Question

我有一个包含一些HashMap类型的类：

private class XmlHandler extends DefaultHandler{
    private HashMap<String, String> Attribs;
    private HashMap<String, List<Attribs> >FragmentNode;
    private HashMap<String, List<FragmentNode> > ActivityNode;

编译时，我收到此错误：

cannot find symbol FragmentNode and Attribs.

如果我修改插入原始类型的声明，即将HashMap<String, List<Attribs>更改为HashMap<String, HashMap<String, String>>编译器停止投诉。

我需要这样做吗？ Java不了解像这样的类型声明吗？

Answer 1

FragmentNode和Attribs不是类型，它是变量，您不能将变量指定为HashMap的类型。

你可以这样做：

private HashMap<String, List<HashMap<String, String>>> FragmentNode;

或者您可以创建一个具有Attribs HashMap的类，如：

public class Attribs {

    private HashMap<String, String> Attribs;

}

然后：

 private HashMap<String, List<Attribs>> FragmentNode;

Answer 2

好像你正在将类型与属性混合。

如果您想要这样的特定层次结构，则应定义新类：

class Attribs extends HashMap<String, String> {}
class FragmentNode extends HashMap<String, List<Attribs>> {}
class ActivityNode extends HashMap<String, List<FragmentNode>> {}

然后你可以创建这样的成员：

private class XmlHandler extends DefaultHandler {
    private Attribs attribs;
    private FragmentNode fragmentNode;
    private ActivityNode activityNode;
}

HashMap类型找不到符号

2 个答案: