springboot 拦截 response 过滤内容

https://blog.csdn.net/a582127421/article/details/78321888#commentBox

@Component
@Order(1)
@Slf4j
@WebFilter(filterName = "errorMsgFilter", urlPatterns = "/*")
public class ErrorMsgFilter implements Filter {

@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
    HttpServletResponse response = (HttpServletResponse) servletResponse;
    ErrorMsgFilterResponseWrapper wrapper = new ErrorMsgFilterResponseWrapper(response);

    filterChain.doFilter(servletRequest, wrapper);
    String result = wrapper.getResponseData(response.getCharacterEncoding());
    //...gono
}

class ErrorMsgFilterResponseWrapper extends HttpServletResponseWrapper {
    private ByteArrayOutputStream buffer = null;
    private ServletOutputStream out = null;
    private PrintWriter writer = null;

    public ErrorMsgFilterResponseWrapper(HttpServletResponse response) throws IOException{
        super(response);
        buffer = new ByteArrayOutputStream();
        out = new WapperedOutputStream(buffer);
        writer = new PrintWriter(new OutputStreamWriter(buffer, "UTF-8"));
    }

    @Override
    public ServletOutputStream getOutputStream() throws IOException {
        return out;
    }

    @Override
    public PrintWriter getWriter() throws IOException {
        return writer;
    }

    @Override
    public void flushBuffer() throws IOException {
        if (out != null) {
            out.flush();
        }
        if (writer != null) {
            writer.flush();
        }
    }

    @Override
    public void reset() {
        buffer.reset();
    }

    public String getResponseData(String charset) throws IOException {
        flushBuffer();
        byte[] bytes = buffer.toByteArray();
        try {
            return new String(bytes, charset);
        } catch (UnsupportedEncodingException e) {
            return "";
        }
    }

    class WapperedOutputStream extends ServletOutputStream {
        private ByteArrayOutputStream bos = null;
        public WapperedOutputStream(ByteArrayOutputStream stream) throws IOException {
            bos = stream;
        }
        @Override
        public void write(int b) throws IOException {
            bos.write(b);
        }

        @Override
        public boolean isReady() {
            return false;
        }

        @Override
        public void setWriteListener(WriteListener listener) {

        }
    }
}