Java多线程读文件：
package com.myjava;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class ThreadReadDemo {
/**Java多线程读大文件
* @param args
*/
public static void main(String[] args) {
Thread t1=new Thread(new MultiThread(),"A");
Thread t2=new Thread(new MultiThread(),"B");
t1.start();
t2.start();
}
}
class MultiThread implements Runnable{
private static BufferedReader br = null;
private List<String> list;
static{
try {
br = new BufferedReader(new FileReader("F://ThreadDemo.txt"),10);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void run() {
String line = null;
int count = 0;
while(true) {
//System.out.println(Thread.currentThread().getName());
this.list = new ArrayList<String>();
synchronized(br) {
try {
while((line = br.readLine()) != null) {
if(count<15) {
list.add(line);
count++;
}else {
list.add(line);
count = 0;
break;
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
try {
Thread.sleep(1);
display(this.list);
} catch (InterruptedException e) {
e.printStackTrace();
}
if(line == null)
break;
}
}
public void display(List<String> list) {
for(String str:list) {
System.out.println(str);
}
System.out.println(list.size());
}
}
java多线程写文件：
package com.myjava;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.concurrent.ConcurrentLinkedQueue;
/**
* 多线程下写文件
*
* @author Administrator
*
*/
public class ThreadDemo {
public static void main(String[] args) {
File file=new File("F:"+File.separator+"ThreadDemo.txt");
try {
FileOutputStream out=new FileOutputStream(file, true);
ConcurrentLinkedQueue<String> queue=new ConcurrentLinkedQueue<String>();
for(int i=0;i<10;i++){
new Thread(new MyThread(queue,"线程"+i+",")).start();//多线程往队列中写入数据
}
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
try {
Thread.sleep(3000);
if(!Thread.currentThread().isAlive()){
System.out.println("线程已结束");
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}
/**
* 将要写入文件的数据存入队列中
*
* @author Administrator
*
*/
class MyThread implements Runnable {
private ConcurrentLinkedQueue<String> queue;
private String contents;
public MyThread() {
}
public MyThread(ConcurrentLinkedQueue<String> queue, String contents) {
this.queue = queue;
this.contents = contents;
}
@Override
public void run() {
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
queue.add(contents);
}
}
/**
* 将队列中的数据写入到文件
* @author Administrator
*
*/
class DealFile implements Runnable {
private FileOutputStream out;
private ConcurrentLinkedQueue<String> queue;
public DealFile() {
}
public DealFile(FileOutputStream out, ConcurrentLinkedQueue<String> queue) {
this.out = out;
this.queue = queue;
}
@Override
public void run() {
synchronized (queue) {
while (true) {
if (!queue.isEmpty()) {
try {
out.write(queue.poll().getBytes("UTF-8"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}