1、文件操作
public static void main(String args[]) throws IOException {
        String dirPath = "d:/aaa/bbb/";
        File fileDirPath = new File(dirPath);
        System.out.println(fileDirPath.exists());
        //判断文件目录是否存在
        if (!fileDirPath.exists()) {
            if (!fileDirPath.isDirectory()) {
                fileDirPath.mkdir();
            }
        }
        String filePath = dirPath + "/4244.txt";
        System.out.println(filePath);
        File file = new File(filePath);
        //判断文件是否存在
        if (!file.exists()) {
            file.createNewFile();
        }
        //写数据到文件
        BufferedWriter out = new BufferedWriter(new FileWriter(file));
        out.write("55555fsfddasf55");
        out.write("aaaaaaaa");
        out.close();
        System.out.println("文件创建成功！");
//        System.out.println(delAllFile(dirPath));
        //删除文件
//        file.delete();
        //读取文件
        FileInputStream fileInputStream = new FileInputStream(filePath);
        int i ;
        byte[] bytes = new byte[1024];
        while ((i = fileInputStream.read(bytes))!= -1) {
            String s = new String(bytes);
            System.out.println(s);
        }
        fileInputStream.close();
    }

<dependency>
            <groupId>org.xeustechnologies</groupId>
            <artifactId>jtar</artifactId>
            <version>1.1</version>
        </dependency>

/**
             * 文件打成tar
             */
            //原来的文件地址
            FileOutputStream dest;
            //打包后的tar地址
            TarOutputStream out;
            try {
                dest = new FileOutputStream(tarPath);
                out = new TarOutputStream(new BufferedOutputStream(dest));
                File f = new File(txtPath);
                out.putNextEntry(new TarEntry(f, f.getName()));
                BufferedInputStream origin = new BufferedInputStream(new FileInputStream(f));
                int count;
                byte data[] = new byte[2048];
                while ((count = origin.read(data)) != -1) {
                    out.write(data, 0, count);
                }
                out.flush();
                origin.close();
                out.close();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }