resp.getWriter()向web响应时出现乱码

学习了doGet()，发现通过resp(HttpServletResponse类)调用getWriter()来响应文字至页面时出现乱码，这时我们需要设置上下文的编码格式，有两种方法：
方法一：

resp.setContentType("text/html;");  
resp.setCharacterEncoding("UTF-8");  //使用setCharacterEncoding()来设置其编码格式

方法二：

resp.setContentType("text/html;charset=utf-8");  //直接使用setContentType()方法

需要注意：编码格式需要设置在getWriter之前

官方描述：

This method can be called repeatedly to change the character encoding. This method has no effect if it is called after getWriter has been called or after the response has been committed.