import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.File;

import java.io.FilenameFilter;

import java.io.BufferedInputStream;

import java.io.BufferedOutputStream;

import java.io.IOException;

public class Merge{

public static void main(String[] args){

File dir = new File(".");

File[] files = dir.listFiles(new FilenameFilter(){

@Override

public boolean accept(File dir, String name){

return name.contains("_part_");

}

});

if(files.length < 1){

System.err.println("No valid part files.");

return;

}

BufferedInputStream bis = null;

BufferedOutputStream bos = null;

try{

String temp = files[0].getName();

File mergeFile = new File("Merge_" + temp.substring(0, temp.indexOf("_")));

bos = new BufferedOutputStream(new FileOutputStream(mergeFile));

for(File file: files){

bis = new BufferedInputStream(new FileInputStream(file));

int read;

while((read = bis.read())!=-1){

bos.write(read);

}

bis.close();

}

}catch(IOException ioe){

ioe.printStackTrace();

}finally{

if(bis!=null){

try{

bis.close();

}catch(IOException ioe){

ioe.printStackTrace();

}

}

if(bos!=null){

try{

bos.close();

}catch(IOException ioe){

ioe.printStackTrace();

}

}

}

}

}