Java中Collections.frequency检查值频率

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

public class test {
    public static void main(String[] args) {
        List<Integer> values = Arrays.asList( 5, 0, 0, 2 );
        List<String> list = new ArrayList<String>();
        int occurrences = Collections.frequency(values, 0);
        System.out.println("occurrences of 0 is " + occurrences);
        
        occurrences = Collections.frequency(values, 5);
        System.out.println("occurrences of 5 is " + occurrences);
    }
}

运行结果如下：