主要应用IO的RandomAccessFile(听说断点续传也是用它实现)

import java.io.*;

class Fen{
String fileName;
int size;

Fen(String fileName,String size){
this.fileName = fileName;
this.size = Integer.parseInt(size)*1024;
}

public void cut()throws Exception{
int maxx = 0;
File inFile = new File(fileName);

int fileLength = (int)inFile.length(); //取得文件的大小
int value; //取得要分割的个数

RandomAccessFile inn = new RandomAccessFile(inFile,"r");//打开要分割的文件


value = fileLength/size;

int i=0;
int j=0;

//根据要分割的数目输出文件
for (;j File outFile = new File(inFile.getName()+j+"zzii");
RandomAccessFile outt= new RandomAccessFile(outFile,"rw");
maxx+=size;
for (;i outt.write(inn.read());
}
outt.close();
}
File outFile = new File(inFile.getName()+j+"zzii");
RandomAccessFile outt= new RandomAccessFile(outFile,"rw");
for(;i
outt.write(inn.read());
}
outt.close();

inn.close();
}
}


class He{
String fileName;
String filterName;

He(String fileName,String filterName){
this.fileName = fileName;
this.filterName = filterName;
}


public void unite()throws Exception{
String [] tt;
File inFile = new File("."); //在当前目录下的文件
File outFile = new File(fileName); //取得输出名
RandomAccessFile outt= new RandomAccessFile(outFile,"rw");

//取得符合条件的文件名
tt = inFile.list(new FilenameFilter(){
public boolean accept(File dir,String name){
String rr = new File(name).toString();
return rr.endsWith(filterName);
}
});
//打印出取得的文件名
for (int i = 0;i System.out.println(tt[i]);
}

//打开所有的文件再写入到一个文件里
for(int i=0;i inFile = new File(tt[i]);
RandomAccessFile inn= new RandomAccessFile(inFile,"r");
int c;
while((c=inn.read())!=-1)
outt.write(c);
}

outt.close();
}
}


public class test{
public static void main(final String [] args)throws Exception{

if(args.length==0){
print();
return;
}
if(args[0].equals("-c")){
Fen cutt = new Fen(args[1],args[2]);
cutt.cut();
}
else if (args[0].equals("-r")){
He hee = new He(args[1],args[2]);
hee.unite();
}
else
print();

}

public static void print(){
System.out.println("usage:\n分: java test -c file1 size(单位为K)\n合 java test -r file2 zzii(我设置的方便标识)");
}
}