Java中获取资源文件的方法总结

public void doGet(HttpServletRequest request, HttpServletResponse response) 
			throws ServletException, IOException {
		PrintWriter pw = response.getWriter();
		ServletContext context = this.getServletContext();
		/**
		 * 获取不同路径下的资源文件
		 * servletContext是相对于项目的根目录的，这里为WebContent
		 */
		InputStream  inputA = context.getResourceAsStream("/a.txt");
		InputStream inputB = context.getResourceAsStream("/WEB-INF/classes/cn/zydev/b.txt");
		InputStream inputC = context.getResourceAsStream("/WEB-INF/classes/c.txt");
		
		/**
		 * 获取真实的磁盘路径
		 */
		String realPath = context.getRealPath("/WEB-INF/classes/c.txt");
		
		/**
		 * 获取指定目录下的文件（包括目录,深度为1级）
		 */
		Set<String> rsc = context.getResourcePaths("/WEB-INF");
		String a = IOUtils.toString(inputA);
		String b = IOUtils.toString(inputB);
		String c = IOUtils.toString(inputC);
		pw.print(a+"<br/>");
		pw.print(b+"<br/>");
		pw.print(c+"<br/>");
		pw.print(realPath+"<br/>");
		pw.println(rsc);
	}

protected void doGet(HttpServletRequest request, HttpServletResponse response) 
			throws ServletException, IOException {
		PrintWriter pw = response.getWriter();
		/**
		 * ClassLoader是相对于classes参照的
		 * 第一个斜杠可以不写，也可以写成./(熟悉Linux的应该很清楚）
		 */
		ClassLoader cl = this.getClass().getClassLoader();
		InputStream inputA = cl.getResourceAsStream("/../../a.txt");
		InputStream inputB = cl.getResourceAsStream("/cn/zydev/b.txt");
		InputStream inputC = cl.getResourceAsStream("/c.txt");
		String a = IOUtils.toString(inputA);
		String b = IOUtils.toString(inputB);
		String c = IOUtils.toString(inputC);
		pw.print(a+"<br/>");
		pw.print(b+"<br/>");
		pw.print(c+"<br/>");
	}

protected void doGet(HttpServletRequest request, HttpServletResponse response) 
			throws ServletException, IOException {
		PrintWriter pw = response.getWriter();
		Class cs = this.getClass();
		//不加斜杠表示相对于class（CServlet）
		InputStream inputA = cs.getResourceAsStream("../../../../a.txt");
		InputStream inputB = cs.getResourceAsStream("b.txt");
		//加斜杠，相对于classes
		InputStream inputC = cs.getResourceAsStream("/c.txt");
		String a = IOUtils.toString(inputA);
		String b = IOUtils.toString(inputB);
		String c = IOUtils.toString(inputC);
		pw.print(a+"<br/>");
		pw.print(b+"<br/>");
		pw.print(c+"<br/>");
	}