java多線程復制文件的實例代碼
更新時間：2013年03月19日 11:06:50 作者：
java多線程復制文件的實例代碼，需要的朋友可以參考一下
復制代碼 代碼如下:
package com.test;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
public class FileCoper {
private static final String _ORIGIN_FILE_MODE = "r";
private static final String _TARGET_FILE_MODE = "rw";
private static long time1 = 0l;
private String originFileName;
private String targetFileName;
private RandomAccessFile originFile;
private RandomAccessFile targetFile;
private int threadCount;
private static int totalThreadCount = 0;
private static int executedCount = 0;
public FileCoper() {
this.threadCount = 1;
totalThreadCount = this.threadCount;
}
public FileCoper(String originFile, String targetFile) {
try {
this.originFileName = originFile;
this.targetFileName = targetFile;
this.originFile = new RandomAccessFile((originFile), FileCoper._ORIGIN_FILE_MODE);
this.targetFile = new RandomAccessFile((targetFile), FileCoper._TARGET_FILE_MODE);
this.threadCount = 1;
totalThreadCount = this.threadCount;
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
public FileCoper(String originFile, String targetFile, int threadCount) {
try {
this.originFileName = originFile;
this.targetFileName = targetFile;
this.originFile = new RandomAccessFile((originFile), FileCoper._ORIGIN_FILE_MODE);
this.targetFile = new RandomAccessFile((targetFile), FileCoper._TARGET_FILE_MODE);
this.threadCount = 1;
totalThreadCount = this.threadCount;
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
public void init(String originFile, String targetFile) throws Exception {
this.originFileName = originFile;
this.targetFileName = targetFile;
this.originFile = new RandomAccessFile((originFile), FileCoper._ORIGIN_FILE_MODE);
this.targetFile = new RandomAccessFile((targetFile), FileCoper._TARGET_FILE_MODE);
this.threadCount = 1;
totalThreadCount = this.threadCount;
}
public void init(String originFile, String targetFile, int threadCount) throws Exception {
this.originFileName = originFile;
this.targetFileName = targetFile;
this.originFile = new RandomAccessFile((originFile), FileCoper._ORIGIN_FILE_MODE);
this.targetFile = new RandomAccessFile((targetFile), FileCoper._TARGET_FILE_MODE);
this.threadCount = threadCount;
totalThreadCount = this.threadCount;
}
public void init(RandomAccessFile originFile, RandomAccessFile targetFile) throws Exception {
this.originFile = originFile;
this.targetFile = targetFile;
this.threadCount = 1;
totalThreadCount = this.threadCount;
}
public void init(RandomAccessFile originFile, RandomAccessFile targetFile, int threadCount) throws Exception {
this.originFile = originFile;
this.targetFile = targetFile;
this.threadCount = threadCount;
totalThreadCount = this.threadCount;
}
public static synchronized void finish() {
FileCoper.executedCount ++;
System.out.println("總線程【" + FileCoper.totalThreadCount + "】,已經(jīng)完成【" + FileCoper.executedCount + "】個線程的復制?。。?);
if (FileCoper.totalThreadCount == FileCoper.executedCount){
long time2 = System.currentTimeMillis();
System.out.println("花費時長："+(time2-time1));
System.out.println("所有【" + FileCoper.totalThreadCount + "】線程復制完成?。。?);
}
}
public void start() throws Exception {
if (this.originFile.length() == 0)
return;
if (this.threadCount == 0)
this.threadCount = 1;
// 設置目標文件大小
this.targetFile.setLength(this.originFile.length());
this.targetFile.seek(0);
this.originFile.seek(0);
time1 = System.currentTimeMillis();
System.out.println(this.originFile.length());
// 把文件分塊，每一塊有一對值：當前塊在文件中的起始位置和結束位置
long[][] splits = new long[this.threadCount][2];
long originFileLength = this.originFile.length();
int startPos = 0;
for (int i = 0; i < this.threadCount; i++) {
splits[i][0] = 0;
splits[i][1] = 0;
if (i == 0) {
splits[i][0] = 0;
splits[i][1] = originFileLength / this.threadCount;
} else if (i == this.threadCount - 1) {
// 注意：此處不能加1，如果加1，線程多文件就會出現(xiàn)亂碼
// splits[i][0] = startPos + 1;
splits[i][0] = startPos;
splits[i][1] = originFileLength;
} else {
// 注意：此處不能加1，如果加1，線程多文件就會出現(xiàn)亂碼
// splits[i][0] = startPos + 1;
splits[i][0] = startPos;
splits[i][1] = startPos + originFileLength / this.threadCount;
}
startPos += originFileLength / this.threadCount;
// System.out.println(splits[i][0] + " " + splits[i][1]);
Coper fc = new Coper("thread-" + i);
fc.init(this.originFile, this.targetFile, splits[i][0], splits[i][1]);
fc.setOriginFileName(this.originFileName);
fc.setTargetFileName(this.targetFileName);
fc.start();
}
}
public void startNew() throws Exception {
if (this.originFile.length() == 0)
return;
// 設置目標文件大小
this.targetFile.setLength(this.originFile.length());
this.targetFile.seek(0);
this.originFile.seek(0);
long startPosition;
long endPosition;
long block = this.originFile.length() / 1029;
if (block <= 1)
this.threadCount = 1;
for (int i = 0; i < this.threadCount; i++) {
// 定義每次轉移的長度
startPosition = i * 1029 * (block / this.threadCount);
endPosition = (i + 1) * 1029 * (block / this.threadCount);
if (i == (this.threadCount - 1))
endPosition = this.originFile.length();
Coper fc = new Coper("thread-" + i);
fc.init(this.originFile, this.targetFile, startPosition, endPosition);
fc.setOriginFileName(this.originFileName);
fc.setTargetFileName(this.targetFileName);
fc.start();
}
}
private class Coper extends Thread {
private String originFileName;
private String targetFileName;
private RandomAccessFile originFile;
private RandomAccessFile targetFile;
private String threadId;
private long startPosition;
private long endPosition;
private long blockCapacity;
public void setOriginFileName(String originFileName) {
this.originFileName = originFileName;
}
public void setTargetFileName(String targetFileName) {
this.targetFileName = targetFileName;
}
public Coper(String threadId) {
this.threadId = threadId;
}
public void init(RandomAccessFile originFile, RandomAccessFile targetFile, long startPosition, long endPosition) throws Exception {
this.originFile = originFile;
this.targetFile = targetFile;
this.startPosition = startPosition;
this.endPosition = endPosition;
this.blockCapacity = this.endPosition - this.startPosition;
}
public void run() {
// System.out.println(this.threadId + " 啟動，開始復制文件【" +
// this.originFileName + "】中的文件塊【" + this.startPosition + "," +
// this.endPosition + "】到目標文件【" + this.targetFileName + "】中...");
synchronized (this.originFile) {
try {
// 記錄當前拷貝的字節(jié)數(shù)
int copyCount = 0;
// 數(shù)據(jù)拷貝的啟示偏移量
long offSet = this.startPosition;
byte[] b = new byte[16 * 1024 * 1024];
// 動態(tài)設置一次讀取的字節(jié)數(shù)緩沖
long blockSize = 0;
while (copyCount < this.blockCapacity) {
this.originFile.seek(offSet);
if (this.blockCapacity - copyCount > 16 * 1024 * 1024)
blockSize = 16 * 1024 * 1024;
else
blockSize = this.blockCapacity - copyCount;
if (blockSize > this.blockCapacity - copyCount)
blockSize = this.blockCapacity - copyCount;
int count = this.originFile.read(b, 0, (int) blockSize);
synchronized (this.targetFile) {
try {
if (copyCount == 0)
this.targetFile.seek(offSet);
else
this.targetFile.seek(offSet + 1);
this.targetFile.write(b, 0, count);
} catch (IOException e) {
e.printStackTrace();
}
}
// 增加拷貝的字節(jié)數(shù)
copyCount += count;
// 拷貝其實【偏移量下移
offSet += count;
}
} catch (IOException e) {
e.printStackTrace();
}
}
// System.out.println(this.threadId + " 復制文件【" + this.originFileName
// + "】中的文件塊【" + this.startPosition + "," + this.endPosition +
// "】到目標文件【" + this.targetFileName + "】完成!");
// 通知主線程，當前線程完成復制工作
FileCoper.finish();
}
}
public static void main(String[] args) throws Exception {
FileCoper fc = new FileCoper();
fc.init("e:/InitialData_zhihuan.sql", "e:/InitialData_zhihuan2.sql", 30);
//fc.init("d:/ValueAdd_11.txt", "d:/ValueAdd_111.txt", 100);
// fc.init("D:\tools\music\做你的愛人.mp3", "d:/做你的愛人_5.mp3", 10);
//fc.init("E:\電影\最黑暗侵襲.rmvb", "d:/最黑暗侵襲_1.rmvb", 100);
/* // 讀入鍵盤輸入
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
// 文件來源
String originFile;
// 文件目標
String targetFile;
System.out.println("【源文件、目標文件、線程數(shù)】");
System.out.print("要復制的源文件：");
originFile = br.readLine();
System.out.print("文件復制到目標文件：");
targetFile = br.readLine();
System.out.print("切分線程數(shù)：");
int threadCount = Integer.parseInt(br.readLine());
fc.init(originFile, targetFile, threadCount);*/
// fc.startNew();
long time1 = System.currentTimeMillis();
fc.start();
long time2 = System.currentTimeMillis();
System.out.println(time2-time1);
}
}
您可能感興趣的文章:
相關文章
這篇文章主要介紹了mybatis的selectKey作用詳解，具有很好的參考價值，希望對大家有所幫助。以上為個人經(jīng)驗，希望能給大家一個參考，也希望大家多多支持腳本之家。</P><P>2022-01-01
這篇文章主要介紹了Java if-else 多重嵌套的優(yōu)化方式，具有很好的參考價值，希望對大家有所幫助。如有錯誤或未考慮完全的地方，望不吝賜教2022-02-02
SpringBoot中@Autowired注入service時出現(xiàn)循環(huán)依賴問題的解決方法
在Spring Boot開發(fā)過程中,@Autowired注入Service時出現(xiàn)循環(huán)依賴是一個常見問題,循環(huán)依賴指的是兩個或多個Bean相互依賴,形成閉環(huán),導致Spring容器無法正常初始化這些Bean,這里提供幾種解決Spring Boot中@Autowired注入Service時循環(huán)依賴問題的方法2024-02-02
這篇文章主要介紹了SpringBoot中使用 RabbitMQ的教程詳解,本文通過圖文并茂的形式給大家介紹的非常詳細，對大家的學習或工作具有一定的參考借鑒價值，需要的朋友可以參考下2020-11-11
Java內(nèi)存模型中的happens-before是什么？為什么會有這東西的存在？一個新東西肯定是上手先，但是等我們空下來回過頭來，我們還是需要去理解這些知識，只有這樣我才能深刻的記住，并且運用熟練。下來和小編來一起學習下2019-05-05
J2EE Servlet基礎在瀏覽器上運行HelloServlet的方法
這篇文章主要介紹了J2EE Servlet基礎在瀏覽器上運行HelloServlet的方法,本文給大家介紹的非常詳細，對大家的學習或工作具有一定的參考借鑒價值，需要的朋友可以參考下2020-10-10
DOM解析XML報錯Content is not allowed in prolog解決方案詳解
這篇文章主要介紹了DOM解析XML報錯解決方案詳解,文中通過示例代碼介紹的非常詳細，對大家的學習或者工作具有一定的參考學習價值,需要的朋友可以參考下2020-10-10
測試代碼如下：2009-06-06
常常遇到數(shù)組排序的問題，下面提供二個java的arraylist排序示例,需要的朋友可以參考下2014-03-03
這篇文章主要介紹了Java 正確終止線程的方法，幫助大家更好的理解和學習java 多線程的相關知識，感興趣的朋友可以了解下2020-12-12