//需要所指目录下确有一个文件供拆分

//多余的另成一个文件

package File;

import java.util.*;

import java.io.*;

public class TestStrem{

public static void main(String[] args) {

int eachSize=100*1024//100k;

File scrFile = new File("d:/javaha/gys.txt");

splitFile(scrFile,eachSize);

}

public static void splitFile(File scrFile,int eachSize) {

if(0==scrFile.length())

throw new RuntimeException("文件长度为0，不可拆分");

byte[] fileConent = new byte[(int)scrFile.length()];

try {

FileInputStream fis =new FileInputStream(scrFile);

fis.read(fileConent);

fis.close();

}

catch(IOException e) {

e.printStackTrace();

}

int fileNumber;

if(fileConent.length % eachSize==0)

fileNumber =(int)(fileConent.length / eachSize);

else

fileNumber =(int)(fileConent.length / eachSize )+ 1;

for(int i=0;i

String eachFilename=scrFile.getName()+"-"+ i;

File eachFile =new File(scrFile.getParent(),eachFilename);

byte[] eachContent;

if(i!=fileNumber-1)

eachContent =Arrays.copyOfRange(fileConent, eachSize*i , eachSize);

else

eachContent =Arrays.copyOfRange(fileConent, eachSize*i , fileConent.length);

try {

FileOutputStream fos =new FileOutputStream(eachFile);

fos.write(eachContent);

fos.close();

System.out.format("输出子文件%s,其大小是%d字节",eachFile.getAbsolutePath(),eachFile.length());

}catch(IOException e) {

e.printStackTrace();

}

}

}

}

//合并，

package stream;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import javax.security.auth.DestroyFailedException;

public class TestStream {

public static void main(String[] args) {

murgeFile("d:/", "eclipse.exe");

}

/**

* 合并的思路，就是从eclipse.exe-0开始，读取到一个文件，就开始写出到 eclipse.exe中，直到没有文件可以读

* @param folder

* 需要合并的文件所处于的目录

* @param fileName

* 需要合并的文件的名称

* @throws FileNotFoundException

*/

private static void murgeFile(String folder, String fileName) {

try {

// 合并的目标文件

File destFile = new File(folder, fileName);

FileOutputStream fos = new FileOutputStream(destFile);

int index = 0;

while (true) {

//子文件

File eachFile = new File(folder, fileName + "-" + index++);

//如果子文件不存在了就结束

if (!eachFile.exists())

break;

//读取子文件的内容

FileInputStream fis = new FileInputStream(eachFile);

byte[] eachContent = new byte[(int) eachFile.length()];

fis.read(eachContent);

fis.close();

//把子文件的内容写出去

fos.write(eachContent);

fos.flush();

System.out.printf("把子文件 %s写出到目标文件中%n",eachFile);

}

fos.close();

System.out.printf("最后目标文件的大小：%,d字节" , destFile.length());

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}