added timed thread, added batch, cleaned code

changed starting value to false

src/main/java/server/ExpLogger.java

@@ -0,0 +1,93 @@
+package server;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.Executors;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ThreadFactory;
+import java.sql.Timestamp;
+import static java.util.concurrent.TimeUnit.*;
+
+import config.YamlConfig;
+import tools.DatabaseConnection;
+
+public class ExpLogger {
+    private static final LinkedBlockingQueue<ExpLogRecord> expLoggerQueue = new LinkedBlockingQueue<>();
+    private static final short EXP_LOGGER_THREAD_SLEEP_DURATION_SECONDS = 60;
+    private static final short EXP_LOGGER_THREAD_SHUTDOWN_WAIT_DURATION_MINUTES = 5;
+
+    public record ExpLogRecord(int worldExpRate, int expCoupon, long gainedExp, int currentExp,Timestamp expGainTime, int charid) {}
+
+    public static void putExpLogRecord(ExpLogRecord expLogRecord) {
+        try {
+            expLoggerQueue.put(expLogRecord);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+
+    static private ScheduledExecutorService schdExctr = Executors.newSingleThreadScheduledExecutor(new ThreadFactory() {
+        @Override
+        public Thread newThread(Runnable r) {
+            Thread t = new Thread(r);
+            t.setPriority(Thread.MIN_PRIORITY);
+            return t;
+        }
+    });
+
+    private static Runnable saveExpLoggerToDBRunnable = new Runnable() {
+        @Override
+        public void run() {
+            try (Connection con = DatabaseConnection.getConnection();
+                    PreparedStatement ps = con.prepareStatement("INSERT INTO characterexplogs (world_exp_rate, exp_coupon, gained_exp, current_exp, exp_gain_time, charid) VALUES (?, ?, ?, ?, ?, ?)")) {
+
+                List<ExpLogRecord> drainedExpLogs = new ArrayList<>();
+                expLoggerQueue.drainTo(drainedExpLogs);
+                for (ExpLogRecord expLogRecord : drainedExpLogs) {
+                    ps.setInt(1, expLogRecord.worldExpRate);
+                    ps.setInt(2, expLogRecord.expCoupon);
+                    ps.setLong(3, expLogRecord.gainedExp);
+                    ps.setInt(4, expLogRecord.currentExp);
+                    ps.setTimestamp(5, expLogRecord.expGainTime);
+                    ps.setInt(6, expLogRecord.charid);
+                    ps.addBatch();
+                }
+                ps.executeBatch();
+            } catch (SQLException sqle) {
+                sqle.printStackTrace();
+            }
+        }
+    };
+
+
+    private static void startExpLogger() {
+        schdExctr.schedule(saveExpLoggerToDBRunnable, EXP_LOGGER_THREAD_SLEEP_DURATION_SECONDS, SECONDS);
+        Runtime.getRuntime().addShutdownHook(new Thread(() -> {
+           stopExpLogger();
+        }));
+    }
+
+    private static boolean stopExpLogger() {
+        schdExctr.shutdown();
+        try {
+            schdExctr.awaitTermination(EXP_LOGGER_THREAD_SHUTDOWN_WAIT_DURATION_MINUTES, MINUTES);
+            Thread runThreadBeforeShutdown = new Thread(saveExpLoggerToDBRunnable);
+            runThreadBeforeShutdown.setPriority(Thread.MIN_PRIORITY);
+            runThreadBeforeShutdown.start();
+            return true;
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+            return false;
+        }
+    }
+
+    static {
+        if (YamlConfig.config.server.USE_EXP_GAIN_LOG) {
+            startExpLogger();
+        }
+    }
+}