RESTfulErrorHandler.java

package com.github.restifyerrors;



import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.node.ObjectNode;

import play.Logger;
import play.Logger.ALogger;
import play.mvc.Action;
import play.mvc.Http.Context;
import play.mvc.Result;

import com.github.restifyerrors.exceptions.HTTPErrorType;
import com.github.restifyerrors.exceptions.HTTPException;

/***
 * 
 * RestfulErrorHandler converts any exception thrown from Service/API layer to proper HTTP Error.
 *  
 * This will be annotated on Controller methods.
 * 
 * @author Rutvijkumar Shah
 *
 */
public class RESTfulErrorHandler extends Action.Simple {
	
	private static ALogger logger=Logger.of(RESTfulErrorHandler.class);

	
	/****
	 * Convert HTTP Error to Play.mvc.Result
	 * 
	 * @param type
	 * @param json
	 * @return
	 */
	private Result resultFromHttpErrorType(HTTPErrorType type,JsonNode json){
		Result result=null;
		if(type ==null ){
			result=internalServerError(json);
		}
		else if(type.equals(HTTPErrorType.BAD_REQUEST)){
			result=badRequest(json);
		}else if (type.equals(HTTPErrorType.FORBIDDEN_REQUEST)){
			result=forbidden(json);
		}else if (type.equals(HTTPErrorType.NOT_FOUND_REQUEST)){
			result=notFound(json);
		}else if (type.equals(HTTPErrorType.UN_AUTHORIZED_REQUEST)){
			result=unauthorized(json);
		}else{
			result=internalServerError(json);
		}
		return result;
	}
	
	
	@SuppressWarnings("unchecked")
	@Override
	public Result call(Context context) {
		Result result=null;
		try{
			
			//Intercepts the call and delegate to controller
			result= delegate.call(context);
		}catch (HTTPException e) {
			logger.error("HTTPException:"+e.getMessage(),e);
			//Mapping API Exception to HTTP Errors 
			JsonNode json = e.getJSON();
			result=this.resultFromHttpErrorType(e.getHttpErrorType(), json);
		}catch (Throwable e) {
			logger.error("Exception:"+e.getMessage(),e);
			result= internalServerError("Internal Error");//Default result
			//checking registry to get exception mapping
			ExceptionInfo exInfo=RestifyErrorsRegistry.getExceptionInfo(e);
			
			if(exInfo !=null){
				
				if(exInfo.getErrorType() !=null){
					ObjectNode jsonObj = play.libs.Json.newObject();
					jsonObj.put("error",exInfo.getErrorType().toString());
					result=this.resultFromHttpErrorType(exInfo.getErrorType(), jsonObj);
				}
				if(exInfo.getResultBuilder() !=null){
					result=exInfo.getResultBuilder().getResult(e);
				}
				
			}
		}
		return result;
	}
}