Design serialization format

JSON

main/src/main/java/sd/serialization/JsonMessageSerializer.java

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+package sd.serialization;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonSyntaxException;
+
+import java.nio.charset.StandardCharsets;
+
+/**
+ * JSON-based implementation of {@link MessageSerializer} using Google's Gson library.
+ * 
+ * This serializer converts objects to JSON format for transmission, providing:
+ * - Human-readable message format (easy debugging)
+ * - Cross-platform compatibility
+ * - Smaller message sizes compared to Java native serialization
+ * - Better security (no code execution during deserialization)
+ * 
+ * The serializer is configured with pretty printing disabled by default for
+ * production use, but can be enabled for debugging purposes.
+ * 
+ * Thread-safety: This class is thread-safe as Gson instances are thread-safe.
+ * 
+ * @see MessageSerializer
+ */
+public class JsonMessageSerializer implements MessageSerializer {
+    
+    private final Gson gson;
+    private final boolean prettyPrint;
+    
+    /**
+     * Creates a new JSON serializer with default configuration (no pretty printing).
+     */
+    public JsonMessageSerializer() {
+        this(false);
+    }
+    
+    /**
+     * Creates a new JSON serializer with optional pretty printing.
+     * 
+     * @param prettyPrint If true, JSON output will be formatted with indentation
+     */
+    public JsonMessageSerializer(boolean prettyPrint) {
+        this.prettyPrint = prettyPrint;
+        GsonBuilder builder = new GsonBuilder();
+        
+        if (prettyPrint) {
+            builder.setPrettyPrinting();
+        }
+        
+        // Register custom type adapters here if needed
+        // builder.registerTypeAdapter(Vehicle.class, new VehicleAdapter());
+        
+        this.gson = builder.create();
+    }
+    
+    @Override
+    public byte[] serialize(Object object) throws SerializationException {
+        if (object == null) {
+            throw new IllegalArgumentException("Cannot serialize null object");
+        }
+        
+        try {
+            String json = gson.toJson(object);
+            return json.getBytes(StandardCharsets.UTF_8);
+        } catch (Exception e) {
+            throw new SerializationException(
+                "Failed to serialize object of type " + object.getClass().getName(), e);
+        }
+    }
+    
+    @Override
+    public <T> T deserialize(byte[] data, Class<T> clazz) throws SerializationException {
+        if (data == null) {
+            throw new IllegalArgumentException("Cannot deserialize null data");
+        }
+        if (clazz == null) {
+            throw new IllegalArgumentException("Class type cannot be null");
+        }
+        
+        try {
+            String json = new String(data, StandardCharsets.UTF_8);
+            return gson.fromJson(json, clazz);
+        } catch (JsonSyntaxException e) {
+            throw new SerializationException(
+                "Failed to parse JSON for type " + clazz.getName(), e);
+        } catch (Exception e) {
+            throw new SerializationException(
+                "Failed to deserialize object of type " + clazz.getName(), e);
+        }
+    }
+    
+    @Override
+    public String getName() {
+        return "JSON (Gson)";
+    }
+    
+    /**
+     * Returns the underlying Gson instance for advanced usage.
+     * 
+     * @return The Gson instance
+     */
+    public Gson getGson() {
+        return gson;
+    }
+    
+    /**
+     * Checks if pretty printing is enabled.
+     * 
+     * @return true if pretty printing is enabled
+     */
+    public boolean isPrettyPrint() {
+        return prettyPrint;
+    }
+}