非抢占式，短作业优先调度算法 | Java语言实现

package com.company.osExperiment.algorithm;

import com.company.osExperiment.entity.PCB;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

import static com.company.osExperiment.entity.PCB.R;
import static com.company.osExperiment.util.ResultUtil.addResult;

/**
 * 非抢占式，短作业优先调度算法
 * @Author swsbty
 * @Date 2020/6/9 4:31
 */

public class SJF {

    private int current = 0;     // 记录系统当前时间的变量
    private List<PCB> processList;

    /*
    启动方法
     */
    public void start() {
        processList = new ArrayList<>();
        System.out.println("time 1=1000 time slice");
        addResult("time 1=1000 time slice");
        inputProcess();
        sort();
        run();
    }

    /*
    执行调度算法
     */
    private void run() {
        while (true) {
            if (processList.size() == 0) {  // 如果所有进程都执行完毕，就终止循环
                return;
            }
            runProcess();
        }
    }

    /*
    运行进程
     */
    private void runProcess() {
        for (PCB pcb : processList) {
            if (pcb.state == R && pcb.arriveTime <= current) {  // 如果进程没有执行完毕，同时到达时间小于等于当前时间
                System.out.println("当前时间：" + (current * 1000) + "，进程" + pcb.name + " 开始运行");
                addResult("当前时间：" + (current * 1000) + "，进程" + pcb.name + " 开始运行");
                current += pcb.runtime; // 当前时间加上运行时间
                System.out.println("当前时间：" + (current * 1000) + "，进程" + pcb.name + " 运行结束");
                addResult("当前时间：" + (current * 1000) + "，进程" + pcb.name + " 运行结束");
                processList.remove(pcb);    // 删除该进程
                break;
            }
        }
    }

    /*
    录入进程
     */
    private void inputProcess() {
        int num;        // 要建立的进程数
        System.out.print("你想运行多少个进程:");
        addResult("你想运行多少个进程:");

        Scanner input = new Scanner(System.in);
        num = input.nextInt();
        addResult("" + num);
        for (int i = 0;i < num;i++) {
            PCB p = new PCB();
            System.out.print(String.format("请输入第 %3d 个进程的名字:", i + 1));
            addResult(String.format("请输入第 %3d 个进程的名字:", i + 1));
            p.name = input.next();
            addResult(p.name);

            System.out.print("                     运行时间:");
            addResult("                     运行时间:");
            p.runtime = input.nextInt();
            addResult("" + p.runtime);

            System.out.print("                        到达时间:");
            addResult("                        到达时间:");
            p.arriveTime = input.nextInt();
            addResult("" + p.arriveTime);


            p.state = R;
            processList.add(p);
        }
    }

    /*
    ☆选择排序
    该算法把录入的进程，按照运行时间，由小到大排序
     */
    private void sort() {
        for (int i = 0;i < processList.size() - 1;i++) {
            for (int j = i + 1;j < processList.size();j++) {
                if (processList.get(i).runtime > processList.get(j).runtime) {
                    PCB pi = processList.get(i);
                    PCB pj = processList.get(j);
                    processList.set(i, pj);
                    processList.set(j, pi);
                }
            }
        }
    }
}