Re: MongoDB can't serialize class when saving on database

[Jeff Yemin]

If you want to be able to serialize and deserialize POJOs like News and TwitterModel, you need to use an Object Document Mapper (ODM), like Morphia or Spring Data MongoDB.  Otherwise, you must write your own code to handle the mapping to and from your object mode and instances of BasicDBObject.

Regards,
Jeff

On Monday, October 8, 2012 10:30:51 PM UTC-4, Gustavo Coelho wrote:

[code]

package br.com.ucsal.monografia.controller;

import java.util.List;

import br.com.ucsal.monografia.model.HashTag;

import br.com.ucsal.monografia.model.News;

import br.com.ucsal.monografia.service.HashTagService;

import br.com.ucsal.monografia.service.NewsService;

import br.com.ucsal.monografia.twitter.TwitterLoader;

public class CargaNews {

private static void save(List<News> newss) {

NewsService newsService = new NewsService();

for (News news : newss) {

newsService.save(news);

}

}

}

[/code]

[code]

package br.com.ucsal.monografia.service;

import java.util.List;

import java.util.Map;

import br.com.caelum.vraptor.ioc.Component;

import br.com.ucsal.monografia.dao.NewsDao;

import br.com.ucsal.monografia.model.News;

@Component

public class NewsService {

private NewsDao dao = new NewsDao();

public void save(News news) {

dao.save(news);

}

}

[/code]

[code]

package br.com.ucsal.monografia.dao;

import java.util.ArrayList;

import java.util.List;

import java.util.Map;

import br.com.ucsal.monografia.converter.NewsConverter;

import br.com.ucsal.monografia.model.News;

import com.mongodb.DBObject;

public class NewsDao extends EntityDao<News> {

public NewsDao() {

super(News.class);

}

public void save(News news) {

Map<String, Object> mapNews = new NewsConverter().converterToMap(news);

save(mapNews);

}

}

[/code]

[code]

package br.com.ucsal.monografia.converter;

import java.util.HashMap;

import java.util.Map;

import br.com.ucsal.monografia.model.Feed;

import br.com.ucsal.monografia.model.News;

import br.com.ucsal.monografia.model.NewsType;

import br.com.ucsal.monografia.model.TwitterModel;

import com.mongodb.DBObject;

public class NewsConverter {

public Map<String, Object> converterToMap(News news) {

Map<String, Object> mapNews = new HashMap<String, Object>();

mapNews.put("twitterModel", news.getTwitterModel());

mapNews.put("feed", news.getFeed());

mapNews.put("newsType", news.getNewsType());

return mapNews;

}

}

[/code]

[code]

package br.com.ucsal.monografia.model;

import java.io.Serializable;

public class TwitterModel implements Serializable{

private static final long serialVersionUID = 7686683331955611044L;

private String twitt;

public TwitterModel() {

}

public String getTwitt() {

return twitt;

}

public void setTwitt(String twitt) {

this.twitt = twitt;

}

} 

[/code]

[code]

package br.com.ucsal.monografia.model;

import java.io.Serializable;

public class News implements Serializable{

private static final long serialVersionUID = 7686683331955611044L;

    private String id;

private TwitterModel twitterModel;

private Feed feed;

private NewsType newsType;

public News(TwitterModel twitterModel, Feed feed, NewsType newsType) {

this.twitterModel = twitterModel;

this.feed = feed;

this.newsType = newsType;

}

public News() {

}

public String getId() {

return id;

}

public void setId(String id) {

this.id = id;

}

public TwitterModel getTwitterModel() {

return twitterModel;

}

public TwitterModel getTwitter() {

return twitterModel;

}

public void setTwitterModel(TwitterModel twitterModel) {

this.twitterModel = twitterModel;

}

public Feed getFeed() {

return feed;

}

public void setFeed(Feed feed) {

this.feed = feed;

}

public NewsType getNewsType() {

return newsType;

}

public void setNewsType(NewsType newsType) {

this.newsType = newsType;

}

} 

[/code]

[code]

Exception in thread "main" java.lang.IllegalArgumentException: can't serialize class br.com.ucsal.monografia.model.TwitterModel

at org.bson.BSONEncoder._putObjectField(BSONEncoder.java:188)

at org.bson.BSONEncoder.putObject(BSONEncoder.java:119)

at org.bson.BSONEncoder.putObject(BSONEncoder.java:65)

at com.mongodb.DBApiLayer$MyCollection.insert(DBApiLayer.java:131)

at com.mongodb.DBApiLayer$MyCollection.insert(DBApiLayer.java:97)

at com.mongodb.DBCollection.insert(DBCollection.java:75)

at com.mongodb.DBCollection.save(DBCollection.java:545)

at com.mongodb.DBCollection.save(DBCollection.java:523)

at br.com.ucsal.monografia.dao.EntityDao.save(EntityDao.java:39)

at br.com.ucsal.monografia.dao.NewsDao.save(NewsDao.java:20)

at br.com.ucsal.monografia.service.NewsService.save(NewsService.java:16)

at br.com.ucsal.monografia.controller.CargaNews.save(CargaNews.java:32)

at br.com.ucsal.monografia.controller.CargaNews.main(CargaNews.java:23)

[/code]

[Gustavo Coelho]

Thanks very much, that gives me a north to look at.