backend/restservice/src/main/java/com/plannaplan/security/CasValidator.java

package com.plannaplan.security;

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

    public String validate() throws Exception, CasValidationExcepiton{
        HttpGet request = new HttpGet(CasValidator.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;

        }

    }
}