JavaWeb--POST/GET请求参数乱码问题

 //1、解决POST乱码问题
        request.setCharacterEncoding("UTF-8");


        //2、获取username
        String username = request.getParameter("username");
        System.out.println(username);

 String username = request.getParameter("username");
        //System.out.println(username);
        System.out.println("解决乱码问题前"+username);
        //3、GET，获取参数的方式：getQueryString
        //乱码原因：tomcat对url解码时使用的是默认字符集ISO-8859-1
        //3.1 先对乱码数据进行编码：转为字节数组
        byte[] bytes = username.getBytes(StandardCharsets.ISO_8859_1);
        //3.2字节数组解码
        username = new String(bytes,StandardCharsets.UTF_8);
        System.out.println("解决乱码问题后"+username);