Converter実装

source/src/main/java/one/nem/lacerta/source/database/common/TagArrayListConverter.java

@@ -0,0 +1,28 @@
+package one.nem.lacerta.source.database.common;
+
+import androidx.room.TypeConverter;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+
+public class TagArrayListConverter {
+
+    @TypeConverter
+    public static ArrayList<String> fromString(String value) {
+        return value == null ? null : new ArrayList<String>(Arrays.asList(value.split(",")));
+    }
+
+    @TypeConverter
+    public static String fromArrayList(ArrayList<String> list) {
+        if (list == null) {
+            return null;
+        }
+
+        StringBuilder sb = new StringBuilder();
+        for (String s : list) {
+            sb.append(s);
+            sb.append(",");
+        }
+        return sb.toString();
+    }
+}