java-文件合并

package merge;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;

public class Merge {
    public static void main(String[] args) throws Exception {
        String directory = "C:\\Users\\Administrator\\Desktop\\zz";
        File path = new File(directory);
        File[] files = path.listFiles();
        ArrayList<byte[]> list = new ArrayList<>();

        FileOutputStream fileOutputStream = new FileOutputStream("C:\\Users\\Administrator\\Desktop\\yy\\test.pdf", true);
        BufferedOutputStream outputStream = new BufferedOutputStream(fileOutputStream);

        for (int i = 0; i < files.length; i++) {
            String st = directory+"\\"+"test.part"+i;
Path pt = Paths.get(st);
byte[] bt = Files.readAllBytes(pt);
            list.add(bt);
        }
        System.out.println();
        for (int i = 0; i <list.size() ; i++) {
            outputStream.write(list.get(i));
        }
    }

}