不区分大小写的字符串作为 HashMap 键 [英] Case insensitive string as HashMap key
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问题描述
出于以下原因,我想使用不区分大小写的字符串作为 HashMap 键.
I would like to use case insensitive string as a HashMap key for the following reasons.
- 在初始化期间,我的程序使用用户定义的字符串创建 HashMap
- 在处理事件(在我的情况下是网络流量)时,我可能会在不同的情况下收到 String,但我应该能够从 HashMap 中找到
而忽略这种情况从流量中收到.
- During initialization, my program creates HashMap with user defined String
- While processing an event (network traffic in my case), I might received String in a different case but I should be able to locate the
<key, value>
from HashMap ignoring the case I received from traffic.
我遵循了这种方法
CaseInsensitiveString.java
CaseInsensitiveString.java
public final class CaseInsensitiveString {
private String s;
public CaseInsensitiveString(String s) {
if (s == null)
throw new NullPointerException();
this.s = s;
}
public boolean equals(Object o) {
return o instanceof CaseInsensitiveString &&
((CaseInsensitiveString)o).s.equalsIgnoreCase(s);
}
private volatile int hashCode = 0;
public int hashCode() {
if (hashCode == 0)
hashCode = s.toUpperCase().hashCode();
return hashCode;
}
public String toString() {
return s;
}
}
LookupCode.java
LookupCode.java
node = nodeMap.get(new CaseInsensitiveString(stringFromEvent.toString()));
因此,我为每个事件创建了一个新的 CaseInsensitiveString 对象.因此,它可能会影响性能.
Because of this, I'm creating a new object of CaseInsensitiveString for every event. So, it might hit performance.
有没有其他方法可以解决这个问题?
Is there any other way to solve this issue?
推荐答案
Map<String, String> nodeMap =
new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
这正是您所需要的.
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