RestMessage.java

package edu.asu.spring.quadriga.service.impl;

import java.io.StringWriter;

import javax.servlet.http.HttpServletRequest;

import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.VelocityEngine;
import org.apache.velocity.exception.ResourceNotFoundException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.servlet.support.ServletUriComponentsBuilder;

import edu.asu.spring.quadriga.domain.factories.IRestVelocityFactory;
import edu.asu.spring.quadriga.exceptions.RestException;
import edu.asu.spring.quadriga.service.IRestMessage;

@Service
public class RestMessage implements IRestMessage {

    @Autowired
    private IRestVelocityFactory restVelocityFactory;

    /*
     * (non-Javadoc)
     * 
     * @see
     * edu.asu.spring.quadriga.service.impl.IErrorMessageRest#getErrorMsg(java.
     * lang.String, javax.servlet.http.HttpServletRequest)
     */
    @Override
    public String getErrorMsg(String errorMsg) throws RestException {
        StringWriter sw = new StringWriter();
        try {
            VelocityEngine engine = restVelocityFactory.getVelocityRestEngine();
            engine.init();
            Template template = engine.getTemplate("velocitytemplates/error.vm");
            VelocityContext context = new VelocityContext();
            context.put("errMsg", errorMsg);
            template.merge(context, sw);
            return sw.toString();
        } catch (ResourceNotFoundException e) {
            throw new RestException(404, e);
        } catch (Exception e) {
            throw new RestException(400, e);
        }
    }

    @Override
    public String getErrorMsg(String errorMsg, HttpServletRequest req) throws RestException {
        StringWriter sw = new StringWriter();

        try {
            VelocityEngine engine = restVelocityFactory.getVelocityEngine();
            engine.init();
            Template template = engine.getTemplate("velocitytemplates/error.vm");
            VelocityContext context = new VelocityContext();
            context.put("url", ServletUriComponentsBuilder.fromContextPath(req).toUriString());
            context.put("errMsg", errorMsg);
            template.merge(context, sw);
            return sw.toString();
        } catch (ResourceNotFoundException e) {
            throw new RestException(404, e);
        } catch (Exception e) {
            throw new RestException(400, e);
        }
    }

    @Override
    public String getSuccessMsg(String successMessage, HttpServletRequest req) throws RestException {
        StringWriter sw = new StringWriter();

        try {
            VelocityEngine engine = restVelocityFactory.getVelocityEngine();
            engine.init();
            Template template = engine.getTemplate("velocitytemplates/success.vm");
            VelocityContext context = new VelocityContext();
            context.put("url", ServletUriComponentsBuilder.fromContextPath(req).toUriString());
            context.put("successMsg", successMessage);
            template.merge(context, sw);
            return sw.toString();
        } catch (ResourceNotFoundException e) {
            throw new RestException(404, e);
        } catch (Exception e) {
            throw new RestException(400, e);
        }
    }
}