目的：将返回 的body中的数据进行url编码后 再进行返回

ResponseBodyFilter

@WebFilter(filterName = "responseBodyFilter",
        urlPatterns = {
                "/order/orderCancel"
        })
public class ResponseBodyFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        HttpServletResponse resp = (HttpServletResponse) servletResponse;
        MyResponseWrapper mResp = new MyResponseWrapper(resp);
        //使用复写后的wrapper
        filterChain.doFilter(servletRequest, mResp);
        // 获取缓存的响应数据
        byte[] bytes = mResp.getBytes();
        String backMsg = new String(bytes, "UTF-8");
        String encode = URLEncoder.encode(backMsg, "UTF-8");
        byte[] bts = encode.getBytes();
        // 将编码数据响应给客户端
        resp.getOutputStream().write(bts);
    }

    @Override
    public void destroy() {

    }
}

MyResponseWrapper

public class MyResponseWrapper extends HttpServletResponseWrapper {
    private static final Logger logger = LoggerFactory.getLogger(MyResponseWrapper.class);
    private ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    private HttpServletResponse response;
    private PrintWriter pwrite;

    public MyResponseWrapper(HttpServletResponse response) {
        super(response);
        this.response = response;
    }

    /**
     * // 将数据写到 byte 中
     *
     * @return
     * @throws IOException
     */
    @Override
    public ServletOutputStream getOutputStream() throws IOException {
        return new MyServletOutputStream(bytes);
    }

    /**
     * 重写父类的 getWriter() 方法，将响应数据缓存在 PrintWriter 中
     */
    @Override
    public PrintWriter getWriter() throws IOException {
        try {
            pwrite = new PrintWriter(new OutputStreamWriter(bytes, "utf-8"));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return pwrite;
    }

    /**
     * 获取缓存在 PrintWriter 中的响应数据
     *
     * @return
     */
    public byte[] getBytes() {
        if (null != pwrite) {
            pwrite.close();
            return bytes.toByteArray();
        }

        if (null != bytes) {
            try {
                bytes.flush();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return bytes.toByteArray();
    }

}