try {
            File file = new File("E:\\1.txt");
            boolean newFile = file.createNewFile();//创建一个新的文件
            System.out.println(newFile? "创建成功":"创建失败");
            File file1 = new File("E:\\1_java");
            boolean newFile1 = file1.mkdir();//创建一个新的文件夹
            System.out.println(newFile1? "文件夹创建成功":"文件夹创建失败");
            File file3 = new File("E:\\2_java\\3_java");
            boolean newFile2= file3.mkdirs();//创建一个新的多级文件夹
            System.out.println(newFile2? "多级文件夹创建成功":"多级文件夹创建失败");
        } catch (IOException e) {
            e.printStackTrace();
        }

        File file = new File("E:\\1.txt");
        boolean flag1 = file.delete();//删除一个新的文件
        System.out.println(flag1 ? "删除成功":"删除失败");
        File file = new File("E:\\1.txt");
        boolean exists = file.exists();
        if(exists){
            System.out.println("已存在！");
        }else{
            file.mkdir();
        }
        System.out.println(file.getName());
        System.out.println(file.getPath());
        System.out.println(file.getAbsolutePath());
        File file1 = new File("E:\\2.txt");
        file1.createNewFile();
        System.out.println(file1.length());//字节为单位
//递归找出某个文件夹下所有文件
    public static void showFiles(String pathname){
        File f1 = new File(pathname);
        boolean directory = f1.isDirectory();
        if(directory){
            File[] files = f1.listFiles();
            if(files != null){
                for ( File f : files){
                    showFiles(f.getPath());
                }
            }
        }else{
            String path = f1.getPath();
            System.out.println("普通文件-----" + path);
        }
    }

       //在文件和程序之间铺设管道
        //FileInputStream fis = new FileInputStream("E:\\2.txt");
        File file = new File("E:\\2.txt");
        if(file.exists() && file.length() > 0){
            FileInputStream fis = new FileInputStream(file);
//            int ch = fis.read();//一次只读一个字节
//            System.out.println("ch = " + (char)ch);
            int ch = 0;
            while((ch = fis.read()) != -1){
                System.out.println((char)ch);
            }
            fis.close();
        }

FileInputStream fis = new FileInputStream("E:\\1.txt");
        BufferedInputStream bis = new BufferedInputStream(fis);
        byte[] car = new byte[1024];
        int len = 0;
        while((len = bis.read(car)) != -1){
            System.out.println(len);
        }
 

        String data = "haha";
        byte[] bytes = data.getBytes();
        //append为true,追加;false，覆盖
        FileOutputStream fos = new                          FileOutputStream("E:\\1.txt",true);
        fos.write(bytes);
        fos.close();

        File file = new File("E:\\2.txt");
        if(file.exists() && file.length() > 0){
            FileInputStream fis = new FileInputStream(file);
            FileOutputStream fos = new FileOutputStream("E:\\1.txt",true);
//            int ch = fis.read();//一次只读一个字节
//            System.out.println("ch = " + (char)ch);
            int ch = 0;
            while((ch = fis.read()) != -1){
                fos.write(ch);
            }
            fos.close();
            fis.close();
        }

        FileInputStream fis = new FileInputStream("E:\\1.txt");
        BufferedInputStream bis = new BufferedInputStream(fis);
        FileOutputStream fos = new FileOutputStream("E:\\2.txt");
        BufferedOutputStream bos = new BufferedOutputStream(fos);
        byte[] car = new byte[1024];
        int len = 0;
        while((len = bis.read(car)) != -1){
            bos.write(car,0,len);
        }
        bos.close();
        bis.close();
        fis.close();
        fos.close();

FileReader fr = new FileReader("E:\\1.txt");
        char[] car = new char[1024];
        int len = 0;
        while((len = fr.read(car)) != -1){
            System.out.println(len);
            String str = new String(car,0,len);
            System.out.println(str);
        }
        fr.close(); 

        FileReader fr = new FileReader("E:\\1.txt");
        FileWriter fw = new FileWriter("E:\\2.txt");
        char[] car = new char[1024];
        int len = 0;
        fw.write("中国");
        while((len = fr.read(car)) != -1){
            System.out.println(len);
            fw.write(car,0,len);
        }
        fw.close();
        fr.close();