javase文件切割及融合

Posted 2020-09-13 艺海浮台

  1 package com.split;
  2 
  3 import java.io.File;
  4 import java.io.FileInputStream;
  5 import java.io.FileNotFoundException;
  6 import java.io.FileOutputStream;
  7 
  8 public class FileSplit {
  9 
 10     public static void main(String[] args) {
 11         // TODO Auto-generated method stub
 12         //String file = "D:\\arch\\d.jpg";
 13         String file="D:\\arch\\b.txt";
 14         split(file);
 15         String s1="D:\\arch\\b.txtpart-0";
 16         String s2="D:\\arch\\b.txtpart-1";
 17         String s3="D:\\arch\\b.txtpart-2";
 18         fuse(s1,s2,s3);
 19 
 20     }
 21 /**
 22  * 文件融合
 23  * @param srcFile
 24  */
 25 public static void fuse(String... srcFile ){
 26     for (String string : srcFile) {
 27         fusion(string);
 28     }
 29 }
 30     private static void fusion(String file) {
 31         File f=new File(file);
 32         FileInputStream fis=null;
 33         FileOutputStream fos=null;
 34         try {
 35             if(f.exists()){
 36                 if(f.isFile()){
 37                     fis=new FileInputStream(f);
 38                     //string="D:\\arch\\b.txtpart-0"
 39                     String srcPath=f.getAbsolutePath();
 40                     String sep="";
 41                     if(srcPath.contains("\\")){
 42                         sep="\\";
 43                     }
 44                     int index=srcPath.lastIndexOf(sep);
 45                     
 46                     //String s=srcPath.substring(0, (srcPath.length()-6));
 47                     //获取最后一个名字的字符串
 48                     String s=srcPath.substring(0, index+f.getName().length());
 49                     fos=new FileOutputStream(new File(s),true);
 50                     byte[] buf=new byte[1024];
 51                     int len=0;
 52                     while((len=fis.read(buf))!=-1){
 53                         fos.write(buf, 0, len);
 54                         fos.close();
 55                     }
 56                 }
 57             }
 58             fis.close();
 59         } catch (Exception e) {
 60             // TODO: handle exception
 61         }
 62 }
 63 /**
 64  * 文件的切割
 65  */
 66     public static void split(String srcfile) {
 67 
 68         File f = new File(srcfile);
 69         FileOutputStream fos = null;
 70         try {
 71             FileInputStream fis = new FileInputStream(f);
 72             // 获取文件大小
 73             int len = (int) f.length();
 74             // 切割块数
 75             int blocks = 3;
 76             // 每块的大小
 77             int blocksSize = len / blocks;
 78             int len0 = 0;
 79             byte[] buf = new byte[1024];
 80             for (int i = 0; i < blocks; i++) {
 81                 //根据源目录创建目标文件对象
 82                 fos = new FileOutputStream(new File(f.getParent(), f.getName() + "part-" + i));
 83                 // 如果是最后一块
 84                 if (i == (blocks - 1)) {
 85                     while ((len0 = fis.read(buf)) != -1) {
 86                         fos.write(buf, 0, len0);
 87                     }
 88                     fos.close();
 89                 }
 90                 // 不是最后一块
 91                 else {
 92                     // 不足缓冲区
 93                     if (blocksSize <=buf.length) {
 94                         buf = new byte[blocksSize];
 95                         fis.read(buf);
 96                         fos.write(buf);
 97                         fos.close();
 98                     }
 99                     // 超过缓冲区
100                     else {
101                         int count = blocksSize / buf.length;
102                         for (int j = 0; j < count; j++) {
103                             // 最后一次读取
104                             if (j == (count - 1)) {
105                                 if(blocksSize%buf.length !=0){
106                                     buf = new byte[buf.length + (blocksSize % buf.length)];
107                                     fis.read(buf);
108                                     fos.write(buf);
109                                     fos.close();
110                                 }
111                             } 
112                             else {
113                                 fis.read(buf);
114                                 fos.write(buf);
115                             }
116                         }
117                     }
118                 }
119             }
120             fis.close();
121         } catch (Exception e) {
122             // TODO Auto-generated catch block
123             e.printStackTrace();
124         }
125     }
126 }