Java实现进程调度算法(一) FCFS(先来先服务)

fcfs类（主类）

只有calc()中涉及了算法，init()和printresult()都只有简单的输入输出操作。

 1 package xqy.algorithm;
 2 
 3 import java.util.arraylist;
 4 import java.util.scanner;
 5 
 6 import xqy.util.tools;
 7 import xqy.been.process;
 8 
 9 /**
10  * @author xqy
11  * @date 2018年12月19日19:15:01
12  * @description 对先到的任务先处理，后到的任务后处理。
13  */
14 
15 public class fcfs {
16     private int processnumber;
17     private arraylist<process> processlist;
18 
19     public fcfs() {
20         init();
21         calc();
22         tools.printresult(processlist);
23     }
24 
25     private void init() {
26         scanner sc = new scanner(system.in);
27 
28         system.out.print("<fcfs> please enter the process num:");
29         processnumber = sc.nextint();
30 
31         processlist = new arraylist<process>();
32         for (int i = 0; i < processnumber; i++) {
33             processlist.add(new process());
34         }
35 
36         system.out.println("<fcfs> please enter each process arrival time:");
37         for (int i = 0; i < processnumber; i++) {
38             system.out.print("    process" + (i + 1) + ":");
39             processlist.get(i).setarrivaltime(sc.nextint());
40         }
41 
42         system.out.println("<fcfs> please enter each process service time:");
43         for (int i = 0; i < processnumber; i++) {
44             system.out.print("    process" + (i + 1) + ":");
45             processlist.get(i).setservicestime(sc.nextint());
46         }
47     }
48 
49     private void calc() {
50         int timenow = 0;
51         process opprocess;
52         
53         for (int i = 0; i < processnumber; i++) {
54             opprocess = processlist.get(i);
55             
56             int waittime = timenow - opprocess.getarrivaltime();
57             int completiontime = timenow + opprocess.getservicestime();
58             int turnaroundtime = completiontime
59                     - opprocess.getarrivaltime();
60             double turnaroundtimewithweight = (double) turnaroundtime
61                     / opprocess.getservicestime();
62 
63             opprocess.setstarttime(timenow);
64             opprocess.setwaittime(waittime);
65             opprocess.setcompletiontime(completiontime);
66             opprocess.setturnaroundtime(turnaroundtime);
67             opprocess.setturnaroundtimewithweight(
68                     turnaroundtimewithweight);
69 
70             timenow += opprocess.getservicestime();
71         }
72     }
73     
74     public static void main(string [] args) {
75         new fcfs();
76     }
77 }

process类

模拟了进程，对属性进行了封装。

 1 package xqy.been;
 2 
 3 public class process {
 4     private int arrivaltime;
 5     private int servicestime;
 6     private int remainservicetime;
 7     private int starttime;
 8     private int waittime;
 9     private int completiontime;
10     
11     /**
12      * turnaroundtime = completiontime - arrivaltime
13      */
14     private int turnaroundtime;
15     
16     /**
17      * turnaroundtimewithweight = turnaroundtime / servicestime
18      */
19     private double turnaroundtimewithweight;
20     
21     public process() {
22         ;
23     }
24 
25     public int getarrivaltime() {
26         return arrivaltime;
27     }
28 
29     public void setarrivaltime(int arrivaltime) {
30         this.arrivaltime = arrivaltime;
31     }
32 
33     public int getservicestime() {
34         return servicestime;
35     }
36 
37     public void setservicestime(int servicestime) {
38         this.servicestime = servicestime;
39     }
40 
41     public int getremainservicetime() {
42         return remainservicetime;
43     }
44 
45     public void setremainservicetime(int remainservicetime) {
46         this.remainservicetime = remainservicetime;
47     }
48 
49     public int getstarttime() {
50         return starttime;
51     }
52 
53     public void setstarttime(int starttime) {
54         this.starttime = starttime;
55     }
56 
57     public int getwaittime() {
58         return waittime;
59     }
60 
61     public void setwaittime(int waittime) {
62         this.waittime = waittime;
63     }
64 
65     public int getcompletiontime() {
66         return completiontime;
67     }
68 
69     public void setcompletiontime(int completiontime) {
70         this.completiontime = completiontime;
71     }
72 
73     public int getturnaroundtime() {
74         return turnaroundtime;
75     }
76 
77     public void setturnaroundtime(int turnaroundtime) {
78         this.turnaroundtime = turnaroundtime;
79     }
80 
81     public double getturnaroundtimewithweight() {
82         return turnaroundtimewithweight;
83     }
84 
85     public void setturnaroundtimewithweight(double turnaroundtimewithweight) {
86         this.turnaroundtimewithweight = turnaroundtimewithweight;
87     }
88 
89     @override
90     public string tostring() {
91         return "process [arrivaltime=" + arrivaltime + ", servicestime="
92                 + servicestime + ", remainservicetime=" + remainservicetime
93                 + ", starttime=" + starttime + ", waittime=" + waittime
94                 + ", completiontime=" + completiontime + ", turnaroundtime="
95                 + turnaroundtime + ", turnaroundtimewithweight="
96                 + turnaroundtimewithweight + "]";
97     }
98 }

tools类

因为我这次作业要实现几个类似的算法，所以我把每个算法中都要用到的方法都提取出来作为单独的工具类。

也可以将这些工具方法都放入fcfs类中。

 1 package xqy.util;
 2 
 3 import java.util.arraylist;
 4 
 5 import xqy.been.process;
 6 
 7 public class tools {
 8 
 9     public static double calcaverageturnaroundtime(
10             arraylist<process> processlist) {
11         double sum = 0;
12         for (int i = 0; i < processlist.size(); i++) {
13             sum += processlist.get(i).getturnaroundtime();
14         }
15         return math.round(sum / processlist.size() * 100) / 100.0;
16     }
17 
18     public static double calcaverageturnaroundtimewithweight(
19             arraylist<process> processlist) {
20         double sum = 0;
21         for (int i = 0; i < processlist.size(); i++) {
22             sum += processlist.get(i).getturnaroundtimewithweight();
23         }
24         return math.round(sum / processlist.size() * 100) / 100.0;
25     }
26 
27     public static void printresult(arraylist<process> processlist) {
28         system.out.println("\n    #result#");
29 
30         system.out.print("\tarrive:\t\t");
31         for (int i = 0; i < processlist.size(); i++) {
32             system.out.print(processlist.get(i).getarrivaltime() + "\t");
33         }
34         system.out.println();
35 
36         system.out.print("\tservice:\t");
37         for (int i = 0; i < processlist.size(); i++) {
38             system.out.print(processlist.get(i).getservicestime() + "\t");
39         }
40         system.out.println();
41 
42         system.out.print("\tstart:\t\t");
43         for (int i = 0; i < processlist.size(); i++) {
44             system.out.print(processlist.get(i).getstarttime() + "\t");
45         }
46         system.out.println();
47 
48         system.out.print("\twait:\t\t");
49         for (int i = 0; i < processlist.size(); i++) {
50             system.out.print(processlist.get(i).getwaittime() + "\t");
51         }
52         system.out.println();
53 
54         system.out.print("\tfinish:\t\t");
55         for (int i = 0; i < processlist.size(); i++) {
56             system.out.print(processlist.get(i).getcompletiontime() + "\t");
57         }
58         system.out.println();
59 
60         system.out.print("\tturn around:\t");
61         for (int i = 0; i < processlist.size(); i++) {
62             system.out.print(processlist.get(i).getturnaroundtime() + "\t");
63         }
64         system.out.println();
65 
66         system.out.print("\tta wight:\t");
67         for (int i = 0; i < processlist.size(); i++) {
68             system.out.print(math.round(processlist.get(i)
69                     .getturnaroundtimewithweight() * 100) / 100.0 + "\t");
70         }
71         system.out.println();
72 
73         system.out.println("\taverage turn around time:"
74                 + tools.calcaverageturnaroundtime(processlist) + "\t");
75         system.out.println("\taverage turn around time with wight:"
76                 + tools.calcaverageturnaroundtimewithweight(processlist));
77         
78         system.out.println();
79     }
80 }