把指定文件夹中的所有指定后缀的文件转移到一个文件中（GC引入第三方库必备）

TransferAllIntoOne.java

import java.io.File;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;

public class TransferAllIntoOne {
    public static void main(String[] args) throws Throwable {
        File file = new File(".");
        File to = new File("./Index.js");
        iterateAllFile(file, to);
    }

    public static void iterateAllFile(File file,File to) throws Throwable {
        if (file.isDirectory()) {            
            File[] childrens = file.listFiles();
            for (File child : childrens) {
                iterateAllFile(child, to);
            }
        } else {
            if (file.getName().endsWith(".ts")) {
                BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));
                BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(to, true));

                bos.write(bis.readAllBytes());

                bos.close();
                bis.close();
            }
        }
    }
}