如何将错误消息添加到响应正文？

Question

I have a Java Servlet class where I try to set the error status when there is an authentication issue in my application. However, the issue is, I am able to set the error status but am not able to set an error message in the body of the response. Below is my attempt:

AuthorizationFilter.java

public class AuthorizationFilter implements Filter {
    @Autowired
    private ExceptionHandler exceptionHandler;

    @Override
    public void doFilter(final ServletRequest servletRequest, final ServletResponse servletResponse, final FilterChain filterChain) throws IOException, ServletException {
        final HttpServletRequest request = (HttpServletRequest) servletRequest;
        final HttpServletResponse response = (HttpServletResponse) servletResponse;

        UserSession userSession = null;
        try {
             userSession = authProvider.authenticate(request, response);
        } catch(RestUsageException throwable) {
            exceptionHandler.handle(throwable.getExceptionCode(), throwable.getMessage(), throwable, response);
            response.sendError(throwable.getRespondStatus().value());
        //  response.sendError(throwable.getRespondStatus().value(), "Message");
            return;
        }
    ...more code here
    }

ExceptionHandler.java

@Override
public void handle(String exceptionCode, String message, Throwable throwable, final ServletResponse response) throws IOException {

    String uuid = UUID.randomUUID().toString();
    ObjectWriter ow = new ObjectMapper().writer().withDefaultPrettyPrinter();
    String json = "{  \n" +
                "   \"errorCode\":\""+exceptionCode+"\",\n" +
                "   \"errorMessage\":\""+throwable.getMessage()+"\",\n" +
                "   \"success\":\"false\",\n" +
                "   \"errorId\":\""+uuid+"\"\n" +
                "}";
    response.getOutputStream().println(json);
  //  response.getOutputStream().flush();
}

My throwable contains the correct HTTP status that I want to display. I tried two things:

1. I tried to do follow this method: public void sendError(int sc, java.lang.String msg) throws java.io.IOException

But the message seems to only be displayed in the HTTP Status header.

2. I tried to response.getOutputStream().flush(); to flush out the response but then when I try to perform response.sendError(throwable.getRespondStatus().value()); afterwards, I get an error saying my Response is already committed , and my body shows up but the status ends up being 200.

Any ideas on how to set the error message body? Any help would be appreciated. Thanks!

Answer 1

You cant use the respons streams in combination with response.sendError(...) . Try to use respons.setStatus(...) instead.