将地图键与字符串列表进行比较 [英] Compare map key with a list of strings

问题描述

可以与java中的字符串arraylist进行比较

can map be compare with arraylist of string in java

private Map<String, String> checkInScopeLobs(Map<String, String> allLobsChkBx)
    {
        Map<String, String> inScopeLobs = new HashMap<String, String>();; 
        for (Map.Entry<String, String> entry : allLobsChkBx.entrySet())
        {
          if(entry.getKey().contains("1") || entry.getKey().contains("2") || entry.getKey().contains("3")){
              inScopeLobs.put(entry.getKey(), entry.getValue());
          }
        }
        return inScopeLobs;
    }

这是一个正确的方法吗？

is this a correct way ?

推荐答案

您可以使用 keySet（）。此方法返回 Set 的键（更多信息，关于地图的Oracle文档）。这意味着在整个地图上迭代的开销更少。在下面的情况下，您只会请求匹配键的值。

You can make use of keySet(). This method returns a Set of keys (for more info, Docs from Oracle about Map). This means less overhead than iterating over your whole map. In the following case you'll only request values of matching keys.

还有一些其他错误，如双分号，不必在初始化时定义地图。

There are some other faults like a double semicolon and since JDK7 you don't have to define your map when initializing.

private Map<String, String> checkInScopeLobs(Map<String, String> allLobsChkBx) {
    Map<String, String> inScopeLobs = new HashMap();
    List<String> keys = Arrays.asList( { "1", "2", "3" } );
    for(String key : allLobsChkBx.keySet()) {
        if(keys.contains(key)) {
            inScopeLobs.put(key, allLobsChkBx.get(key));
        }
    }
    return inScopeLobs;
}

为什么不使用 Integer 而不是 String ，因为您只储存数字。

Why aren't you using an Integer instead of a String, since you're only storing numbers.

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