用java写一个程序，对一个运动会成绩原始文件“results.txt”,对运动员的竞赛成绩进行排名，将结果按格式保存到输出文件“out.txt”，成绩保留3位小数。results.txt文件内容为项目：男子100米预决赛 道次 号码 姓名 单位 成绩 备注 1 J2018 张三 计网 14.854 2 J1801 李四 信通 14.127 3 J5901 王五 机关二 13.320 4 J5114 赵六 继续教育 12.290 5 J1700 孙七 戏影 14.374 6 J5505 周八 后勤 15.

好的，以下是Java代码实现：

import java.io.*;
import java.util.*;

public class SportsRanking {
    public static void main(String[] args) throws IOException {
        File inFile = new File("results.txt");
        File outFile = new File("out.txt");
        BufferedReader reader = new BufferedReader(new FileReader(inFile));
        BufferedWriter writer = new BufferedWriter(new FileWriter(outFile));
        String line = null;
        List<Athlete> athletes = new ArrayList<>();

        while ((line = reader.readLine()) != null) {
            String[] fields = line.split(" ");
            String event = fields[0];
            int lane = Integer.parseInt(fields[1]);
            String number = fields[2];
            String name = fields[3];
            String unit = fields[4];
            double score = Double.parseDouble(fields[5]);

            Athlete athlete = new Athlete(event, lane, number, name, unit, score);
            athletes.add(athlete);
        }

        Collections.sort(athletes);

        int rank = 1;
        for (Athlete athlete : athletes) {
            writer.write(String.format("%-8s%-6d%-8s%-8s%-8s%.3f\n",
                    athlete.getEvent(), athlete.getLane(), athlete.getNumber(),
                    athlete.getName(), athlete.getUnit(), athlete.getScore()));
            rank++;
        }

        reader.close();
        writer.close();
    }
}

class Athlete implements Comparable<Athlete> {
    private String event;
    private int lane;
    private String number;
    private String name;
    private String unit;
    private double score;

    public Athlete(String event, int lane, String number, String name, String unit, double score) {
        this.event = event;
        this.lane = lane;
        this.number = number;
        this.name = name;
        this.unit = unit;
        this.score = score;
    }

    public String getEvent() {
        return event;
    }

    public int getLane() {
        return lane;
    }

    public String getNumber() {
        return number;
    }

    public String getName() {
        return name;
    }

    public String getUnit() {
        return unit;
    }

    public double getScore() {
        return score;
    }

    @Override
    public int compareTo(Athlete o) {
        return Double.compare(this.score, o.score);
    }
}

运行结果会将运动员按照成绩从小到大排名，并将结果按格式保存到输出文件“out.txt”中。