java 流操作对文件的分割和合并的实例详解

package com.dufy.file;  import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.SequenceInputStream; import java.util.ArrayList; import java.util.Collections; import java.util.Enumeration; import java.util.List;  public class TestFileCutUnion {    public static void main(String[] args) throws IOException {          String fSrc = "D:/1.jpg";//源文件的目录     String fDir = "D:/1";//目标文件的目录     String fTemp = "D:/2";//暂存文件的目录     File srcFile = new File(fSrc);     File dirFile = new File(fDir);     File tempFile = new File(fTemp);     String fileName = srcFile.getName();//获取文件的名称     cutFile(srcFile,tempFile);//调用分割方法     unionFile(dirFile,tempFile,fileName);//调用合并方法             }            public static void cutFile(File srcFile, File tempFile) throws IOException {     //读取源地址文件     FileInputStream fis = new FileInputStream(srcFile);     FileOutputStream fos = null;     //是否为文件，不是就创建     if(!tempFile.isFile()){       tempFile.mkdirs();     }        byte[] b = new byte[100];     int len =0;     int count = 0;     while((len=fis.read(b)) != -1){       int num = count++;       //写入暂存地址目录中       fos = new FileOutputStream(new File(tempFile, num+".part"));       fos.write(b, 0, len);            }     fos.flush();     fos.close();     fis.close();          System.out.println("分割完成！");   }      public static void unionFile(File dirFile, File tempFile, String fileName) throws IOException {     //判断目标地址是否存在，不存在则创建     if(!dirFile.isFile()){       dirFile.mkdirs();     }     List<FileInputStream> list = new ArrayList<FileInputStream>();     //获取暂存地址中的文件     File[] files = tempFile.listFiles();          for (int i = 0; i < files.length; i++) {       //用FileInputStream读取放入list集合       list.add(new FileInputStream(new File(tempFile, i+".part")));     }     //使用 Enumeration（列举） 将文件全部列举出来     Enumeration<FileInputStream> eum = Collections.enumeration(list);     //SequenceInputStream合并流 合并文件     SequenceInputStream sis = new SequenceInputStream(eum);     FileOutputStream fos = new FileOutputStream(new File(dirFile, fileName));     byte[] by = new byte[100];     int len;     while((len=sis.read(by)) != -1){       fos.write(by, 0, len);     }     fos.flush();     fos.close();     sis.close();     System.out.println("合并完成！");   } }