java多线程读写文件实例，java多线程实例

java多线程读写文件实例，java多线程实例

Java多线程读文件：

[java] view plain copy

1. package com.myjava;  
2. import java.io.BufferedReader;  
3. import java.io.FileNotFoundException;  
4. import java.io.FileReader;  
5. import java.io.IOException;  
6. import java.util.ArrayList;  
7. import java.util.List;  
8. public class ThreadReadDemo {  
9.   
10.     /**Java多线程读大文件 
11.      * @param args 
12.      */  
13.     public static void main(String[] args) {  
14.         Thread t1=new Thread(new MultiThread(),"A");  
15.         Thread t2=new Thread(new MultiThread(),"B");  
16.         t1.start();  
17.         t2.start();  
18.     }  
19.   
20. }  
21.   
22.   
23.  class MultiThread implements Runnable{   
24.     private static BufferedReader br = null;  
25.     private List<String> list;  
26.       
27.     static{  
28.         try {  
29.             br = new BufferedReader(new FileReader("F://ThreadDemo.txt"),10);  
30.         } catch (FileNotFoundException e) {  
31.             // TODO Auto-generated catch block  
32.             e.printStackTrace();  
33.         }  
34.     }  
35.       
36.     public void run() {  
37.         String line = null;  
38.         int count = 0;  
39.         while(true) {  
40.             //System.out.println(Thread.currentThread().getName());  
41.             this.list = new ArrayList<String>();  
42.             synchronized(br) {  
43.                 try {  
44.                     while((line = br.readLine()) != null) {  
45.                         if(count<15) {  
46.                             list.add(line);  
47.                             count++;  
48.                         }else {  
49.                             list.add(line);  
50.                             count = 0;  
51.                             break;  
52.                         }  
53.                     }  
54.                 } catch (IOException e) {  
55.                     e.printStackTrace();  
56.                 }  
57.             }  
58.             try {  
59.                 Thread.sleep(1);  
60.                 display(this.list);  
61.             } catch (InterruptedException e) {  
62.                 e.printStackTrace();  
63.             }  
64.             if(line == null)  
65.                 break;  
66.         }  
67.           
68.           
69.     }  
70.       
71.     public void display(List<String> list) {  
72.         for(String str:list) {  
73.             System.out.println(str);  
74.         }  
75.         System.out.println(list.size());  
76.     }  
77.       
78. }  

java多线程写文件：

[java] view plain copy

1. package com.myjava;  
2.   
3. import java.io.File;  
4. import java.io.FileNotFoundException;  
5. import java.io.FileOutputStream;  
6. import java.io.IOException;  
7. import java.util.concurrent.ConcurrentLinkedQueue;  
8.   
9. /** 
10.  * 多线程下写文件 
11.  *  
12.  * @author Administrator 
13.  *  
14.  */  
15. public class ThreadDemo {  
16.   
17.     public static void main(String[] args) {  
18.         File file=new File("F:"+File.separator+"ThreadDemo.txt");  
19.         try {  
20.             FileOutputStream out=new FileOutputStream(file, true);  
21.             ConcurrentLinkedQueue<String> queue=new ConcurrentLinkedQueue<String>();  
22.             for(int i=0;i<10;i++){  
23.                 new Thread(new MyThread(queue,"线程"+i+",")).start();//多线程往队列中写入数据  
24.             }  
25.             new Thread(new DealFile(out,queue)).start();//监听线程，不断从queue中读数据写入到文件中  
26.             try {  
27.                 Thread.sleep(3000);  
28.                 if(!Thread.currentThread().isAlive()){  
29.                     System.out.println("线程已结束");  
30.                 }  
31.             } catch (InterruptedException e) {  
32.                 // TODO Auto-generated catch block  
33.                 e.printStackTrace();  
34.             }  
35.               
36.         } catch (FileNotFoundException e) {  
37.             e.printStackTrace();  
38.         }  
39.           
40.     }  
41. }  
42.   
43. /** 
44.  * 将要写入文件的数据存入队列中 
45.  *  
46.  * @author Administrator 
47.  *  
48.  */  
49. class MyThread implements Runnable {  
50.     private ConcurrentLinkedQueue<String> queue;  
51.     private String contents;  
52.   
53.     public MyThread() {  
54.     }  
55.   
56.     public MyThread(ConcurrentLinkedQueue<String> queue, String contents) {  
57.         this.queue = queue;  
58.         this.contents = contents;  
59.     }  
60.   
61.     @Override  
62.     public void run() {  
63.         try {  
64.             Thread.sleep(100);  
65.         } catch (InterruptedException e) {  
66.             // TODO Auto-generated catch block  
67.             e.printStackTrace();  
68.         }  
69.         queue.add(contents);  
70.     }  
71. }  
72. /** 
73.  * 将队列中的数据写入到文件 
74.  * @author Administrator 
75.  * 
76.  */  
77. class DealFile implements Runnable {  
78.     private FileOutputStream out;  
79.     private ConcurrentLinkedQueue<String> queue;  
80.   
81.     public DealFile() {  
82.     }  
83.   
84.     public DealFile(FileOutputStream out, ConcurrentLinkedQueue<String> queue) {  
85.         this.out = out;  
86.         this.queue = queue;  
87.     }  
88.   
89.     @Override  
90.     public void run() {  
91.         synchronized (queue) {  
92.             while (true) {  
93.                 if (!queue.isEmpty()) {  
94.                     try {  
95.                         out.write(queue.poll().getBytes("UTF-8"));  
96.                     } catch (IOException e) {  
97.                         // TODO Auto-generated catch block  
98.                         e.printStackTrace();  
99.                     }  
100.                 }  
101.                 try {  
102.                     Thread.sleep(100);  
103.                 } catch (InterruptedException e) {  
104.                     e.printStackTrace();  
105.                 }  
106.             }  
107.         }  
108.   
109.     }  
110.   
111. }