X-Git-Url: https://gerrit.simantics.org/r/gitweb?p=simantics%2Fplatform.git;a=blobdiff_plain;f=bundles%2Forg.simantics.db.layer0%2Fsrc%2Forg%2Fsimantics%2Fdb%2Flayer0%2Fvariable%2FStandardVariableBuilder.java;h=992e3e6990fba165c0fd6c6ca901a479b4521730;hp=b1af87f98490016490d0891087da8e5679946d47;hb=701fffa16a9aec0e0565da12bd5da5d372f6e612;hpb=0df63f38249cbbc584d3a130773680c309fb1f71

diff --git a/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/variable/StandardVariableBuilder.java b/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/variable/StandardVariableBuilder.java
index b1af87f98..992e3e699 100644
--- a/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/variable/StandardVariableBuilder.java
+++ b/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/variable/StandardVariableBuilder.java
@@ -6,14 +6,25 @@ import org.simantics.db.exception.DatabaseException;
 
 public class StandardVariableBuilder<Node> implements VariableBuilder<Node> {
 
-	@Override
-	public Variable buildChild(ReadGraph graph, Variable parent, VariableNode<Node> node, Resource child) {
-		return new StandardGraphChildVariable(parent, node, child);
-	}
-
-	@Override
-	public Variable buildProperty(ReadGraph graph, Variable parent, VariableNode<Node> node, Resource subject, Resource predicate) throws DatabaseException {
-		return new StandardGraphPropertyVariable(graph, parent, node, subject, predicate);
-	}
+    private static StandardVariableBuilder<?> INSTANCE = null;
+
+    private StandardVariableBuilder() {}
+
+    public static synchronized StandardVariableBuilder<?> get() {
+        if(INSTANCE == null) {
+            INSTANCE = new StandardVariableBuilder<>();
+        }
+        return INSTANCE;
+    }
+
+    @Override
+    public Variable buildChild(ReadGraph graph, Variable parent, VariableNode<Node> node, Resource child) {
+        return new StandardGraphChildVariable(parent, node, child);
+    }
+
+    @Override
+    public Variable buildProperty(ReadGraph graph, Variable parent, VariableNode<Node> node, Resource subject, Resource predicate) throws DatabaseException {
+        return new StandardGraphPropertyVariable(graph, parent, node, subject, predicate);
+    }
 
 }