Olá 
Criei um programa que recebe um input html e a partir do javascript é chamada uma classe java que retorna uma string com o resultado. no entanto está a dar um erro que nao consigo resolver! Deixo aqui o ficheiro Javascript e o Service e Controller java. Se precisarem de mais alguma coisa é só dizer 
JavaScript:
function myFunction(noticia) {
var noticia = document.getElementById('txtCC1').value;
$.ajax({
type: 'GET',
url: '/demo-checker/src/main/java/com/newschecker/demochecker/controller/NewsController',
success: function(noticia) {
var five = pesquisaFakeNews("teste teste teste");
//DO SOMETHING HERE AFTER YOU GET THE RESPONSE FROM the validate function
document.getElementById("res").innerHTML = five;
},
error: function(jqXHR, textStatus, errorThrown) {
document.getElementById("res").innerHTML = "Erro";
}
});
}
Service Java
package com.newschecker.demochecker.service;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;
import javafx.util.Pair;
@Service
public class NewsCheckerService {
private static Logger log = LoggerFactory.getLogger(NewsCheckerService.class);
public String pesquisaFakeNews(String noticia) throws IOException {
noticia = isolaPalavrasChave(noticia);
...
Controller
package com.newschecker.demochecker.controller;
import java.io.IOException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import com.newschecker.demochecker.service.NewsCheckerService;
@Controller
public class NewsController {
@Autowired
private NewsCheckerService service;
@RequestMapping("/demo-checker/src/main/java/com/newschecker/demochecker/controller/NewsController")
public String getDadosViaUrl(String data) throws IOException {
String resposta = service.pesquisaFakeNews(data);
return resposta;
}
}
Pagina Erro LocalHost:
Console
Obrigado
