?.class文件内的代码所在的文件的路径默认

1 举例1：读取项目根目录下的数据。 2 private static void readRoot() throws FileNotFoundException, IOException { 3     BufferedReader br = new BufferedReader(new FileReader( 4 new File("jnb.txt")));         5            String line = br.readLine(); 6            System.out.println(line); 7 } 8 举例2：读取和class文件同目录的资源数据。 9 private static void readClassPath() throws FileNotFoundException,10             IOException {11         URL url= SoreceReader.class.getResource("jnb.txt");12         String path = url.getPath();13         System.out.println(path);14         BufferedReader br = new BufferedReader(15 new FileReader(new File(path)));    16         String line = br.readLine();17         System.out.println(line);18 }

 

举例3：读取在src目录的资源数据。//文件放在上几级目录下private static void readBin() throws FileNotFoundException, IOException {        URL url= SoreceReader.class.getResource("../../../jnb.txt");        String path = url.getPath();        System.out.println(path);        BufferedReader br = new BufferedReader(new FileReader(new File(path)));            String line = br.readLine();        System.out.println(line);}可以直接返回一个指定资源的输入流对象。public static void main(String[] args) throws Exception{    InputStream in = SoreceReader.class.getResourceAsStream("../../../jnb.txt");           BufferedReader br = new BufferedReader(new InputStreamReader(in));        String line = br.readLine();        System.out.println(line);}getResourceAsStream VS getResourcegetResourceAsStream直接返回了流对象因此无法获取资源的信息。getResource直接返回的是资源的绝对路径，那么封装File可以快速的获取资源的信息。所有在文件下载的时候一般使用该方法。