java多线程找素数实例

 1 package ltb20180106;
 2 
 3 public class FindPrime implements Runnable{
 4 
 5     private int prime;
 6     private int q;
 7     private int w;
 8     
 9     public FindPrime(int nn,int mm) {
10         
11          q=nn;
12          w=mm;
13     }
14 
15     public void run() {
16         
17          getFindPrime(q,w);
18          
19     }
20     
21     public synchronized void getFindPrime(int min,int max) {
22         
23            int  k=max;
24            int  j=min;
25              
26             if(max<min) {
27                 
28                 System.out.println("最大值不能小于最小值,请重新输入!");
29                 
30             }else if(max<=0||min<0) {
31                 
32                 System.out.println("输入值不能是负数,或者最大值不能是零.");
33             }
34         
35         for(int i=k;i>j;i--) {
36             
37             if(i==1) { //1不是素数
38                 
39                 continue;
40             }
41             
42             prime=i%2;//去掉偶数
43             
44             if(prime==0&&i>3) {
45                 
46                 continue;
47             }
48             
49             prime=i%3;//去掉整除3的数,但是要大于7
50             
51             if(prime==0&&i>7) {
52                 
53                 continue;
54                 
55             }
56             
57             prime=i%5;//去掉整除5的数,但是要大于7
58             
59             
60              if(prime==0&&i>7) {
61                 
62                 continue;
63                 
64             }
65             
66             prime=i%7;//去掉整除7的数,,但是要大于7
67             
68 
69             if(prime==0&&i>7) {
70                 
71                 continue;
72                 
73             }
74             
75              
76             System.out.println("["+Thread.currentThread().getName()+"]"+"素数:"+i+"["+prime+"]");
77             
78             
79         }
80         
81     }
82     
83     public static void main(String[] args) {
84         
85         Thread t1=new Thread(new FindPrime(0,1000)); 
86        t1.start();
87        Thread t2=new Thread(new FindPrime(1001,2000));
88        t2.start();
89         Thread t3=new Thread(new FindPrime(2001,3000));
90        t3.start();
91         
92     }
93 
94 }