CODEWITHSUNDEEP
javaservletsjerseyjax-rs
Brian DiCasa
Brian DiCasa

Reputation: 9487

Retrieve Request Body in Exception Mapper

I'm trying to retrieve the body of a request in a JAX-RS ExceptionMapper. Here is my code so far:

@Provider @Componenet
public class BaseExceptionMapper implements ExceptionMapper<Exception> {

    @Context private HttpServletRequest request;

    @Override
    public Response toResponse(Exception ex) {

        // Trying to retrieve request body for logging throws an error
        String requestBody = IOUtils.toString(request.getInputStream());

    }

}

So my dilemma is I can't get the request body for logging because the servlet API wont allow you to call request.getInputStream() / request.getReader() more than once for a request (and JAX-RS Is obviously calling it to parse the request). Does anyone know if there is a way to do what I'm trying to do?

Upvotes: 15

Views: 10928

Answers (3)

dave008
dave008

Reputation: 442

I know this is an old question but I found a workaround that I think it's nice to share.

With the following code you should be able to get the ContainerRequestContext inside the ExceptionMapper, then you can read the body, query params, headers, etc.

@Provider
public class CustomExceptionMapper implements ExceptionMapper<CustomException> {

    @Context
    private ResourceContext resourceContext;

    @Override
    public Response toResponse(CustomException e) {
        ContainerRequestContext requestContext =
                resourceContext.getResource(ContainerRequestContext.class);
    }

}

Hope it can help

Upvotes: 0

ngreen
ngreen

Reputation: 1769

One possible solution is to use a servlet filter and wrap the request, which allows you to intercept read calls to the request input stream. Example pseudo-code (depends on commons-io):

import org.apache.commons.io.output.StringBuilderWriter;
import org.apache.commons.io.input.TeeInputStream;
class MyHttpRequest extends HttpServletRequestWrapper {
    private StringBuilderWriter myString = new StringBuilderWriter();
    private InputStream myIn;
    public MyHttpRequest(HttpServletRequest request) {
        super(request);
        myIn = new TeeInputStream(request.getInputStream(), myString);
    }
    @Override public ServletInputStream getInputStream()
            throws java.io.IOException {
        // this will need an extra wrapper to compile
        return myIn;
    }
    public String getRequestBody() {
        return myString.toString();
    }
}

Filter:

public void doFilter(ServletRequest request, ServletResponse response,
        FilterChain chain) throws IOException, ServletException {
    MyHttpRequest wrapper = new MyHttpRequest((HttpServletRequest) request);
    chain.doFilter(wrapper, response, chain);
}

Mapper:

@Context private HttpServletRequest request;
@Override public Response toResponse(Exception ex) {
    String body = "";
    if (this.request instanceof MyHttpRequest) {
        body = ((MyHttpRequest)request).getRequestBody()
    }
}

You'll need a wrapper class for ServletInputStream, and you can find an example implementation here: Modify HttpServletRequest body

Upvotes: 0

friedeas
friedeas

Reputation: 131

This question is a bit older, but still the answer may help others. My Example also depends on Commons-Io.

You can create a ContainerRequestFilter and use TeeInputStream to proxy/copy the original InputStream:

@Provider
@Priority(Priorities.ENTITY_CODER)
public class CustomRequestWrapperFilter implements ContainerRequestFilter { 

    @Override
    public void filter(ContainerRequestContext requestContext)
            throws IOException {
        ByteArrayOutputStream proxyOutputStream = new ByteArrayOutputStream();
        requestContext.setEntityStream(new TeeInputStream(requestContext.getEntityStream(), proxyOutputStream));
        requestContext.setProperty("ENTITY_STREAM_COPY", proxyOutputStream);
    }

}

And use @Inject with javax.inject.Provider in your ExceptionMapper to get the ContainerRequest injected.

The ExceptionMapper would look like this:

@Provider
public class BaseExceptionMapper implements ExceptionMapper<Exception> {

    @Inject
    private javax.inject.Provider<ContainerRequest> containerRequestProvider;

    @Override
    public Response toResponse(Exception exception) {
        ByteArrayOutputStream bos = (ByteArrayOutputStream) containerRequestProvider
                .get().getProperty("ENTITY_STREAM_COPY");
        String requestBody = bos.toString();
        ...
    }

}

When I have also used the @Component annotation my ExceptionMapper was not used. I think that @Provider is sufficient.

Upvotes: 12

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