I build a Java Swing application in Java 8. So I try to use a contact a RestWebService in https, this is the code:

public boolean sincronizzaArticoli(List<Articoli> lista){
        try {
            Propr p = new Propr();
            Properties properties= p.getProps();
            //
            ArticoliWebBody body = new ArticoliWebBody();
            body.setSuffisso(properties.getProperty("prefissoTabella"));
            body.setArticoli(lista);
            //
            URL url;
            URLConnection urlConnection;
            DataOutputStream outStream;
            DataInputStream inStream;
            String uriString = properties.getProperty("sitoRemoto");
            
            
            
            uriString = uriString.substring(0, uriString.lastIndexOf('/'))+"/WebApi.php/saveArticoli";
            url = new URL(uriString);
            urlConnection = url.openConnection();
            urlConnection.setDoInput(true);
            urlConnection.setDoOutput(true);
            urlConnection.setUseCaches(false);
            urlConnection.setRequestProperty("Content-Type", "application/json");
            urlConnection.setRequestProperty("Accept", "application/json");
            ((HttpURLConnection) urlConnection).setRequestMethod("POST");
            Gson gson = new Gson(); 
            String jsonString = gson.toJson(body);  
            //System.out.println(jsonString);
            // Create I/O streams
            try(OutputStream os = urlConnection.getOutputStream()) {
                byte[] input = jsonString.getBytes("utf-8");
                os.write(input, 0, input.length);           
            }
            inStream = new DataInputStream(urlConnection.getInputStream());
            // Send request
            // Get Response
            // - For debugging purposes only!
            String buffer;
            while((buffer = inStream.readLine()) != null) {
                 // Close I/O streams
                inStream.close();
                if(buffer.contains("ok"))
                    return true;
                else{
                    log.information("errore: " );
                    log.information(buffer);
                }
                return false;
            }
            return false;
        }
        catch(Exception ex) {
            System.out.println("Exception cought:n"+ ex.toString());
            log.logStackTrace(ex);
        }
        return false;
    }

If I try to run this code, I received the following error:

javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
DEBUG [pool-2-thread-1] (MyLog4J.java:42) - javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.ssl.Alerts.getSSLException(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
    at sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
    at sun.security.ssl.Handshaker.processLoop(Unknown Source)
    at sun.security.ssl.Handshaker.process_record(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(Unknown Source)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getOutputStream(Unknown Source)
    at prove.HTTPRequest.sincronizzaArticoli(HTTPRequest.java:58)
    at Backup.PanelChiusuraGiornata$1.doInBackground(PanelChiusuraGiornata.java:473)
    at Backup.PanelChiusuraGiornata$1.doInBackground(PanelChiusuraGiornata.java:1)
    at javax.swing.SwingWorker$1.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at javax.swing.SwingWorker.run(Unknown Source)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.validator.PKIXValidator.doBuild(Unknown Source)
    at sun.security.validator.PKIXValidator.engineValidate(Unknown Source)
    at sun.security.validator.Validator.validate(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
    ... 23 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
    at java.security.cert.CertPathBuilder.build(Unknown Source)
    ... 29 more

How can I do to bypass this error? I should be able to execute this application on different computer