Can not fetch json data from the spring-boot response - reactjs

Question

I create some spring + react.js application and one of the main function of that is show news from the MySQL database. But when I try to fetch JSON using react function that returns me nothing.
I added 'Content-Type': 'application/json', 'Accept': 'application/json' to the fetch React function, but that not help.
React component:
class News extends Component {
constructor(props) {
super(props);
this.state = {
news: []
}
};
ourFunction = () =>{
const response = fetch('/news/all',{
headers: {
'Content-Type': 'application/json',
'Accept': 'application/json'
}
});
console.log(response);
const body = response.json;
console.log(body);
this.setState({news : body });
console.log(this.state.news);
};
render() {
return (
<div className="news">
<span onClick={this.ourFunction}>Click{}</span>
<div className="news_bar"> Новини</div>
{defaultNewsData.map(({title, content, date}) => <AccordionContainer
title={title}
content={content}
date={date}
/>)}
</div>
);
}
}
export default News;
Spring controller:
#RestController
#RequestMapping(path = "/news")
public class NewsController {
#Autowired
private NewsRepository newsRepository;
#GetMapping("/add")
public String addNewNews(#RequestParam String title, #RequestParam String content){
News news = new News();
news.setTitle(title);
news.setContent(content);
newsRepository.save(news);
return "News Saved";
}
#GetMapping(path = "/all")
public Iterable<News> getAllNews(){
return newsRepository.findAll();
}
}
Expected: to fetch JSON object to the javascript and parse it to the HTML.
Actual: I receive nothing, that is shown on the console.