From 8c037fc1a3eda05d7d8264f3f589d8aca7569270 Mon Sep 17 00:00:00 2001
From: tastybento <tastybento@wasteofplastic.com>
Date: Mon, 30 Sep 2019 15:38:00 -0700
Subject: [PATCH] Shifted GSON conversion to main thread to avoid concurrent
 modification

https://github.com/BentoBoxWorld/BentoBox/issues/968
---
 .../bentobox/bentobox/database/sql/SQLDatabaseHandler.java | 7 +++----
 .../database/sql/sqlite/SQLiteDatabaseHandler.java         | 6 +++---
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/main/java/world/bentobox/bentobox/database/sql/SQLDatabaseHandler.java b/src/main/java/world/bentobox/bentobox/database/sql/SQLDatabaseHandler.java
index 180cba593..8efb6f85d 100644
--- a/src/main/java/world/bentobox/bentobox/database/sql/SQLDatabaseHandler.java
+++ b/src/main/java/world/bentobox/bentobox/database/sql/SQLDatabaseHandler.java
@@ -155,17 +155,16 @@ public class SQLDatabaseHandler<T> extends AbstractJSONDatabaseHandler<T> {
             return;
         }
         // Async
-        processQueue.add(() -> store(instance, sqlConfig.getSaveObjectSQL()));
+        processQueue.add(() -> store(instance.getClass().getName(), getGson().toJson(instance), sqlConfig.getSaveObjectSQL()));
     }
 
-    private void store(T instance, String sb) {
-        String toStore = getGson().toJson(instance);
+    private void store(String name, String toStore, String sb) {
         try (PreparedStatement preparedStatement = connection.prepareStatement(sb)) {
             preparedStatement.setString(1, toStore);
             preparedStatement.setString(2, toStore);
             preparedStatement.execute();
         } catch (SQLException e) {
-            plugin.logError("Could not save object " + instance.getClass().getName() + " " + e.getMessage());
+            plugin.logError("Could not save object " + name + " " + e.getMessage());
         }
     }
 
diff --git a/src/main/java/world/bentobox/bentobox/database/sql/sqlite/SQLiteDatabaseHandler.java b/src/main/java/world/bentobox/bentobox/database/sql/sqlite/SQLiteDatabaseHandler.java
index cf8063e76..efa3a3ac5 100644
--- a/src/main/java/world/bentobox/bentobox/database/sql/sqlite/SQLiteDatabaseHandler.java
+++ b/src/main/java/world/bentobox/bentobox/database/sql/sqlite/SQLiteDatabaseHandler.java
@@ -49,9 +49,9 @@ public class SQLiteDatabaseHandler<T> extends SQLDatabaseHandler<T> {
             plugin.logError("This class is not a DataObject: " + instance.getClass().getName());
             return;
         }
-        processQueue.add(() -> {
-            Gson gson = getGson();
-            String toStore = gson.toJson(instance);
+        Gson gson = getGson();
+        String toStore = gson.toJson(instance);
+        processQueue.add(() -> {            
             try (PreparedStatement preparedStatement = getConnection().prepareStatement(getSqlConfig().getSaveObjectSQL())) {
                 preparedStatement.setString(1, toStore);
                 preparedStatement.setString(2, ((DataObject)instance).getUniqueId());