Serializing BindingResult Errors to JSON

someClasses.java

package model;

import java.util.List;
import java.util.Map;

import org.codehaus.jackson.annotate.JsonAutoDetect;
import org.codehaus.jackson.annotate.JsonAutoDetect.Visibility;
import org.codehaus.jackson.annotate.JsonProperty;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;

import com.google.common.collect.Lists;
import com.google.common.collect.Maps;

@JsonAutoDetect(fieldVisibility=Visibility.NONE, getterVisibility=Visibility.NONE, isGetterVisibility=Visibility.NONE)
public class ValidationException extends Exception{

	private static final long serialVersionUID = 1L;

	@JsonProperty
	private boolean success = false;
	
	@JsonProperty
	private List<String> errors = Lists.newArrayList();
	
	@JsonProperty
	private Map<String,String> fieldErrors = Maps.newHashMap();
	
	
	public ValidationException(){}
	
	public ValidationException(BindingResult bindingResult){
		for(FieldError error : bindingResult.getFieldErrors()){
			fieldErrors.put(error.getField(), error.getDefaultMessage());
		}
	}
	
	public boolean getSuccess(){
		return success;
	}
	
	public List<String> getErrors(){
		return errors;
	}
	
	public Map<String, String> getFieldErrors(){
		return fieldErrors;
	}
}


/*
 *  The following two classes are from https://github.com/rstoyanchev/spring-mvc-31-demo/tree/master/src/main/java/org/springframework/samples/mvc31/exceptionhandler
 */


package web.exceptions;

import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;

public class GlobalExceptionHandler {
	/**
	 * This method basically just serializes the exception to JSON
	 */
	@ExceptionHandler(value=ValidationException.class)
	public @ResponseBody ValidationException handle(ValidationException exception) {
		return exception;
	}
}

package web.exceptions;

import java.lang.reflect.Method;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.method.annotation.ExceptionHandlerMethodResolver;
import org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver;
import org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod;

/**
 * Extends {@link ExceptionHandlerExceptionResolver} to provide "global"
 * {@code @ExceptionHandler} methods for use across all controllers.
 * 
 * <p>
 * Plugged in via
 * {@link WebConfig#configureHandlerExceptionResolvers(java.util.List)}.
 */
public class ExtendedExceptionHandlerExceptionResolver extends
		ExceptionHandlerExceptionResolver {

	private Object handler;

	private ExceptionHandlerMethodResolver methodResolver;

	/**
	 * Provide a handler with @{@link ExceptionHandler} methods.
	 */
	public void setExceptionHandler(Object handler) {
		this.handler = handler;
		this.methodResolver = new ExceptionHandlerMethodResolver(
				handler.getClass());
	}

	@Override
	protected ServletInvocableHandlerMethod getExceptionHandlerMethod(
			HandlerMethod handlerMethod, Exception exception) {
		ServletInvocableHandlerMethod result = super.getExceptionHandlerMethod(
				handlerMethod, exception);
		if (result != null) {
			return result;
		}
		Method method = this.methodResolver.resolveMethod(exception);
		return (method != null) ? new ServletInvocableHandlerMethod(
				this.handler, method) : null;
	}

}