avoid the conversion to a map and go native

src/main/java/io/mapsmessaging/selector/resolvers/JsonEvaluator.java

@@ -1,10 +1,111 @@
 package io.mapsmessaging.selector.resolvers;
 
+import io.mapsmessaging.selector.IdentifierMutator;
+import org.json.JSONArray;
 import org.json.JSONObject;
 
-public class JsonEvaluator extends MapEvaluator {
+import java.math.BigDecimal;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.StringTokenizer;
 
-  public JsonEvaluator(JSONObject bean){
-    super(bean.toMap());
+public class JsonEvaluator implements IdentifierMutator {
+
+  private final JSONObject jsonObject;
+
+  public JsonEvaluator(JSONObject jsonObject){
+    this.jsonObject = jsonObject;
+  }
+
+
+  @Override
+  public Object get(String key) {
+    String[] keyPath = getKeyPath(key);
+    Object lookup = locateObject(jsonObject, keyPath);
+    return parseJSON(lookup);
+  }
+
+  @Override
+  public Object remove(String key) {
+    return get(key);
+  }
+
+  @Override
+  public Object set(String key, Object value) {
+    return false;
   }
+
+  private String[] getKeyPath(String key){
+    String[] keyPath;
+    if(key.contains(".")){
+      var stringTokenizer = new StringTokenizer(key, ".");
+      List<String> tmp = new ArrayList<>();
+      while(stringTokenizer.hasMoreElements()){
+        tmp.add(stringTokenizer.nextElement().toString());
+      }
+      var tmpPath = new String[tmp.size()];
+      keyPath = tmp.toArray(tmpPath);
+    }
+    else{
+      keyPath = new String[1];
+      keyPath[0] = key;
+    }
+    return keyPath;
+  }
+
+  private static  Object locateObject(JSONObject json, String[] searchPath){
+    if(searchPath != null){
+      // Walk the JSON path first
+      for(var x=0;x<searchPath.length;x++){
+        var path = searchPath[x];
+        var jsonLookup = json.get(path);
+        if(jsonLookup instanceof JSONArray){
+          var sub = new String[searchPath.length-(x +1)];
+          System.arraycopy(searchPath, x+1, sub, 0, sub.length);
+          return arrayLookup(json.getJSONArray(path), sub);
+        }
+        else if(jsonLookup instanceof JSONObject){
+          json = (JSONObject) jsonLookup;
+        }
+        else{
+          return jsonLookup;
+        }
+      }
+    }
+    return null;
+  }
+
+  private static Object arrayLookup(JSONArray array, String[] path){
+    // We have an array, so the next element in the path must be an index ( ie number)
+    var idx = Integer.parseInt(path[0]);
+    Object lookup = array.get(idx);
+    if(lookup instanceof JSONObject){
+      var sub = new String[path.length-1];
+      System.arraycopy(path, 1, sub, 0, sub.length);
+      return locateObject( (JSONObject) lookup, sub);
+    }
+    else if(lookup instanceof JSONArray){
+      var sub = new String[path.length-1];
+      System.arraycopy(path, 1, sub, 0, sub.length);
+      return arrayLookup( (JSONArray) lookup, sub);
+    }
+    return lookup;
+  }
+
+  private static Object parseJSON(Object lookup){
+    if (lookup instanceof String ||
+        lookup instanceof Float ||
+        lookup instanceof Double ||
+        lookup instanceof Byte ||
+        lookup instanceof Short ||
+        lookup instanceof Integer ||
+        lookup instanceof Long) {
+      return lookup;
+    }
+    else if(lookup instanceof BigDecimal){
+      return ((BigDecimal)lookup).doubleValue();
+    }
+    return null;
+  }
+
 }

src/test/java/io/mapsmessaging/selector/JsonFilteringTest.java

@@ -28,7 +28,39 @@ void simpleJsonFiltering() throws ParseException {
       }
     }
     Assertions.assertEquals(alaskaCount, filtered);
+  }
+
+
+  @Test
+  void nestedJsonFiltering() throws ParseException {
+    Faker faker = new Faker();
+    JSONArray addressList = buildList();
+    JSONArray people = new JSONArray();
+    for(int x=0;x<addressList.length();x++){
+      JSONObject address = addressList.getJSONObject(x);
+      JSONObject person = new JSONObject();
+      person.put("address", address);
+      person.put("first", faker.name().firstName());
+      person.put("last", faker.name().lastName());
+      person.put("phone", faker.phoneNumber().phoneNumber());
+      person.put("email", faker.internet().emailAddress());
+      people.put(person);
+    }
+
 
+    int alaskaCount = 0;
+    int filtered = 0;
+    ParserExecutor executor = SelectorParser.compile("address.state = 'Alaska'");
+    for(int x=0;x<people.length();x++){
+      JSONObject person = people.getJSONObject(x);
+      if(person.getJSONObject("address").get("state").equals("Alaska")){
+        alaskaCount++;
+      }
+      if(executor.evaluate(person)){
+        filtered++;
+      }
+    }
+    Assertions.assertEquals(alaskaCount, filtered);
   }