<分区>
我正在编写一个统计插件，它在加入时从数据库中检索统计信息，将它们实现到 HashMap 中，并在退出时将这些新统计信息实现到数据库中，这样做的原因是没有与每秒打开连接相比滞后很多。
如果这意味着什么，我正在使用 MariaDB。
下面的 HashMap
public static HashMap<String, Integer> kills = new HashMap<String, Integer>();
public static HashMap<String, Integer> deaths = new HashMap<String, Integer>();
代码如下
@EventHandler
public void onDeath(PlayerDeathEvent event){
Player p = event.getEntity();
Player k = p.getKiller();
kills.put(k.getName(), kills.get(k.getName() + 1));
deaths.put(p.getName(), deaths.get(p.getName() + 1));
removeScoreboard(p);
setScoreboard(p);
removeScoreboard(k);
setScoreboard(k);
}
@EventHandler
public void onJoin(PlayerJoinEvent e){
OfflinePlayer p2 = e.getPlayer();
Player p = e.getPlayer();
openConnection();
try{
int previousDeaths = 0;
int previousKills = 0;
if(playerDataContainsPlayer(p)){
PreparedStatement sql = connection.prepareStatement("SELECT deaths FROM `player_data` WHERE player=?;");
PreparedStatement sql2 = connection.prepareStatement("SELECT kills FROM `player_data` WHERE player=?;");
ResultSet result = sql.executeQuery();
ResultSet result2 = sql2.executeQuery();
result2.next();
result.next();
previousDeaths = result.getInt("deaths");
previousKills = result2.getInt("kills");
kills.put(p.getName(), previousKills);
deaths.put(p.getName(), previousDeaths);
sql.close();
sql2.close();
result.close();
result2.close();
removeScoreboard(p);
setScoreboard(p);
} else {
PreparedStatement newPlayer = connection.prepareStatement("INSERT INTO `player_data` values(?,0,0);");
newPlayer.setString(1, p.getUniqueId().toString());
newPlayer.setInt(2, 0);
newPlayer.setInt(3, 0);
newPlayer.execute();
newPlayer.close();
kills.put(p.getName(), 0);
deaths.put(p.getName(), 0);
removeScoreboard(p);
setScoreboard(p);
}
}catch(Exception e1){
e1.printStackTrace();
} finally{
closeConnection();
}
}
@EventHandler
public void onLeave(PlayerQuitEvent e){
Player p = e.getPlayer();
openConnection();
try{
int previousDeaths = 0;
int previousKills = 0;
if(playerDataContainsPlayer(p)){
PreparedStatement sql = connection.prepareStatement("SELECT deaths FROM `player_data` WHERE player=?;");
PreparedStatement sql2 = connection.prepareStatement("SELECT kills FROM `player_data` WHERE player=?;");
sql.setString(1, p.getUniqueId().toString());
sql2.setString(1, p.getUniqueId().toString());
ResultSet result = sql.executeQuery();
ResultSet result2 = sql2.executeQuery();
result2.next();
result.next();
previousDeaths = result.getInt("deaths");
previousKills = result2.getInt("kills");
PreparedStatement killsUpdate = connection.prepareStatement("UPDATE `player_data` SET kills=? WHERE player=?;");
killsUpdate.setInt(1, kills.get(p.getName()));
killsUpdate.setString(2, p.getUniqueId().toString());
killsUpdate.executeUpdate();
PreparedStatement deathsUpdate = connection.prepareStatement("UPDATE `player_data` SET deaths=? WHERE player=?;");
deathsUpdate.setInt(1, deaths.get(p.getName()));
deathsUpdate.setString(2, p.getUniqueId().toString());
deathsUpdate.executeUpdate();
deathsUpdate.close();
killsUpdate.close();
sql.close();
sql2.close();
result.close();
result2.close();
}
}catch(Exception e1){
e1.printStackTrace();
} finally{
closeConnection();
}
}
无论何时加入，它都会显示 [20:51:43 WARN]: java.sql.SQLException: No value specified for parameter 1
无论何时你杀了人，或者死了，你的杀戮都是空的，你的死亡也是空的。我不确定为什么会这样，感谢您的帮助。