPersistIds(BeanDescriptor<?> desc) {
     String beanType = desc.getFullName();
-    BeanPersistIds r = beanMap.get(beanType);
-    if (r == null) {
-      r = new BeanPersistIds(desc);
-      beanMap.put(beanType, r);
-    }
+    BeanPersistIds r = beanMap.computeIfAbsent(beanType, k -> new BeanPersistIds(desc));
     return r;
   }
 

src/main/java/io/ebeaninternal/server/transaction/BulkEventListenerMap.java

@@ -38,11 +38,7 @@ public class BulkEventListenerMap {
 
   private void register(String tableName, BulkTableEventListener l) {
     String upperTableName = tableName.trim().toUpperCase();
-    Entry entry = map.get(upperTableName);
-    if (entry == null) {
-      entry = new Entry();
-      map.put(upperTableName, entry);
-    }
+    Entry entry = map.computeIfAbsent(upperTableName, k -> new Entry());
     entry.add(l);
   }
 

src/main/java/io/ebeaninternal/server/transaction/DeleteByIdMap.java

@@ -68,11 +68,7 @@ public final class DeleteByIdMap {
 
   private BeanPersistIds getPersistIds(BeanDescriptor<?> desc) {
     String beanType = desc.getFullName();
-    BeanPersistIds r = beanMap.get(beanType);
-    if (r == null) {
-      r = new BeanPersistIds(desc);
-      beanMap.put(beanType, r);
-    }
+    BeanPersistIds r = beanMap.computeIfAbsent(beanType, k -> new BeanPersistIds(desc));
     return r;
   }
 

src/main/java/io/ebeaninternal/server/transaction/TransactionMap.java

@@ -4,6 +4,7 @@ import io.ebeaninternal.api.SpiTransaction;
 
 import javax.persistence.PersistenceException;
 import java.util.HashMap;
+import java.util.Map;
 
 
 /**
@@ -14,7 +15,7 @@ public class TransactionMap {
   /**
    * Map of State by serverName.
    */
-  private final HashMap<String, State> map = new HashMap<>();
+  private final Map<String, State> map = new HashMap<>();
 
   @Override
   public String toString() {
@@ -38,11 +39,7 @@ public class TransactionMap {
    */
   public State getStateWithCreate(String serverName) {
 
-    State state = map.get(serverName);
-    if (state == null) {
-      state = new State();
-      map.put(serverName, state);
-    }
+    State state = map.computeIfAbsent(serverName, k -> new State());
     return state;
   }