Fixes nullpointer avoiding unnecessary .toString()

fixes #2

Author: ivangsa

src/main/java/io/zenwave360/jsonrefparser/$RefParser.java

@@ -139,7 +139,7 @@ public class $RefParser {
     }
 
     private void mergeAllOf(Object value, String[] paths, URI currentFileURL) {
-//        var visitedNodeRef = String.format("%s%s", currentFileURL.toString(), jsonPointer(paths));
+//        var visitedNodeRef = String.format("%s%s", currentFileURL, jsonPointer(paths));
 //        log.trace("{}visiting {}", indent(), visitedNodeRef);
 //        if(visited.contains(value)) {
 //            log.trace("{}skipping visited {}", indent(), visitedNodeRef);
@@ -177,7 +177,7 @@ private void mergeAllOf(Object value, String[] paths, URI currentFileURL) {
                 refs.jsonContext.set(jsonPath, mergedAllOfObject);
                 refs.saveOriginalAllOf(mergedAllOfObject, allOf);
             } catch (Exception e){
-                log.error("Error setting jsonPath:{} in file:{}", jsonPath, currentFileURL.toString(), e);
+                log.error("Error setting jsonPath:{} in file:{}", jsonPath, currentFileURL, e);
                 throw e;
             }
         } else if(value instanceof Map) {
@@ -200,7 +200,7 @@ private String indent() {
         return StringUtils.join(indent, "");
     }
     private void dereference(ExtendedJsonContext jsonContext, Object value, String[] paths, URI currentFileURL) {
-        var visitedNodeRef = String.format("%s%s", currentFileURL.toString(), jsonPointer(paths));
+        var visitedNodeRef = String.format("%s%s", currentFileURL, jsonPointer(paths));
         log.trace("{}visiting {}", indent(), visitedNodeRef);
         if(visited.contains(visitedNodeRef)) {
             log.trace("{}skipping visited {}", indent(), visitedNodeRef);
@@ -244,7 +244,7 @@ private void dereference(ExtendedJsonContext jsonContext, Object value, String[]
             // dereference resolved
             var resolvedRefURL = ObjectUtils.firstNonNull($ref.getURI(), currentFileURL);
             var resolvedNodePaths = jsonPointerToPaths($ref.getPath());
-            var resolvedNodeRef =  String.format("%s%s", resolvedRefURL.toString(), $ref.getPath());
+            var resolvedNodeRef =  String.format("%s%s", resolvedRefURL, $ref.getPath());
             indent.add(" => ");
             log.trace("{}dereferencing resolved {}", indent(), resolvedNodeRef);
             dereference(jsonContext, resolved, resolvedNodePaths, resolvedRefURL);
@@ -256,7 +256,7 @@ private void dereference(ExtendedJsonContext jsonContext, Object value, String[]
                 this.refs.saveOriginalRef($ref, resolved);
                 jsonContext.set(innerJsonPath, resolved);
             }catch (Exception e){
-                log.error("Error setting jsonPath: {} in {}", innerJsonPath,  currentFileURL.toString(), e);
+                log.error("Error setting jsonPath: {} in {}", innerJsonPath,  currentFileURL, e);
                 throw e;
             }
         } else if(value instanceof Map) {

src/test/java/io/zenwave360/jsonrefparser/DereferenceJsonStringTest.java

@@ -0,0 +1,37 @@
+package io.zenwave360.jsonrefparser;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.IOException;
+
+public class DereferenceJsonStringTest {
+
+    @Test
+    public void testDereferenceJsonString() throws IOException {
+        String json = "{\n" +
+                "  \"$schema\": \"http://json-schema.org/draft-07/schema#\",\n" +
+                "  \"definitions\": {\n" +
+                "    \"appMethods\": {\n" +
+                "      \"about\": {\n" +
+                "        \"type\": \"string\"\n" +
+                "      },\n" +
+                "      \"author\": {\n" +
+                "        \"type\": \"string\"\n" +
+                "      }\n" +
+                "    }\n" +
+                "  },\n" +
+                "  \"type\": \"object\",\n" +
+                "  \"properties\": {\n" +
+                "    \"$ref\": \"#/definitions/appMethods\"\n" +
+                "  }\n" +
+                "}";
+        $RefParser parser = new $RefParser(json).parse();
+        $Refs refs = parser.dereference().getRefs();
+        Assert.assertEquals(1, refs.refs().size());
+        Assert.assertTrue(refs.paths("file").isEmpty());
+        Assert.assertFalse(refs.refs("#/").isEmpty());
+        Assert.assertTrue(refs.get("$.definitions.appMethods") != null);
+    }
+}