搭建流水线：程序有时候需要将任务按流水线进行，例如评判比赛选手 的任务按流水线分为依次进行的三个步骤：录入裁判给选手的分数，去掉一个最 高分和一个最低分，计算出平均成绩。编写程序，搭建评判选手流水线。在流水线上再增加一个对象，该对象负责判 断选手的成绩是否达到及格标准。用java语言来实现

以下是一个简单的Java程序，用于搭建评判选手流水线：

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

public class Pipeline {

    public static void main(String[] args) {
        // 创建选手列表
        List<Player> players = new ArrayList<>();
        players.add(new Player("小明", 80));
        players.add(new Player("小红", 90));
        players.add(new Player("小刚", 85));

        // 创建流水线对象
        Pipeline pipeline = new Pipeline();
        // 录入分数
        pipeline.recordScore(players);
        // 去掉最高分和最低分
        pipeline.removeExtremeScores(players);
        // 计算平均成绩
        double averageScore = pipeline.calculateAverageScore(players);
        // 判断是否及格
        pipeline.checkPass(players, averageScore);
    }

    // 录入裁判给选手的分数
    public void recordScore(List<Player> players) {
        for (Player player : players) {
            player.setScore((int) (Math.random() * 100));
            System.out.println(player.getName() + "的分数为：" + player.getScore());
        }
    }

    // 去掉一个最高分和一个最低分
    public void removeExtremeScores(List<Player> players) {
        Collections.sort(players, (p1, p2) -> Integer.compare(p1.getScore(), p2.getScore()));
        players.remove(0); // 去掉最低分
        players.remove(players.size() - 1); // 去掉最高分
        for (Player player : players) {
            System.out.println(player.getName() + "的中间三个分数为：" + player.getScores());
        }
    }

    // 计算平均成绩
    public double calculateAverageScore(List<Player> players) {
        double totalScore = 0;
        for (Player player : players) {
            totalScore += player.getScore();
        }
        double averageScore = totalScore / players.size();
        System.out.println("选手的平均成绩为：" + averageScore);
        return averageScore;
    }

    // 判断是否及格
    public void checkPass(List<Player> players, double passScore) {
        for (Player player : players) {
            if (player.getScore() >= passScore) {
                System.out.println(player.getName() + "及格！");
            } else {
                System.out.println(player.getName() + "不及格！");
            }
        }
    }

}

class Player {

    private String name;
    private int score;
    private List<Integer> scores = new ArrayList<>();

    public Player(String name, int score) {
        this.name = name;
        this.score = score;
    }

    public String getName() {
        return name;
    }

    public int getScore() {
        return score;
    }

    public void setScore(int score) {
        this.score = score;
        scores.add(score);
    }

    public List<Integer> getScores() {
        return scores;
    }

}

这个程序使用了Java的Lambda表达式来定义排序规则，可以实现去掉最高分和最低分的操作。同时，为了记录选手的所有分数，我们在Player类中增加了一个scores列表。