Save player logout times on shutdown (#3157)

Properly save userdata and mark the player's last logout time when the server is shutting down.

Fixes #2764.

Essentials/src/com/earth2me/essentials/Essentials.java

@@ -18,6 +18,7 @@
 package com.earth2me.essentials;
 
 import com.earth2me.essentials.commands.*;
+import com.earth2me.essentials.craftbukkit.ServerState;
 import com.earth2me.essentials.items.AbstractItemDb;
 import com.earth2me.essentials.items.CustomItemResolver;
 import com.earth2me.essentials.items.FlatItemDb;
@@ -367,7 +368,15 @@ public class Essentials extends JavaPlugin implements net.ess3.api.IEssentials {
                 user.setVanished(false);
                 user.sendMessage(tl("unvanishedReload"));
             }
-            user.stopTransaction();
+            if (ServerState.isStopping()) {
+                user.setLastLocation();
+                if (!user.isHidden()) {
+                    user.setLastLogout(System.currentTimeMillis());
+                }
+                user.cleanup();
+            } else {
+                user.stopTransaction();
+            }
         }
         cleanupOpenInventories();
         if (i18n != null) {

Essentials/src/com/earth2me/essentials/craftbukkit/ServerState.java

@@ -0,0 +1,66 @@
+package com.earth2me.essentials.craftbukkit;
+
+import net.ess3.nms.refl.ReflUtil;
+import org.bukkit.Bukkit;
+
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodType;
+
+public class ServerState {
+
+    private static final MethodHandle isStopping; //Only in Paper
+    private static final MethodHandle nmsHasStopped;
+    private static final MethodHandle nmsIsRunning;
+    private static final Object nmsServer;
+
+    static {
+        MethodHandle isStoppingHandle = null;
+        MethodHandle nmsHasStoppedHandle = null;
+        MethodHandle nmsIsRunningHandle = null;
+        Object nmsServerObject = null;
+        try {
+            isStoppingHandle = MethodHandles.lookup().findStatic(Bukkit.class, "isStopping", MethodType.methodType(boolean.class));
+        } catch (Throwable e) {
+            try {
+                Class<?> nmsClass = ReflUtil.getNMSClass("MinecraftServer");
+                if (nmsClass != null) {
+                    nmsServerObject = ReflUtil.getMethodCached(nmsClass, "getServer").invoke(null);
+                    nmsIsRunningHandle = MethodHandles.lookup().findVirtual(nmsClass, "isRunning", MethodType.methodType(boolean.class));
+                    nmsHasStoppedHandle = MethodHandles.lookup().findVirtual(nmsClass, "hasStopped", MethodType.methodType(boolean.class));
+                }
+            } catch (Throwable ignored) {
+            }
+        }
+        isStopping = isStoppingHandle;
+        nmsHasStopped = nmsHasStoppedHandle;
+        nmsIsRunning = nmsIsRunningHandle;
+        nmsServer = nmsServerObject;
+    }
+
+    public static boolean isStopping() {
+        boolean stopping = false;
+        if (isStopping != null) {
+            try {
+                stopping = (boolean) isStopping.invoke();
+            } catch (Throwable t) {
+                t.printStackTrace();
+            }
+        } else if (nmsServer != null) {
+            if (nmsHasStopped != null) {
+                try {
+                    stopping = (boolean) nmsHasStopped.invokeExact(nmsServer);
+                } catch (Throwable t) {
+                    t.printStackTrace();
+                }
+            } else if (nmsIsRunning != null) {
+                try {
+                    stopping = (boolean) nmsIsRunning.invokeExact(nmsServer);
+                } catch (Throwable t) {
+                    t.printStackTrace();
+                }
+            }
+        }
+        return stopping;
+    }
+}