DebugExceptionMapper.java

import org.apache.commons.lang.exception.ExceptionUtils;

import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.ws.rs.ext.ExceptionMapper;
import javax.ws.rs.ext.Provider;
import java.util.StringJoiner;

/**
 * Catch-all exception mapper that creates response with message and stack trace.
 */
@Provider
public class DebugExceptionMapper implements ExceptionMapper<Exception> {
  @Override
  public Response toResponse(Exception e) {
    final StringJoiner body = new StringJoiner("\n\n");
    body.add("==== Uncaught Exception ====");
    body.add("Message: " + e.getMessage());
    body.add("Stack: \n" + ExceptionUtils.getStackTrace(e));
    return Response.status(500)
        .entity(body.toString())
        .type(MediaType.TEXT_PLAIN_TYPE)
        .build();
  }
}