1. 配置自己想要的编码

Paste_Image.png

2. 编写过滤器

public class EncodingFilter implements Filter {
    String encoding;
    
    public EncodingFilter() {
    }

    public void destroy() {
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest hRquest = (HttpServletRequest)request;
        MyHttpRequest myRequest = new MyHttpRequest(hRquest,encoding);
        //过滤链传递时要传递的是我们处理过的request
        chain.doFilter(myRequest, response);
    }

    public void init(FilterConfig fConfig) throws ServletException {
        encoding = fConfig.getInitParameter("encoding");
        System.out.println("读取到的编码："+encoding);
    }

}

//使用装饰者模式重新构建getParameter方法
class MyHttpRequest extends HttpServletRequestWrapper{

    //被装饰的对象
    HttpServletRequest hRequest;
    String encoding;
    
    public MyHttpRequest(HttpServletRequest request,String encoding) {
        super(request);
        hRequest = request;
        this.encoding = encoding;
    }
    
    @Override
    public String getParameter(String name) {
        
        //获取原来的参数
        String value = hRequest.getParameter(name);
        //如果是get方法，那么手动解码
        if ("GET".equals(hRequest.getMethod())){
            try {
                return new String(value.getBytes("iso-8859-1"),encoding);
            } catch (UnsupportedEncodingException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        
        return value;
    }
    
}

3. servlet获取前端输入的参数

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        String name = request.getParameter("name");
        String password = request.getParameter("password");
        System.out.println(name+":"+password);
        /*
         * 注意：
         * 因为我们只是重写了request.getParameter()方法，其他方法无效哦*/
    }