Automate JackSON conversion in ExceptionHandler?

Hi,

I am writing a RESTful web service. All the outputs of the web service is currently in JSON format and I make use of MappingJacksonHttpMessageConverter to convert all my positive output to JSON.

I facing some problems on the error handling part. As I read from internet, @ExceptionHandler only can returns String / MAV. I could not apply the @ResponseBody that I used in other method to auto-convert my output to JSON. My snapshot of code as below (modified from Spring Doc v3.0.0, Section 18.2.6):

Code:

---

@Controller
public class SimpleController {

 // other controller method omitted

 @ExceptionHandler(IOException.class)
 public String handleIOException(IOException ex, HttpServletRequest request) {
    // Convert 'ex.getMessage()' with to ErrorMessage with Object Mapper
    ErrorMessage errorMessage = new ErrorMessage(ex.getMessage());
    String ret = mapper.writeValueAsString(errorMessage);
    ....
    return ret;
 }

---

Code:

---

@XmlRootElement(name="errorMessage")
public class ErrorMessage {
       
        private String error_message;

       
        public ErrorMessage() {}
       
        public ErrorMessage(String error_message) {
                this.error_message = error_message;
        }

        public String getError_message() {
                return error_message;
        }

        public void setError_message(String error_message) {
                this.error_message = error_message;
        }

}

---

The expecting output is (in JSON)
{"error_message":"this is the real exception error message."}

My questions is - is that any idea to automate the process besides doing to conversion in every @ExceptionHandler method?

Thanks for your advises.

Hi,

I found a half-way solution for my case. I added AnnotationMethodHandlerExceptionResolver in the servlet.xml

Code:

---

<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerExceptionResolver">
    <property name="messageConverters">
        <list>
            <ref bean="marshallingConverter" />
            <ref bean="jsonConverter" />
        </list>
    </property>
</bean>

---

And my Controller code like below:

Code:

---

@Controller
public class SimpleController {

    // other controller method omitted

    @ExceptionHandler(IOException.class)
    public @ResponseBody IOException handleIOException(IOException ex, HttpServletRequest request) {
        return ex;
    }
}

---

By doing so, I can get the exception with message in JSON

Code:

---

{"cause":null,"message":"my custom exception message","localizedMessage":"my custom exception message","stackTrace":[{"className":"sun.reflect.NativeMethodAccessorImpl","fileName":null,"lineNumber":-2,"methodName":"invoke0","nativeMethod":true},{"className":"sun.reflect.NativeMethodAccessorImpl","fileName":null,"lineNumber":-1,"methodName":"invoke","nativeMethod":false},
.....
< Long Long Stack Trace>
.....
]

---

Any idea to take out the 'stack trace' from the JSON ? Actually, I only interest to send BOLD text as JSON to the REST client.
I would like to log the stack trace in REST server log, but not sending the stack trace to the rest client (Its meaningless to REST Client)

Thanks for viewing and/or advises. :)