java - 新 ConcurrentHashMap 新 ConcurrentHashMap

Question

我正在尝试使用 ConcurrentHashMap 初始化 ConcurrentHashMap

private final ConcurrentHashMap<
    String, 
    ConcurrentHashMap<String, Double>
> myMulitiConcurrentHashMap = new ConcurrentHashMap<
    String, 
    new ConcurrentHashMap<String, Double>()
>();

但是javac给出了

HashMapper.java:132: error: illegal start of type
    new ConcurrentHashMap<String, Double>()
    ^
HashMapper.java:132: error: '(' or '[' expected
    new ConcurrentHashMap<String, Double>()
        ^
HashMapper.java:132: error: ';' expected
    new ConcurrentHashMap<String, Double>()

指向第二个new。

如何正确地new初始化myMulitiConcurrentHashMap？

Answer 1

您没有初始化内部 ConcurrentHashMap<String, Double> ;只需执行以下操作即可:

new ConcurrentHashMap<
    String, 
    ConcurrentHashMap<String, Double>
>();