Java Stream limit()方法

limit(long N)是 java.util.stream. Stream对象的一个方法。limit()在有序的并行管道上可能是相当昂贵的，如果N的值很大，因为limit(N)被限制为返回遇到的顺序中的前N个元素，而不是任何N个元素。

语法:

Stream<T> limit(long N)

其中N是流应限制的元素数，该函数返回新的流作为输出。

异常： 如果N的值是负的，那么函数会抛出 IllegalArgumentException 。

下面是一些例子，以便更好地理解该函数的实现。

例1 :

// Java code to show implementation
// of limit() function
import java.util.*;
  
class GFG {
  
    // Driver code
    public static void main(String[] args)
    {
  
        // Creating a list of integers
        List<Integer> list = new ArrayList<Integer>();
  
        // adding elements in the list
        list.add(-2);
        list.add(0);
        list.add(2);
        list.add(4);
        list.add(6);
        list.add(8);
        list.add(10);
        list.add(12);
        list.add(14);
        list.add(16);
  
        // setting the value of N as 4
        int limit = 4;
        int count = 0;
        Iterator<Integer> it = list.iterator();
  
        // Iterating through the list of integers
        while (it.hasNext()) {
            it.next();
            count++;
  
            // Check if first four i.e, (equal to N)
            // integers are iterated.
            if (count > limit) {
  
                // If yes then remove all the remaining integers.
                it.remove();
            }
        }
  
        System.out.print("New stream of length N"
                         + " after truncation is : ");
  
        // Displaying new stream of length
        // N after truncation
        for (Integer number : list) {
            System.out.print(number + " ");
        }
    }
}

输出:

New stream of length N after truncation is : -2 0 2 4 

应用 :

// Java code to show the use of limit() function
import java.util.stream.Stream;
import java.util.ArrayList;
import java.util.List;
 class gfg{
       
     // Function to limit the stream upto given range, i.e, 3
     public static Stream<String> limiting_func(Stream<String> ss, int range){
         return ss.limit(range);
     }
       
     // Driver code
     public static void main(String[] args){
           
         // list to save stream of strings
         List<String> arr = new ArrayList<>();
           
         arr.add("geeks");
         arr.add("for");
         arr.add("geeks");
         arr.add("computer");
         arr.add("science");
          
         Stream<String> str = arr.stream();
           
         // calling function to limit the stream to range 3
         Stream<String> lm = limiting_func(str,3);
         lm.forEach(System.out::println);
     }
 }

输出:

geeks
for
geeks