Freemarker Debugger framework usage example - debugging

Question

I have started working on a Freemarker Debugger using breakpoints etc. The supplied framework is based on java RMI. So far I get it to suspend at one breakpoint but then ... nothing.
Is there a very basic example setup for the serverpart and the client part other then the debug/imp classes supplied with the sources. That would be of great help.
this is my server class:
class DebuggerServer {
private final int port;
private final String templateName1;
private final Environment templateEnv;
private boolean stop = false;
public DebuggerServer(String templateName) throws IOException {
System.setProperty("freemarker.debug.password", "hello");
port = SecurityUtilities.getSystemProperty("freemarker.debug.port", Debugger.DEFAULT_PORT).intValue();
System.setProperty("freemarker.debug.password", "hello");
Configuration cfg = new Configuration();
// Some other recommended settings:
cfg.setIncompatibleImprovements(new Version(2, 3, 20));
cfg.setDefaultEncoding("UTF-8");
cfg.setLocale(Locale.US);
cfg.setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER);
Template template = cfg.getTemplate(templateName);
templateName1 = template.getName();
System.out.println("Debugging " + templateName1);
Map<String, Object> root = new HashMap();
Writer consoleWriter = new OutputStreamWriter(System.out);
templateEnv = new Environment(template, null, consoleWriter);
DebuggerService.registerTemplate(template);
}
public void start() {
new Thread(new Runnable() {
#Override
public void run() {
startInternal();
}
}, "FreeMarker Debugger Server Acceptor").start();
}
private void startInternal() {
boolean handled = false;
while (!stop) {
List breakPoints = DebuggerService.getBreakpoints(templateName1);
for (int i = 0; i < breakPoints.size(); i++) {
try {
Breakpoint bp = (Breakpoint) breakPoints.get(i);
handled = DebuggerService.suspendEnvironment(templateEnv, templateName1, bp.getLine());
} catch (RemoteException e) {
System.err.println(e.getMessage());
}
}
}
}
public void stop() {
this.stop = true;
}
}
This is the client class:
class DebuggerClientHandler {
private final Debugger client;
private boolean stop = false;
public DebuggerClientHandler(String templateName) throws IOException {
// System.setProperty("freemarker.debug.password", "hello");
// System.setProperty("java.rmi.server.hostname", "192.168.2.160");
client = DebuggerClient.getDebugger(InetAddress.getByName("localhost"), Debugger.DEFAULT_PORT, "hello");
client.addDebuggerListener(environmentSuspendedEvent -> {
System.out.println("Break " + environmentSuspendedEvent.getName() + " at line " + environmentSuspendedEvent.getLine());
// environmentSuspendedEvent.getEnvironment().resume();
});
}
public void start() {
new Thread(new Runnable() {
#Override
public void run() {
startInternal();
}
}, "FreeMarker Debugger Server").start();
}
private void startInternal() {
while (!stop) {
}
}
public void stop() {
this.stop = true;
}
public void addBreakPoint(String s, int i) throws RemoteException {
Breakpoint bp = new Breakpoint(s, i);
List breakpoints = client.getBreakpoints();
client.addBreakpoint(bp);
}
}

Answer 1

Liferay IDE (https://github.com/liferay/liferay-ide) has FreeMarker template debug support (https://issues.liferay.com/browse/IDE-976), so somehow they managed to use it. I have never seen it in action though. Other than that, I'm not aware of anything that uses the debug API.