HBX-3188: Improve the implementation of classes AbstractStrategy, OverrideBinder and SQLTypeMapping

Signed-off-by: Koen Aers <koen.aers@gmail.com>

Author: koentsje

orm/src/main/java/org/hibernate/tool/internal/reveng/strategy/AbstractStrategy.java

@@ -29,7 +29,7 @@ public abstract class AbstractStrategy implements RevengStrategy {
 
 	static final private Logger log = Logger.getLogger(AbstractStrategy.class);
 
-	private static Set<String> AUTO_OPTIMISTICLOCK_COLUMNS;
+	private static final Set<String> AUTO_OPTIMISTICLOCK_COLUMNS;
 
 	private RevengSettings settings = new RevengSettings(this);
 
@@ -145,7 +145,7 @@ public String tableToClassName(TableIdentifier tableIdentifier) {
 		String pkgName = settings.getDefaultPackageName();
 		String className = toUpperCamelCase( tableIdentifier.getName() );
 
-		if(pkgName.length()>0) {			
+		if(!pkgName.isEmpty()) {
 			return StringHelper.qualify(pkgName, className);
 		}
 		else {
@@ -187,7 +187,7 @@ public String getOptimisticLockColumnName(TableIdentifier identifier) {
 
 	public boolean useColumnForOptimisticLock(TableIdentifier identifier, String column) {
 		if(settings.getDetectOptimsticLock()) {
-			return AUTO_OPTIMISTICLOCK_COLUMNS.contains(column.toLowerCase())?true:false;
+			return AUTO_OPTIMISTICLOCK_COLUMNS.contains(column.toLowerCase());
 		} else {
 			return false;
 		}
@@ -221,11 +221,7 @@ public boolean isForeignKeyCollectionInverse(String name, Table foreignKeyTable,
 		       // if the reference column is the first one then we are inverse.
 			   Column column = foreignKeyTable.getColumn(0);
 			   Column fkColumn = (Column) referencedColumns.get(0);
-			   if(fkColumn.equals(column)) {
-				   return true;   
-			   } else {
-				   return false;
-			   }
+            return fkColumn.equals(column);
 		}
 		return true;
 	}
@@ -242,26 +238,23 @@ public boolean isOneToOne(ForeignKey foreignKey) {
 		if(settings.getDetectOneToOne()) {
 			// add support for non-PK associations
 			List<Column> fkColumns = foreignKey.getColumns();
-			List<Column> pkForeignTableColumns = null;
-			
+			List<Column> pkForeignTableColumns = Collections.emptyList();
+
 			if (foreignKey.getTable().hasPrimaryKey())
 				pkForeignTableColumns = foreignKey.getTable().getPrimaryKey().getColumns();
 
-			boolean equals =
-				fkColumns != null && pkForeignTableColumns != null
-				&& fkColumns.size() == pkForeignTableColumns.size();
+			boolean equals = fkColumns.size() == pkForeignTableColumns.size();
 
 			Iterator<Column> columns = foreignKey.getColumns().iterator();
 			while (equals && columns.hasNext()) {
-				Column fkColumn = (Column) columns.next();
-				equals = equals && pkForeignTableColumns.contains(fkColumn);
+				Column fkColumn = columns.next();
+				equals = pkForeignTableColumns.contains(fkColumn);
 			}
-
 			return equals;
 		} else {
 			return false;
 		}
-    }
+	}
 
 	public boolean isManyToManyTable(Table table) {
 		if(settings.getDetectManyToMany()) {
@@ -287,14 +280,11 @@ public boolean isManyToManyTable(Table table) {
 			}
 
 			// tests that all columns are implied in the fks
-			Set<Column> columns = new HashSet<Column>();
-			for (Column column : table.getColumns()) {
-				columns.add(column);
-			}
+            Set<Column> columns = new HashSet<>(table.getColumns());
 
 			for (ForeignKey fkey : table.getForeignKeys().values()) {
 				if (columns.isEmpty()) break;
-				columns.removeAll(fkey.getColumns());
+				fkey.getColumns().forEach(columns::remove);
 			}
 
 			return columns.isEmpty();