一：

题目：

写一个方法,将feige.exe文件分割为每份1MB大小的若干份(最后一份可以不满1MB),
存储在一个temp的文件夹中(每份文件名自己定义,例如1.temp 2.temp), 
然后再写一个方法,将temp文件夹中的若干份合并为一个文件fg.exe

代码：

main

package com.ffyc.javaIO.zy.zy1;import java.io.*;public class T3 { public static void main(String[] args) throws IOException {File file1 = new File("D:/feige.exe");resolve(file1);compound(file1);} 
}

分割

 
public static void resolve(File file) throws IOException {FileInputStream in = new FileInputStream(file);BufferedInputStream bin = new BufferedInputStream(in);File f = new File("D:/temp");if(!f.exists()){f.mkdir();}int size = 0;byte[] bytes = new byte[1024*1024];int i = 0;while ((size = bin.read(bytes)) != -1){i++;FileOutputStream out = new FileOutputStream("D:/temp/"+i+".temp");BufferedOutputStream bout = new BufferedOutputStream(out);bout.write(bytes, 0, size);bout.flush();bout.close();}bin.close();
}

合并

public static void compound(File file) throws IOException {FileOutputStream out = new FileOutputStream("D:/fg.exe");File f = new File("D:/temp");int num = f.list().length;for (int i = 1; i <= num; i++) {FileInputStream in = new FileInputStream("D:/temp/"+i+".temp");byte[] bytes = new byte[1024];int size = 0;while ((size = in.read(bytes)) != -1) {out.write(bytes, 0, size);}in.close();}out.close();}

运行 

二：

题目：

完善文件分割,将1MB文件分多次读写

思路：

文件的大小  file.length   总共的字节数  
每份的大小  1MB
总共有多少份 = 总共的字节数/每份大小+1
fori 知道输入多少个文件了
FileOutputStream out = new FileOutputStream("D:/temp/"+i+".temp");
int size = 0;
byte[] bytes = new byte[1024];
int i = 0;
while ( ) 

代码：

package com.ffyc.javaIO.zy.zy2;import java.io.*;public class T3 {public static void main(String[] args) throws IOException {File f = new File("D:/temp");if(!f.exists()){f.mkdir();}File file = new File("D:/feige.exe");FileInputStream in = new FileInputStream(file);//文件长度  字节数量long len = (file.length()%1024%1024)==0?(file.length()/1024/1024):(file.length()/1024/1024)+1;for (int i = 0; i < len; i++) {int sum = 0;int size = 0;byte[] bytes = new byte[1024];FileOutputStream out = new FileOutputStream("D:/temp/"+i+".temp");while ((size = in.read(bytes)) != -1){sum+=size;out.write(bytes,0,size);//记录有没有1mbif(sum>1024*1024){break;}}out.close();}in.close();}
}

运行