backend/restservice/src/main/java/com/plannaplan/security/cas/DefaultUAMCasValidator.java

package com.plannaplan.security.cas;

import java.net.URLEncoder;

import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class DefaultUAMCasValidator implements CasValidator {
    private static String CAS_URL = "https://cas.amu.edu.pl/cas";
    private final CloseableHttpClient httpClient = HttpClients.createDefault();
    private String service;
    private String ticket;

    public DefaultUAMCasValidator(String service, String ticket) {
        this.service = service;
        this.ticket = ticket;
    }

    @Override
    public String validate() {
        try {
            HttpGet request = new HttpGet(DefaultUAMCasValidator.CAS_URL + "/validate?service="
                    + URLEncoder.encode(this.service, "UTF-8") + "&ticket=" + URLEncoder.encode(this.ticket, "UTF-8"));
            try (CloseableHttpResponse response = httpClient.execute(request)) {

                HttpEntity entity = response.getEntity();

                String result = null;
                if (entity != null) {
                    // return it as a String
                    result = EntityUtils.toString(entity);
                    if (result.replace("\n", "").trim().equals("no")) {
                        throw new CasValidationExcepiton("Validation failed");
                    }
                }

                String res = result.substring(result.indexOf('\n') + 1);
                return res;

            }
        }

        catch (Exception e) {
            throw new CasValidationExcepiton("Cas Validation has failed."); 
        }
    }
}