我想使用executors加速将可用数据列表导入数据库
public static void main(String[] args) {
methodOpenDatabaseConnection();
ExecutorService newFixedThreadPool = Executors.newScheduledThreadPool(100);
for (long i = 0; i < 1000; i++) {
newFixedThreadPool.execute(new Runnable() {
@Override
public void run( {
methodSaveDataToDatabaseMysql();
}
});
}
newFixedThreadPool.shutdown();
newFixedThreadPool.shutdown();
newFixedThreadPool.awaitTermination(60, TimeUnit.SECONDS);
if (newFixedThreadPool.isShutdown()) {
methodCloseConnectionDatabase();
}
}
public void methodSaveDataToDatabaseMysql() {
try {
preparedStatement = connection.prepareStatement("INSERT INTO `demo`"
+ " (`name`,`name2`,`name3`) VALUES (?,?,?)");
preparedStatement.setString(1, "name1");
preparedStatement.setString(2, "name2");
preparedStatement.setString(3, "name3");
preparedStatement.executeUpdate();
} catch (SQLException ex) {
Logger.getLogger(WebsiteResourcesImpl1.class.getName()).log(Level.SEVERE, null, ex);
}
}
如果我在save方法中添加synchronized,它将生成一个错误。它将成功,但速度没有提高
java.sql.SQLException: No value specified for parameter 3
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:569)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:537)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:527)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:512)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:480)
at com.mysql.cj.jdbc.PreparedStatement.checkAllParametersSet(PreparedStatement.java:2159)
我认为save语句没有问题,因为它仍然可以成功地保存数据,但在executorservice中不稳定
1条答案
按热度按时间jei2mxaa1#
基于此代码
preparedStatement = connection.prepareStatement...
那么preparedStatement
不是线程安全的。考虑让它成为当地的
methodSaveDataToDatabaseMysql
方法