Java 集合 使用索引搜索元素

import java.util.Vector;
public class SearchVector {
  public static void main(String[] args) { 
     // Create a Vector object
     Vector<String> vector = new Vector<String>();

     //Add elements to Vector
     vector.add("Kate");
     vector.add("Patt");
     vector.add("Kluge");
     vector.add("Karon");
     vector.add("Patt");
     vector.add("Monica");
     vector.add("Patt");

     //This would return the index of first occurrence
     int first_index = vector.indexOf("Patt");
     System.out.println("First Occurrence of Patt at index: "+first_index);

     //This would return the index of last occurrence
     int last_index = vector.lastIndexOf("Patt");
     System.out.println("Last Occurrence of Patt at index: "+last_index);

     //This would start search from index 2(inclusive)
     int after_index = vector.indexOf("Patt", 2);
     System.out.println("Occurrence after index 2: "+after_index);

     //This would search the element backward starting from index 6(inclusive)
     int before_index = vector.lastIndexOf("Patt", 6);
     System.out.println("Occurrence before index 6: "+before_index);
  } 
}

First Occurrence of Patt at index: 1
Last Occurrence of Patt at index: 6
Occurrence after index 2: 4
Occurrence before index 6: 6