java读写磁盘文件

字符流读写文本文件（txt，csv等）

/**
 * 字符流写文件
 */
private void writeBufferedWriter() throws IOException {
    String path = "/data/output.txt";
    try (BufferedWriter bw = new BufferedWriter(new FileWriter(path))) {
        bw.write("我是一个文本文件。");
    }
}

/**
 * 字符流读文件
 */
private void readBufferedReader() throws IOException {
    
	String path = "/data/output.txt";
	
	// 逐个char读取 （不推荐）
    try (BufferedReader br = new BufferedReader(new FileReader(path))) {
        int c;
        while ((c = br.read()) != -1) {
            System.out.print((char) c);
        }
    }

    // 行读取 bufferedReader.readLine()
    try (BufferedReader br = new BufferedReader(new FileReader(path))) {
        String line;
        while ((line = br.readLine()) != null) {
            System.out.print(line);
        }
    }

    // 块读取 new char[1024]
    try (BufferedReader br = new BufferedReader(new FileReader(path))) {
        char[] buf = new char[1024];
        int length;
        while ((length = br.read(buf)) != -1) {
            String str = new String(buf, 0, length);
            System.out.print(str);
        }
    }
}

字节流读写音视频、二进制、docx\xlsx\pdfx等文件，文本文件也可以但不推荐

/**
 * 字节流写文件
 */
private void writeBufferedOutputStream() throws IOException {
	String path = "/data/output.txt";
	String content = "文件内容";
	// try-with-resources语句‌：这是一种推荐的方法，可以确保在try语句块执行完毕后自动关闭流
    try (BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(path))) {
        byte[] bytes = content.getBytes();
        bos.write(bytes);
    }
}

/**
 * 字节流读文件
 */
private void readBufferedInputStream() throws IOException {
	String path = "/data/input.txt";
	// try-with-resources语句‌：这是一种推荐的方法，可以确保在try语句块执行完毕后自动关闭流
    try (BufferedInputStream bis = new BufferedInputStream(new FileInputStream(path))) {
        byte[] buf = new byte[1024];
        int length;
        while ((length = bis.read(buf)) != -1) {
            // 非字符文件，转换出来乱码
			String str = new String(buf, 0, length);
            System.out.print(str);
        }
    }
}