Updated JSONObjectOutputStream to support extended generics

Zutil.iml

@@ -32,5 +32,15 @@
         <jarDirectory url="file://$MODULE_DIR$/libs" recursive="false" type="SOURCES" />
       </library>
     </orderEntry>
+    <orderEntry type="module-library" scope="TEST">
+      <library name="JUnit4">
+        <CLASSES>
+          <root url="jar://$APPLICATION_HOME_DIR$/lib/junit-4.12.jar!/" />
+          <root url="jar://$APPLICATION_HOME_DIR$/lib/hamcrest-core-1.3.jar!/" />
+        </CLASSES>
+        <JAVADOC />
+        <SOURCES />
+      </library>
+    </orderEntry>
   </component>
 </module>

src/zutil/ClassUtil.java

@@ -27,8 +27,11 @@ package zutil;
 import java.lang.reflect.Field;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
+import java.lang.reflect.TypeVariable;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashSet;
+import java.util.Objects;
 
 /**
  * This class include some utility functions for classes
@@ -83,15 +86,42 @@ public class ClassUtil {
     }
 
 
+    /**
+     * @param   field       is the field to return the generics from
+     * @return the generics assigned to a specific field or a empty list
+     */
     public static Class<?>[] getGenericClasses(Field field){
-        Class[] classArray = new Class[0];
+        return getGenericClasses(field.getGenericType());
-        Type genericFieldType = field.getGenericType();
+    }
+    /**
+     * Traverses the class hierarchy and searches for the given super class or interface
+     * and returns the assigned generic types.
+     *
+     * @param   c               the source class
+     * @param   superClass      is the super class to search for
+     * @return the generics for a specific super class or a empty list if
+     *         there is no generics or the super class is not found
+     */
+    public static Class<?>[] getGenericClasses(Class<?> c, Class<?> superClass){
+        // Search for the super class
+        while (c.getSuperclass() != Object.class && !superClass.isAssignableFrom(c.getSuperclass()))
+            c = c.getSuperclass();
+        // Did we find the super class?
+        if (superClass.isAssignableFrom(c.getSuperclass()))
+            return getGenericClasses(c.getGenericSuperclass());
 
-        if(genericFieldType instanceof ParameterizedType){
+        return new Class[0];
-            ParameterizedType aType = (ParameterizedType) genericFieldType;
+    }
-            Type[] fieldArgTypes = aType.getActualTypeArguments();
+    private static Class<?>[] getGenericClasses(Type genericType){
-            classArray = Arrays.copyOf(fieldArgTypes, fieldArgTypes.length, Class[].class);
+        if(genericType instanceof ParameterizedType){
+            ParameterizedType aType = (ParameterizedType) genericType;
+            Type[] argTypes = aType.getActualTypeArguments();
+            Class<?>[] classArray = new Class<?>[argTypes.length];
+            for(int i=0; i<classArray.length; ++i) {
+                classArray[i] = (Class<?>) argTypes[i];
+            }
+            return classArray;
         }
-        return classArray;
+        return new Class[0];
     }
 }

src/zutil/parser/json/JSONObjectInputStream.java

@@ -129,8 +129,8 @@ public class JSONObjectInputStream extends InputStream implements ObjectInput, C
 
 
     @SuppressWarnings({ "rawtypes", "unchecked" })
-    protected Object readType(Class<?> type, Class<?>[] genType, String key, DataNode json) throws IllegalAccessException, ClassNotFoundException, InstantiationException, UnsupportedDataTypeException, NoSuchFieldException {
+    protected Object readType(Class<?> type, String key, DataNode json) throws IllegalAccessException, ClassNotFoundException, InstantiationException, UnsupportedDataTypeException, NoSuchFieldException {
-        if(json == null)
+        if(json == null || type == null)
             return null;
         // Field type is a primitive?
         if(type.isPrimitive() || String.class.isAssignableFrom(type)){
@@ -142,25 +142,27 @@ public class JSONObjectInputStream extends InputStream implements ObjectInput, C
             else{
                 Object array = Array.newInstance(type.getComponentType(), json.size());
                 for(int i=0; i<json.size(); i++){
-                    Array.set(array, i, readType(type.getComponentType(), null, key, json.get(i)));
+                    Array.set(array, i, readType(type.getComponentType(), key, json.get(i)));
                 }
                 return array;
             }
         }
         else if(List.class.isAssignableFrom(type)){
+            Class<?>[] genType = ClassUtil.getGenericClasses(type, List.class);
             List list = (List)type.newInstance();
             for(int i=0; i<json.size(); i++){
-                list.add(readType(genType[0], null, key, json.get(i)));
+                list.add(readType((genType.length>=1? genType[0] : null), key, json.get(i)));
             }
             return list;
         }
         else if(Map.class.isAssignableFrom(type)){
+            Class<?>[] genType = ClassUtil.getGenericClasses(type, Map.class);
             Map map = (Map)type.newInstance();
             for(Iterator<String> it=json.keyIterator(); it.hasNext();){
                 String subKey = it.next();
                 map.put(
                         subKey,
-                        readType(genType[1], null, subKey, json.get(subKey)));
+                        readType((genType.length>=2? genType[1] : null), subKey, json.get(subKey)));
             }
             return map;
         }
@@ -210,7 +212,6 @@ public class JSONObjectInputStream extends InputStream implements ObjectInput, C
                 field.setAccessible(true);
                 field.set(obj, readType(
                         field.getType(),
-                        ClassUtil.getGenericClasses(field),
                         field.getName(),
                         json.get(field.getName())));
             }