相关疑难解决方法(0)

不知怎的,我的旧问题已经关闭,所以我开了一个新问题:

我正在使用Java Generics从SQL查询中实现通用双向哈希映射.它应该能够来回映射String,Integer对的任意组合.它应该像这样使用:

String sql = "SELECT string_val, int_val FROM map_table";
PickMap<String, Integer> pm1 = new PickMap<String, Integer>(sql);

String key1 = "seven";
Integer value1 = pm1.getLeft2Right(key1);

Integer key2 = 7;
String value2 = pm1.getRightToLeft(key2);

当然应该可以创建一个pm(整数,整数)等等......

我对Pick Map的实现看起来像这样(没有getter ...):

public class PickMap<L, R> {

    private final HashMap<L, R> left2Right = new HashMap<L, R>();
    private final HashMap<R, L> right2Left = new HashMap<R, L>();

    public PickMap(String sql) throws OException {
        DTable d = new DTable(sql);
        int colTypeL = d.t.getColType(1);
        int colTypeR = d.t.getColType(2); …