1 files changed, 56 insertions, 0 deletions
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/JWalk.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/JWalk.java
new file mode 100644
index 000000000..6f9c4cfa5
--- /dev/null
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/JWalk.java
@@ -0,0 +1,56 @@
+package org.sufficientlysecure.keychain.util;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+/**
+ * Minimal hierarchy selector
+ */
+public class JWalk {
+
+    public static int getInt(JSONObject json, String... path) throws JSONException {
+        json = walk(json, path);
+        return json.getInt(path[path.length - 1]);
+    }
+
+    public static long getLong(JSONObject json, String... path) throws JSONException {
+        json = walk(json, path);
+        return json.getLong(path[path.length - 1]);
+    }
+
+    public static String getString(JSONObject json, String... path) throws JSONException {
+        json = walk(json, path);
+        return json.getString(path[path.length - 1]);
+    }
+
+    public static JSONArray getArray(JSONObject json, String... path) throws JSONException {
+        json = walk(json, path);
+        return json.getJSONArray(path[path.length - 1]);
+    }
+
+    public static JSONObject optObject(JSONObject json, String... path) throws JSONException {
+        json = walk(json, path);
+        return json.optJSONObject(path[path.length - 1]);
+    }
+
+    private static JSONObject walk(JSONObject json, String... path) throws JSONException {
+        int len = path.length - 1;
+        int pathIndex = 0;
+        try {
+            while (pathIndex < len) {
+                json = json.getJSONObject(path[pathIndex]);
+                pathIndex++;
+            }
+        } catch (JSONException e) {
+            // try to give ’em a nice-looking error
+            StringBuilder sb = new StringBuilder();
+            for (int i = 0; i < len; i++) {
+                sb.append(path[i]).append('.');
+            }
+            sb.append(path[len]);
+            throw new JSONException("JWalk error at step " + pathIndex + " of " + sb);
+        }
+        return json;
+    }
+}