ConcurrentHashSet
时间: 2023-11-21 18:57:27 浏览: 29
ConcurrentHashSet是一个基于ConcurrentDictionary的并发哈希集实现,它支持每个项目的基本操作,而无需HashSet的set操作,因为它们在并发方案中意义不大。下面是创建和使用ConcurrentHashSet的代码示例:
```csharp
ConcurrentDictionary<string, int> certificationCosts = new ConcurrentDictionary<string, int>();
ConcurrentHashSet<string> concurrentHashSet = certificationCosts.Keys.ToConcurrentHashSet();
concurrentHashSet.TryAdd("OCEJWCD"); // 添加元素
concurrentHashSet.Contains("OCEJWCD"); // 判断元素是否存在
concurrentHashSet.TryRemove("OCEJWCD"); // 移除元素
```
相关问题
new ConcurrentHashSet
`ConcurrentHashSet`是基于`.NET`的`ConcurrentDictionary`实现的并发哈希集。它支持每个项目的基本操作,而无需`HashSet`的`set`操作,因为在并发方案中这些操作没有意义。以下是创建和使用`ConcurrentHashSet`的代码示例:
```csharp
using System.Collections.Concurrent;
// 创建ConcurrentHashSet
ConcurrentHashSet<int> concurrentHashSet = new ConcurrentHashSet<int>();
// 添加元素
concurrentHashSet.Add(1);
concurrentHashSet.Add(2);
concurrentHashSet.Add(3);
// 判断元素是否存在
bool contains = concurrentHashSet.Contains(2); // 返回true
// 删除元素
bool removed = concurrentHashSet.Remove(2); // 返回true
// 清空集合
concurrentHashSet.Clear();
```
java ConcurrentHashSet
Java并没有提供ConcurrentHashSet类,但是可以通过ConcurrentHashMap来实现类似的功能。ConcurrentHashMap是线程安全的哈希表,可以在多线程环境下使用。可以通过将值设置为一个固定的Object对象来实现ConcurrentHashSet的功能。具体实现如下:
```java
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
public class ConcurrentHashSet<E> extends Collections {
private final Set<E> set;
private final Object lock = new Object();
public ConcurrentHashSet() {
set = Collections.newSetFromMap(new ConcurrentHashMap<E, Boolean>());
}
public boolean add(E e) {
synchronized (lock) {
return set.add(e);
}
}
public boolean remove(Object o) {
synchronized (lock) {
return set.remove(o);
}
}
public boolean contains(Object o) {
return set.contains(o);
}
public boolean isEmpty() {
return set.isEmpty();
}
public int size() {
return set.size();
}
}
```
使用示例:
```java
ConcurrentHashSet<String> set = new ConcurrentHashSet<>();
set.add("hello");
set.add("world");
System.out.println(set.contains("hello")); // 输出:true
System.out.println(set.contains("java")); // 输出:false
```
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