Java实现文件分割与合并

package com.xhh.util;

import java.io.*;

/**
 * 文件分割的方法
 * @param SrcFilePath 指定分割的文件路径
 * @param SingleGoalFileSize 分割文件的个数
 * @param GoalFileDirectory 分割之后的路径
 */
public class Split{
 public static void Split(String SrcFilePath,int SingleGoalFileSize,String GoalFileDirectory){
 //SingleGoalFileSize 单位：MB ，校验路径和目录
 if("".equals(SrcFilePath) || SrcFilePath == null || "".equals(GoalFileDirectory) || GoalFileDirectory == null){
  System.out.println("分割失败!");
  return;
 }

 File SrcFile = new File(SrcFilePath); //新建文件
 long SrcFileSize = SrcFile.length();//源文件的大小
 long SingleFileSize = 1024 * 1024 * SingleGoalFileSize;//分割后的单个文件大小(单位字节)

 int GoalFileNum = (int)(SrcFileSize/SingleFileSize); //获取文件的大小
 GoalFileNum = SrcFileSize % SingleFileSize == 0 ? GoalFileNum : GoalFileNum + 1; //计算总的文件大小

 int x1 = SrcFilePath.lastIndexOf("\\"); //获取文件路径的分隔符位置
 int x2 = SrcFilePath.lastIndexOf("."); //获取文件的后缀位置

 String SrcFileName = SrcFilePath.substring(x1,x2); //截取文件名

 FileInputStream fis = null;
 BufferedInputStream bis = null;
 byte bytes[] = new byte[1024 * 1024];//每次读取文件的大小
 int len = -1;

 try{ 
  fis = new FileInputStream(SrcFilePath); //新建输入流对象
  bis = new BufferedInputStream(fis); 

  for(int i = 0; i < GoalFileNum; i++){
   //分割后的单个文件完整路径名
   String CompleteSingleGoalFilePath = GoalFileDirectory + File.separator + SrcFileName + "-" + i + SrcFilePath.substring(x2);
   FileOutputStream fos = new FileOutputStream(CompleteSingleGoalFilePath);
   BufferedOutputStream bos = new BufferedOutputStream(fos); //包装
   int count = 0;
   while((len = bis.read(bytes))!=-1){
    bos.write(bytes,0,len);//从源文件读取规定大小的字节数写入到单个目标文件中
    count += len;
    if(count >= SingleFileSize)
     break;
   }
   bos.flush();
   bos.close();
   fos.close();
  }
   System.out.println("分割成功!");
 }catch (FileNotFoundException e){
  e.printStackTrace();
 } catch (IOException e) {
  e.printStackTrace();
 }finally {
  try{
   if(bis != null) {
    bis.close();
   }

   if(fis != null) {
    fis.close();
   }
  } catch (IOException e) {
   e.printStackTrace();
  }
 }
}
}

package com.xhh.util;

import java.io.*;

public class Merge { 
/**
 * @param SingleFilePath 
 * @param GoalFileDirectory 
 */
 public static void Merge(String SingleFilePath[],String GoalFileDirectory){
  if(GoalFileDirectory == null || "".equals(GoalFileDirectory)){
   System.out.println("合并失败!");
   return;
  }

  int x1 = SingleFilePath[0].lastIndexOf("\\");
  int x2 = SingleFilePath[0].lastIndexOf(".");
  String GoalFileName = SingleFilePath[0].substring(x1,x2);

  //合并后的完整路径名
  String CompleteGoalFilePath = GoalFileDirectory + File.separator + GoalFileName.substring(0,GoalFileName.lastIndexOf("-"))+ SingleFilePath[0].substring(x2);

  byte bytes[] = new byte[1024 * 1024];//每次读取文件的大小
  int len = -1;

  FileOutputStream fos = null;//将数据合并到目标文件中
  BufferedOutputStream bos = null;//使用缓冲字节流写入数据
  try{
    fos = new FileOutputStream(CompleteGoalFilePath);
    bos = new BufferedOutputStream(fos);

   for(int i = 0; i < SingleFilePath.length; i++){
    if(SingleFilePath[i] == null || "".equals(SingleFilePath)){
     System.exit(0);
    }

    FileInputStream fis = new FileInputStream(SingleFilePath[i]);//从分割后的文件读取数据
    BufferedInputStream bis = new BufferedInputStream(fis);//使用缓冲字节流读取数据
    while ((len = bis.read(bytes))!= -1)
     bos.write(bytes, 0, len);

    bis.close();
    fis.close();
   }
   System.out.println("合并成功!");
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  }finally {
   try {
    if (bos != null)
     bos.close();

    if(fos != null)
     fos.close();

   } catch (IOException e) {
    e.printStackTrace();
   }
  }
 }

/**
 * 测试
 * @param args
 */
public static void main(String[] args) {
//  Split("D:\\qycache\\download\\dpx\\dpx3.qvs", 10, "D:\\qycache\\download\\hhhh");//
//     Split(SrcFilePath, SingleGoalFileSize, GoalFileDirectory);
//     SrcFilePath 指定分割的文件路径  SingleGoalFileSize 分割文件的个数  GoalFileDirectory 分割完成之后的路径     
  String[] MergeFilePath = new String[5];//分割出来的文件个数
     for(int i = 0; i < MergeFilePath.length; i++)
       MergeFilePath[i] = new String("D:\\qycache\\download\\hhhh\\dpx3-" + i + ".qsv");//想要合并的文件路径
       Merge(MergeFilePath,"D:\\qycache\\download\\jjjj");//合并之后保存的路径
 }