java - 使用语句和结果集管理多个查询可选查询

当前，我们有一个Java应用程序，它具有许多不同的查询，并且并不是所有的查询都在一个特定的时间运行。因此，对于每个查询，我们计划有一个新的语句和结果集并立即关闭它们？下面是我们现在如何运行查询的代码片段。我们试图用try and catch覆盖每个查询，但是如果查询失败，则问题将无法在全局级别上进行。最好的顶部如何放置它们以确保也没有内存泄漏？

try{ //main try outside

//lots of inner queries run based on some logics of if else etc


//sample query of opening and closing both statement and resultsets.

Statement stmt1 = null;
stmt1 = dbconn.createStatement();
String selectQuery1  = "Select query";
ResultSet rs1 = stmt1 .executeQuery(selectQuery1);
while(rs1.next()) {
//process here

}
try{
  if (rs1 != null ){
     rs1.close();
  }
  if (stmt1!= null ){
    stmt1.close()
  }
}
catch(SQLException ex){
ex.printStackTrace(System.out);
}

dbconn.commit();
}
catch (SQLException ex) {
 try {
   dbconn.rollback();
 }
 catch (Exception rollback){
  rollback.printStackTrace(System.out);
 }
}
catch (Exception e){
 try{
    dbconn.rollback();
 }
 catch (Exception rollback) {
   rollback.printStackTrace(System.out);
 }
}

最佳答案

为了使回滚起作用，必须首先检查autoCommit最初是否设置为false。您只想在所有操作都成功执行后才提交。

一种执行此方法的方法可能是使用如下结构：

Connection connection = getDBConnection(); //Depends on how you get your connection
boolean autoCommit = connection.getAutoCommit();
try{
    //Set autoCommit to false. You will manage commiting your transaction
    connection.setAutoCommit(false);
    //Perform your sql operation

    if(doCommit){ //all your ops have successfully executed, you can use a flag for this
        connection.commit();
    }
}catch(Exception exe){
    //Rollback
}finally{
    connection.setAutoCommit(autoCommit); //Set autoCommit to its initial value
}