1 files changed, 83 insertions, 0 deletions
diff --git a/src/main/java/com/p4square/grow/provider/JsonEncodedProvider.java b/src/main/java/com/p4square/grow/provider/JsonEncodedProvider.java
new file mode 100644
index 0000000..500f761
--- /dev/null
+++ b/src/main/java/com/p4square/grow/provider/JsonEncodedProvider.java
@@ -0,0 +1,83 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.provider;
+
+import java.io.IOException;
+
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.JavaType;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+
+/**
+ * Provider provides a simple interface for loading and persisting
+ * objects.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public abstract class JsonEncodedProvider<V> {
+    public static final ObjectMapper MAPPER = new ObjectMapper();
+    static {
+        MAPPER.configure(SerializationFeature.WRITE_ENUMS_USING_TO_STRING, true);
+        MAPPER.configure(DeserializationFeature.READ_ENUMS_USING_TO_STRING, true);
+        MAPPER.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+    }
+
+    protected final Class<V> mClazz;
+    protected final JavaType mType;
+
+    public JsonEncodedProvider(Class<V> clazz) {
+        mClazz = clazz;
+        mType = null;
+    }
+
+    public JsonEncodedProvider(JavaType type) {
+        mType = type;
+        mClazz = null;
+    }
+
+    /**
+     * Encode the object as JSON.
+     *
+     * @param obj The object to encode.
+     * @return The JSON encoding of obj.
+     * @throws IOException if the object cannot be encoded.
+     */
+    protected String encode(V obj) throws IOException {
+        if (mClazz == String.class) {
+            return (String) obj;
+        }
+
+        return MAPPER.writeValueAsString(obj);
+    }
+
+    /**
+     * Decode the JSON string as an object.
+     *
+     * @param blob The JSON data to decode.
+     * @return The decoded object or null if blob is null.
+     * @throws IOException If an object cannot be decoded.
+     */
+    protected V decode(String blob) throws IOException {
+        if (blob == null) {
+            return null;
+        }
+
+        if (mClazz == String.class) {
+            return (V) blob;
+        }
+
+        V obj;
+        if (mClazz != null) {
+            obj = MAPPER.readValue(blob, mClazz);
+
+        } else {
+            obj = MAPPER.readValue(blob, mType);
+        }
+
+        return obj;
+    }
+}
+