Question

如何提高此代码的性能？我必须创造我通过查询返回的查询返回的每个项目的对象价值数组。我不知道预先分配对象是否会有所帮助因为每次检索结果项目时我都在新建一个对象此外，我将对象存储在ids =＆gt;的地图中。对象和ID正在存在存储在id列表中以便以后更快地访问。

        java.util.Vector<Integer> resultList = new java.util.Vector<Integer>();
        while (result.next()) {
            Ptrobject ptrobject = new Ptrobject(connection());

            DataValue[] values = result.getValues();

            int idx = 0;
            ptrobject.id           = values[idx++].getInt();
            ptrobject.unty        = values[idx++].getString();
            ptrobject.tumCode     = values[idx++].getString();
            ptrobject.eldName     = values[idx++].getString();
            ptrobject.atTD        = values[idx++].getString();
            ptrobject.stOper      = values[idx++].getString();
            ptrobject.aseName     = values[idx++].getString();
            ptrobject.aseNbr      = values[idx++].getString();
            ptrobject.erator      = values[idx++].getString();
            ptrobject.odFM        = values[idx++].getString();
            ptrobject.marks       = values[idx++].getString();
            ptrobject.ate         = values[idx++].getString();
            ptrobject.mCode       = values[idx++].getString();
            ptrobject.jectLabel     = values[idx++].getString();
            ptrobject.jectName      = values[idx++].getString();
            ptrobject.jectNumber    = values[idx++].getString();
            ptrobject.ud             = (Timestamp) values[idx++].getPtrobject();

            s_cache.getMap().put(ptrobject.id, ptrobject);
            resultList.add(ptrobject.id);
        }

Answer 1

将对象定义放在while语句

之外

Ptrobject ptrobject;
DataValue[] values;
int idx;
while (result.next()) {
        ptrobject = new Ptrobject(connection());
        values = result.getValues();
        idx=0;
        .....

我知道最小范围说不要这样做，但如果你想要速度，那就是。这里是内部与外部声明的标记。

http://www.gunduru.com/post/107249109253/declaring-variables-inside-or-outside-of-a-loop

可以改善循环中新对象的性能

1 个答案: