Java.io.字节流

//字节流，向文件写入字符串
	public static void main(String[] args) throws Exception {
		//输出到哪里
		File file=new File("d:"+File.separator+"test.txt");
		
		OutputStream outputStream = new FileOutputStream(file);
		String str="1234qwer";//写入的字符串
		
		byte[] bytes = str.getBytes();//只能输入byte数组，所以先转为byte数组
		
		outputStream.write(bytes);//写入
		outputStream.close();
	}

// 字节流，读取文件的字符串
	public static void main(String[] args) throws Exception {
		//读取哪个文件
		String path = "d:" + File.separator + "test.txt";
		File file = new File(path);

		InputStream fileInputStream = new FileInputStream(file);

		byte[] bs = new byte[1000];//所有的内容读到这个数组
		
		int read_len = fileInputStream.read(bs);//读取到的文件大小
		fileInputStream.close();

		System.out.println("读取的长度" + read_len);
		System.out.println(new String(bs, 0, read_len));//输出到控制台

	}