diff --git a/jsprit-core/src/main/java/jsprit/core/problem/io/VrpJsonReader.java b/jsprit-core/src/main/java/jsprit/core/problem/io/VrpJsonReader.java
index eb838d4d..39457f8a 100644
--- a/jsprit-core/src/main/java/jsprit/core/problem/io/VrpJsonReader.java
+++ b/jsprit-core/src/main/java/jsprit/core/problem/io/VrpJsonReader.java
@@ -33,6 +33,7 @@ import jsprit.core.problem.vehicle.VehicleTypeImpl;
 import jsprit.core.util.Coordinate;
 
 import java.io.File;
+import java.io.FileReader;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -68,7 +69,7 @@ public class VrpJsonReader {
         parse(root);
     }
 
-    private void parse(JsonNode problemRoot) {
+    public void parse(JsonNode problemRoot) {
         setFleetSize(problemRoot);
         parse_and_map_vehicle_types(problemRoot);
         parse_vehicles(problemRoot);
@@ -91,7 +92,7 @@ public class VrpJsonReader {
         JsonNode node = null;
         try {
             ObjectMapper objectMapper = new ObjectMapper();
-            node = objectMapper.readTree(jsonFile).path(JsonConstants.PROBLEM);
+            node = objectMapper.readTree(new FileReader(jsonFile)).path(JsonConstants.PROBLEM);
         } catch (IOException e) {
             e.printStackTrace();
             System.exit(1);
diff --git a/jsprit-core/src/main/java/jsprit/core/problem/io/VrpJsonWriter.java b/jsprit-core/src/main/java/jsprit/core/problem/io/VrpJsonWriter.java
index f7fda2d8..91c42edd 100644
--- a/jsprit-core/src/main/java/jsprit/core/problem/io/VrpJsonWriter.java
+++ b/jsprit-core/src/main/java/jsprit/core/problem/io/VrpJsonWriter.java
@@ -72,6 +72,8 @@ public class VrpJsonWriter {
             JsonGenerator jsonGenerator = new JsonFactory().createGenerator(stringWriter);
             if(solution == null) writeProblem(jsonGenerator);
             else writeSolution(jsonGenerator);
+            jsonGenerator.flush();
+            jsonGenerator.close();
         } catch (IOException e) {
             e.printStackTrace();
             System.exit(1);