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)");

}

}