HHH-6174 Allowing of creation of ObjectName from single string

hibernate-core/src/main/java/org/hibernate/metamodel/relational/ObjectName.java

@@ -23,6 +23,8 @@
  */
 package org.hibernate.metamodel.relational;
 
+import org.hibernate.HibernateException;
+
 /**
  * Models the qualified name of a database object.
  * <p/>
@@ -33,6 +35,9 @@ package org.hibernate.metamodel.relational;
  * @author Steve Ebersole
  */
 public class ObjectName {
+	// todo - should depend on DatabaseMetaData. For now hard coded (HF)
+	private static String SEPARATOR = ".";
+
 	private final Identifier schema;
 	private final Identifier catalog;
 	private final Identifier name;
@@ -40,6 +45,19 @@ public class ObjectName {
 	private final String identifier;
 	private final int hashCode;
 
+	/**
+	 * Tries to create an {@code ObjectName} from a name.
+	 *
+	 * @param objectName simple or qualified name of the database object.
+	 */
+	public ObjectName(String objectName) {
+		this(
+				extractSchema( objectName ),
+				extractCatalog( objectName ),
+				extractName( objectName )
+		);
+	}
+
 	public ObjectName(Identifier name) {
 		this( null, null, name );
 	}
@@ -123,12 +141,6 @@ public class ObjectName {
 				&& areEqual( schema, that.schema );
 	}
 
-	private boolean areEqual(Identifier one, Identifier other) {
-		return one == null
-				? other == null
-				: one.equals( other );
-	}
-
 	@Override
 	public int hashCode() {
 		return hashCode;
@@ -143,5 +155,64 @@ public class ObjectName {
 				", catalog='" + catalog + '\'' +
 				'}';
 	}
+
+	private boolean areEqual(Identifier one, Identifier other) {
+		return one == null
+				? other == null
+				: one.equals( other );
+	}
+
+	private static String extractSchema(String qualifiedName) {
+		if ( qualifiedName == null ) {
+			return null;
+		}
+		String[] tokens = qualifiedName.split( SEPARATOR );
+		if ( tokens.length == 0 || tokens.length == 1 ) {
+			return null;
+		}
+		else if ( tokens.length == 2 ) {
+			// todo - this case needs to be refined w/ help of  DatabaseMetaData (HF)
+			return null;
+		}
+		else if ( tokens.length == 3 ) {
+			return tokens[0];
+		}
+		else {
+			throw new HibernateException( "Unable to parse object name: " + qualifiedName );
+		}
+	}
+
+	private static String extractCatalog(String qualifiedName) {
+		if ( qualifiedName == null ) {
+			return null;
+		}
+		String[] tokens = qualifiedName.split( SEPARATOR );
+		if ( tokens.length == 0 || tokens.length == 1 ) {
+			return null;
+		}
+		else if ( tokens.length == 2 ) {
+			// todo - this case needs to be refined w/ help of  DatabaseMetaData (HF)
+			return null;
+		}
+		else if ( tokens.length == 3 ) {
+			return tokens[1];
+		}
+		else {
+			throw new HibernateException( "Unable to parse object name: " + qualifiedName );
+		}
+	}
+
+	private static String extractName(String qualifiedName) {
+		if ( qualifiedName == null ) {
+			return null;
+		}
+		String[] tokens = qualifiedName.split( SEPARATOR );
+		if ( tokens.length == 0 ) {
+			return qualifiedName;
+		}
+		else {
+			return tokens[tokens.length - 1];
+		}
+	}
 }