获取请求的参数值

当请求的参数有多个值时，使用getParameterValues()方法

 protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("==========doGet请求==============");
        System.out.println("获取请求参数name：" + req.getParameter("username"));
        System.out.println("获取请求参数password：" + req.getParameter("password"));
        String[] hobbies = req.getParameterValues("hobby");
        System.out.println("获取请求参数hobby：" + Arrays.asList(hobbies));
    }

在Post请求中，可能会出现中文乱码问题
req. setCharacterEncoding(); 方法可以解决中文乱码问题，但需要在获取请求参数之前调用才有效

protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("==========doPost请求==============");
        //设置请求体的字符集为UTF-8，从而解决post 请求的中文乱码问题
        //需要在获取请求参数之前调用才有效
        req. setCharacterEncoding("UTF-8");

        System.out.println("获取请求参数name：" + req.getParameter("username"));
        System.out.println("获取请求参数password：" + req.getParameter("password"));
        String[] hobbies = req.getParameterValues("hobby");
        System.out.println("获取请求参数hobby：" + Arrays.asList(hobbies));
    }