Guava Multiset介面

Multiset介面擴展設置有重複的元素，並提供了各種實用的方法來處理這樣的元素在集合中出現。

介面聲明

以下是com.google.common.collect.Multiset<E>介面的聲明：

@GwtCompatible
public interface Multiset<E>
   extends Collection<E>

介面方法

方法繼承

此介面繼承從以下介面方法：

• java.util.Collection

Multiset 示例

使用所選擇的編輯器創建下麵的java程式，比如說 C:/> Guava

import java.util.Iterator;
import java.util.Set;

import com.google.common.collect.HashMultiset;
import com.google.common.collect.Multiset;

public class GuavaTester {

   public static void main(String args[]){
      //create a multiset collection
      Multiset<String> multiset = HashMultiset.create();
      multiset.add("a");
      multiset.add("b");
      multiset.add("c");
      multiset.add("d");
      multiset.add("a");
      multiset.add("b");
      multiset.add("c");
      multiset.add("b");
      multiset.add("b");
      multiset.add("b");
      //print the occurrence of an element
      System.out.println("Occurrence of 'b' : "+multiset.count("b"));
      //print the total size of the multiset
      System.out.println("Total Size : "+multiset.size());
      //get the distinct elements of the multiset as set
      Set<String> set = multiset.elementSet();
      //display the elements of the set
      System.out.println("Set [");
      for (String s : set) {
         System.out.println(s);
      }
      System.out.println("]");
      //display all the elements of the multiset using iterator
      Iterator<String> iterator  = multiset.iterator();
      System.out.println("MultiSet [");
      while(iterator.hasNext()){
         System.out.println(iterator.next());
      }
      System.out.println("]");
      //display the distinct elements of the multiset with their occurrence count
      System.out.println("MultiSet [");
      for (Multiset.Entry<String> entry : multiset.entrySet())
      {
         System.out.println("Element: "+entry.getElement() +", Occurrence(s): " + entry.getCount());
      }
      System.out.println("]");

      //remove extra occurrences
      multiset.remove("b",2);
      //print the occurrence of an element
      System.out.println("Occurence of 'b' : "+multiset.count("b"));
   }
}

驗證結果

使用javac編譯器編譯如下類

C:\Guava>javac GuavaTester.java

現在運行GuavaTester看到的結果

C:\Guava>java GuavaTester

看到結果。

Occurence of 'b' : 5
Total Size : 10
Set [
d
b
c
a
]
MultiSet [
d
b
b
b
b
b
c
c
a
a
]
MultiSet [
Element: d, Occurence(s): 1
Element: b, Occurence(s): 5
Element: c, Occurence(s): 2
Element: a, Occurence(s): 2
]
Occurence of 'b' : 3