3 files changed, 132 insertions, 0 deletions
diff --git a/src/com/p4square/grow/provider/JsonEncodedProvider.java b/src/com/p4square/grow/provider/JsonEncodedProvider.java
new file mode 100644
index 0000000..605b18c
--- /dev/null
+++ b/src/com/p4square/grow/provider/JsonEncodedProvider.java
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.provider;
+
+import java.io.IOException;
+
+import org.codehaus.jackson.map.DeserializationConfig;
+import org.codehaus.jackson.map.ObjectMapper;
+import org.codehaus.jackson.map.SerializationConfig;
+
+/**
+ * Provider provides a simple interface for loading and persisting
+ * objects.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public abstract class JsonEncodedProvider<K, V> implements Provider<K, V> {
+    public static final ObjectMapper MAPPER = new ObjectMapper();
+    static {
+        MAPPER.configure(SerializationConfig.Feature.WRITE_ENUMS_USING_TO_STRING, true);
+        MAPPER.configure(DeserializationConfig.Feature.READ_ENUMS_USING_TO_STRING, true);
+        MAPPER.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+    }
+
+    private final Class<V> mClazz;
+
+    public JsonEncodedProvider(Class<V> clazz) {
+        mClazz = clazz;
+    }
+
+    /**
+     * 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 {
+        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;
+        }
+
+        V obj = MAPPER.readValue(blob, mClazz);
+        return obj;
+    }
+}
+
diff --git a/src/com/p4square/grow/provider/Provider.java b/src/com/p4square/grow/provider/Provider.java
new file mode 100644
index 0000000..ca6af25
--- /dev/null
+++ b/src/com/p4square/grow/provider/Provider.java
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.provider;
+
+import java.io.IOException;
+
+/**
+ * Provider provides a simple interface for loading and persisting
+ * objects.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public interface Provider<K, V> {
+    /**
+     * Retrieve the object with the given key.
+     *
+     * @param key The key for the object.
+     * @return The object or null if not found.
+     */
+    V get(K key) throws IOException;
+
+    /**
+     * Persist the object with the given key.
+     *
+     * @param key The key for the object.
+     * @param obj The object to persist.
+     */
+    void put(K key, V obj) throws IOException;
+}
diff --git a/src/com/p4square/grow/provider/QuestionProvider.java b/src/com/p4square/grow/provider/QuestionProvider.java
new file mode 100644
index 0000000..b569dc8
--- /dev/null
+++ b/src/com/p4square/grow/provider/QuestionProvider.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2013 Jesse Morgan
+ */
+
+package com.p4square.grow.provider;
+
+import java.io.IOException;
+
+import com.p4square.grow.model.Question;
+
+/**
+ * QuestionProvider wraps an existing Provider to get and put Questions.
+ *
+ * @author Jesse Morgan <jesse@jesterpm.net>
+ */
+public abstract class QuestionProvider<K> implements Provider<String, Question> {
+
+    private Provider<K, Question> mProvider;
+
+    public QuestionProvider(Provider<K, Question> provider) {
+        mProvider = provider;
+    }
+
+    @Override
+    public Question get(String key) throws IOException {
+        return mProvider.get(makeKey(key));
+    }
+
+    @Override
+    public void put(String key, Question obj) throws IOException {
+        mProvider.put(makeKey(key), obj);
+    }
+
+    /**
+     * Make a Key for questionId.
+     *
+     * @param questionId The question id.
+     * @return a key for questionId.
+     */
+    protected abstract K makeKey(String questionId);
+}