[FIXED] Reporting Errors In Spring Boot Startup

Issue

When my application.yml does not match the database schema properly in my springboot application it will fail to start with a very verbose exception trace.

This trace is very difficult for a user to parse, even if I log the failure reason, it will be lost in a barrage of logs.

Worse yet, if the user launcher the program from a shortcut it will disappear and they will need to dig up the log or run it from the command line.

I would like to popup a message box right when I encounter the problem.

I tried adding a JOptionPane.showMessageDialog but this throws a java.awt.HeadlessException.

Is there a more canonical way to provide user feedback when a spring boot application fails to start?

Solution

Spring Boot app is headless by default - it means there is no GUI supposed. JOptionPane.showMessageDialog - is part of GUI Java Swing framework.

So to use this GUI feature, you need to make you Spring Boot not headless.

Example (short version of code from here):

@SpringBootApplication
public class DemoSbSwingApplication extends JFrame {
    public static void main(String[] args) {
        var ctx = new SpringApplicationBuilder(DemoSbSwingApplication.class)
                .headless(false)
                .run(args);
        EventQueue.invokeLater(() -> {
            var ex = ctx.getBean(DemoSbSwingApplication.class);
            ex.setVisible(true);
        });
    }

    public DemoSbSwingApplication() {
        var pane = getContentPane();

        JOptionPane.showMessageDialog(pane, "TEST TEST TEST");
    }

}

Answered By - artild
Answer Checked By - Dawn Plyler (JavaFixing Volunteer)