Version 2: Added support of Parsing Json String / List

& added operations on JsonArray / JsonObject

JsonArray.java

@@ -0,0 +1,77 @@
+package cn.colintree.aix.JsonUtils;
+
+import com.google.appinventor.components.runtime.ComponentContainer;
+import com.google.appinventor.components.runtime.util.YailList;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+/**
+ * A non visible container for JSONArray
+ *
+ */
+public final class JsonArray extends JsonType {
+
+    public static JsonArray parseJsonArray(YailList list) throws JSONException {
+        return new JsonArray(parseJSONArray(list));
+    }
+
+    public static JSONArray parseJSONArray(YailList list) throws JSONException {
+        if (JsonObject.canParseJSONObject(list)) {
+            throw new IllegalArgumentException();
+        }
+        int size = list.size();
+        JSONArray array = new JSONArray();
+        Object item;
+        for (int i = 0; i < size; i++) {
+            item = list.getObject(i);
+            array.put(item instanceof YailList
+                    ? JsonUtils.List2Json((YailList) item)
+                    : item);
+        }
+        return array;
+    }
+
+    private final JSONArray array;
+
+    JsonArray(ComponentContainer container) {
+        this(new JSONArray());
+    }
+    JsonArray(JSONArray array) {
+        super(null);
+        if (array == null) {
+            array = new JSONArray();
+        }
+        this.array = array;
+    }
+
+    @Override
+    public String toString() {
+        return array.toString();
+    }
+
+    public JSONArray getArray() {
+        return array;
+    }
+
+    @Override
+    public YailList toList() {
+        return toList(array);
+    }
+
+    public static YailList toList(JSONArray array) {
+        int length = array.length();
+        Object[] objs = new Object[length];
+        for (int i = 0; i < length; i++) {
+            objs[i] = array.opt(i);
+            if (objs[i] instanceof JSONArray) {
+                objs[i] = JsonArray.toList((JSONArray) objs[i]);
+            } else if (objs[i] instanceof JSONObject) {
+                objs[i] = JsonObject.toList((JSONObject) objs[i]);
+            }
+        }
+        return YailList.makeList(objs);
+    }
+
+}

JsonObject.java

@@ -0,0 +1,101 @@
+package cn.colintree.aix.JsonUtils;
+
+import java.util.Iterator;
+
+import com.google.appinventor.components.runtime.ComponentContainer;
+import com.google.appinventor.components.runtime.util.YailList;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+/**
+ * A non visible container for JSONObject
+ */
+public final class JsonObject extends JsonType {
+
+    public static JsonObject parseJsonObject(YailList list) throws JSONException {
+        return new JsonObject(parseJSONObject(list));
+    }
+
+    public static JSONObject parseJSONObject(YailList list) throws JSONException {
+        if (!canParseJSONObject(list)) {
+            throw new IllegalArgumentException();
+        }
+        int size = list.size();
+        JSONObject object = new JSONObject();
+        YailList itemList;
+        for (int i = 0; i < size; i++) {
+            itemList = (YailList) list.getObject(i);
+            object.put(
+                (String) itemList.getObject(0),
+                itemList.getObject(1) instanceof YailList
+                    ? JsonUtils.List2Json((YailList) itemList.getObject(1))
+                    : itemList.getObject(1)
+            );
+        }
+        return object;
+    }
+
+    public static boolean canParseJSONObject(YailList list) {
+        int size = list.size();
+        Object item;
+        for (int i = 0; i < size; i++) {
+            item = list.getObject(i);
+            if (item instanceof YailList && ((YailList)item).size() == 2
+                && ((YailList)item).getObject(0) instanceof String) {
+                // this item is a valid object item
+            } else {
+                return false;
+            }
+        }
+        return true;
+    }
+
+
+    private final JSONObject object;
+
+    JsonObject(ComponentContainer container) {
+        this(new JSONObject());
+    }
+    JsonObject(JSONObject object) {
+        super(null);
+        this.object = object;
+    }
+
+    @Override
+    public String toString() {
+        return object.toString();
+    }
+
+    public JSONObject getObject() {
+        return object;
+    }
+
+    @Override
+    public YailList toList() {
+        return toList(object);
+    }
+
+    public static YailList toList(JSONObject object) {
+        int length = object.length();
+        Object[] objs = new Object[length];
+        int i = 0;
+        String key;
+        Object value;
+        Iterator<String> iterator = object.keys();
+        while (iterator.hasNext()) {
+            key = iterator.next();
+            value = object.opt(key);
+            if (value instanceof JSONArray) {
+                value = JsonArray.toList((JSONArray) value);
+            } else if (value instanceof JSONObject) {
+                value = JsonObject.toList((JSONObject) value);
+            }
+            objs[i] = YailList.makeList(new Object[]{ key, value });
+            i++;
+        }
+        return YailList.makeList(objs);
+    }
+
+}

JsonType.java

@@ -0,0 +1,18 @@
+package cn.colintree.aix.JsonUtils;
+
+import com.google.appinventor.components.runtime.AndroidNonvisibleComponent;
+import com.google.appinventor.components.runtime.ComponentContainer;
+import com.google.appinventor.components.runtime.util.YailList;
+
+public abstract class JsonType extends AndroidNonvisibleComponent {
+
+    public JsonType(ComponentContainer container) {
+        super(null);
+    }
+
+    @Override
+    public abstract String toString();
+
+    public abstract YailList toList();
+
+}