Codename One Util.downloadUrlSafely example

MyApplication.java

import com.codename1.components.SpanLabel;
import com.codename1.components.ToastBar;
import static com.codename1.ui.CN.*;
import com.codename1.ui.Display;
import com.codename1.ui.Form;
import com.codename1.ui.Dialog;
import com.codename1.ui.Label;
import com.codename1.ui.plaf.UIManager;
import com.codename1.ui.util.Resources;
import com.codename1.io.Log;
import com.codename1.ui.Toolbar;
import java.io.IOException;
import com.codename1.ui.layouts.BoxLayout;
import com.codename1.io.NetworkEvent;
import com.codename1.io.Storage;
import com.codename1.io.Util;
import java.util.Timer;
import java.util.TimerTask;

/**
 * This file was generated by <a href="https://www.codenameone.com/">Codename One</a> for the purpose 
 * of building native mobile applications using Java.
 */
public class MyApplication {

    private Form current;
    private Resources theme;

    public void init(Object context) {
        // use two network threads instead of one
        updateNetworkThreadCount(2);

        theme = UIManager.initFirstTheme("/theme");

        // Enable Toolbar on all Forms by default
        Toolbar.setGlobalToolbar(true);

        // Pro only feature
        Log.bindCrashProtection(true);

        // Manage both network errors (connectivity issues) and server errors (codes different from 2xx)
        addNetworkAndServerErrorListener();    
    }
    
    public void start() {
        if(current != null){
            current.show();
            return;
        }
        
        String url = "https://www.informatica-libera.net/video/AVO_Cariati_Pasqua_2020.mp4"; // 38 MB
        
        Form form = new Form("Test Download 38MB", BoxLayout.y());
        Label infoLabel = new Label("Starting download...");
        form.add(infoLabel);
        
        try {
            Util.downloadUrlSafely(url, "myHeavyVideo.mp4", (percentage) -> {
                // percentage callback
                infoLabel.setText("Downloaded: " + percentage + "%");
                infoLabel.repaint();
            }, (filename) -> {
                // file saved callback
                infoLabel.setText("Downloaded completed");
                int fileSizeMB = Storage.getInstance().entrySize(filename) / 1048576;
                form.add("Checking files size: " + fileSizeMB + " MB");
                form.revalidate();
            });
        } catch (IOException ex) {
            Log.p("Error in downloading: " + url);
            Log.e(ex);
            form.add(new SpanLabel("Error in downloading:\n" + url));
            form.revalidate();
        }

        form.show();
        
        
    }

    public void stop() {
        current = getCurrentForm();
        if(current instanceof Dialog) {
            ((Dialog)current).dispose();
            current = getCurrentForm();
        }
    }
    
    public void destroy() {
    }
    
    private void addNetworkAndServerErrorListener() {
        // The following way to manage network errors is discussed here:
        // https://stackoverflow.com/questions/61993127/distinguish-between-server-side-errors-and-connection-problems
        addNetworkErrorListener(err -> {
            // prevents the event from propagating
            err.consume();

            if (err.getError() != null) {
                // this is the case of a network error,
                // like: java.io.IOException: Unreachable
                Log.p("Error connectiong to: " + err.getConnectionRequest().getUrl(), Log.ERROR);
                // maybe there are connectivity issues, let's try again
                ToastBar.showInfoMessage("Reconnect...");
                Timer timer = new Timer();
                timer.schedule(new TimerTask() {
                    @Override
                    public void run() {
                        err.getConnectionRequest().retry();
                    }
                }, 2000);
            } else {
                // this is the case of a server error
                // logs the error
                String errorLog = "REST ERROR\nURL:" + err.getConnectionRequest().getUrl()
                        + "\nMethod: " + err.getConnectionRequest().getHttpMethod()
                        + "\nResponse code: " + err.getConnectionRequest().getResponseCode();
                if (err.getConnectionRequest().getRequestBody() != null) {
                    errorLog += "\nRequest body: " + err.getConnectionRequest().getRequestBody();
                }
                if (err.getConnectionRequest().getResponseData() != null) {
                    errorLog += "\nResponse message: " + new String(err.getConnectionRequest().getResponseData());
                }
                if (err.getConnectionRequest().getResponseErrorMessage() != null) {
                    errorLog += "\nResponse error message: " + err.getConnectionRequest().getResponseErrorMessage();
                }
                Log.p(errorLog, Log.ERROR);

                Log.sendLogAsync();
                ToastBar.showErrorMessage("Server Error", 10000);
            }
        });
    }

}