@Controller
@Request("/hello")
public class HelloWorldController {
    
    @Request("world")
    public String helloWorld() {
        System.out.println("Well done! You have successfully called the /hello/world controller.");        
        
        // Located at /WEB-INF/jsp/pages/hello-world.jsp
        return "view: hello-world";
    }
}

@Controller
@Request("/hello")
public class HelloWorldController {

    @Request("/world/{id}")
    public String helloWorld(@PathParam Long id) {
        System.out.println("Well done! You can now use the id path parameter in your code. The id is: " + id);

        // Located at /WEB-INF/jsp/pages/hello-world.jsp
        return "view: hello-world";
    }
}

@Controller
@Request("/hello")
public class HelloWorldController {

    @Request("/world/{id}")
    public String helloWorld(@PathParam Long id, @Param String myQueryParam) {
        System.out.println("Thanks, you sent the following query parameter: " + myQueryParam);

        // Located at /WEB-INF/jsp/pages/hello-world.jsp
        return "view: hello-world";
    }
}    

import static com.geemvc.Results.*;

@Controller
@Request("/hello")
public class HelloWorldController {

    protected Service someService;

    @Inject
    protected HelloWorldController(Service someService) {
        this.someService = someService;
    }

    @Request("/world/{id}")
    public Result helloWorld(@PathParam Long id, @Param String myQueryParam) {
        System.out.println("Cool, I am passing the parameter 'myViewParam' to the view!");

        // Results.view() lets you bind parameters to the view.
        return view("hello-world").bind("myViewParam", someService.getById(id));
    }
}

import static com.geemvc.Results.*;

@Controller
@Request("/hello")
public class HelloWorldController {

    protected Service someService;

    @Inject
    protected HelloWorldController(Service someService) {
        this.someService = someService;
    }

    /**
     * Because we have specified the "onError" attribute in the @Request annotation, geeMVC will not enter this
     * handler-method when it detects validation errors. If you want to check for further errors or dynamically
     * forward the user to some view, do not use this. Make use of the "Bindings" object as shown in the example 
     * following this one.
     */
    @Request(path = "/world/{id}", onError="hello-world")
    public Result helloWorld(@Required @PathParam Long id, @Param String myQueryParam) {
        System.out.println("Cool, I am passing the parameter 'myViewParam' to the view!");

        // Located at /WEB-INF/jsp/pages/hello-world.jsp
        return view("hello-world").bind("myViewParam", someService.getById(id));
    }
}

import static com.geemvc.Results.*;

@Controller
@Request("/hello")
public class HelloWorldController {

    protected Service someService;

    @Inject
    protected HelloWorldController(Service someService) {
        this.someService = someService;
    }

    @Request(path = "/world/{id}")
    public Result helloWorld(@Required @PathParam Long id, @Param String myQueryParam, Bindings bindings, Errors errors) {

        // Lets check if validation errors exist.
        if (bindings.hasErrors()) {
            // Optionally we will add another message to the validation errors.
            errors.add("Hey, I also want to add this error message!");
            
            // Now we tell geeMVC where to go in case of a validation error.
            // Located at /WEB-INF/jsp/pages/some-other.jsp.
            return view("some-other").bind("myViewParam", someService.getById(id));
        }

        // Located at /WEB-INF/jsp/pages/hello-world.jsp
        return view("hello-world").bind("myViewParam", someService.getById(id));
    }
}

import static com.geemvc.Results.*;

@Controller
@Request("/hello")
public class HelloWorldController {

    protected Service someService;

    @Inject
    protected HelloWorldController(Service someService) {
        this.someService = someService;
    }

    /**
     * Takes the user to the form page.
     */
    @Request("world-form")
    public String helloWorld() {
        // Located at /WEB-INF/jsp/pages/hello-world-form.jsp
        return "view: hello-world-form";
    }

    /**
     * Attempts to save the form. If a validation error occurs we go back to the form, otherwise we show the success page.
     */
    @Request(path = "save-world-form", method = HttpMethod.POST)
    public Result saveWorld(@Valid WorldBean world, Bindings bindings, Errors errors) {

        // Lets check if validation errors exist.
        if (bindings.hasErrors()) {

            // Now we tell geeMVC where to go in case of a validation error.
            return view("hello-world-form").bind(bindings.typedValues()); // Re-bind values to view.
        }

        if (!worldIsValid(world)) {
            errors.add("World is not valid, please check again.");

            return view("hello-world-form").bind(bindings.typedValues()); // Re-bind values to view.
        }

        // Save the bean.
        WorldBean savedWorld = service.add(world);

        // Located at /WEB-INF/jsp/pages/hello-world-success.jsp
        return view("hello-world-success").bind("savedWorld", savedWorld);
    }
    
    /**
     * Simple check method which could do some evaluation.
     * @param world
     * @return isValid
     */
    protected boolean worldIsValid(WorldBean world) {
        // Some evaluation ...
        return world == null ? false : true;
    }
}

public class WorldBean {

    protected Long id;

    @Required
    @On("/save-world-form")
    protected String name;

    @Check(required = true, minLength = 30, on = "/save-world-form")
    protected String description;

    @NotNull
    protected boolean isHumanLifeSupported;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public boolean isHumanLifeSupported() {
        return isHumanLifeSupported;
    }

    public void setHumanLifeSupported(boolean humanLifeSupported) {
        isHumanLifeSupported = humanLifeSupported;
    }
}

@Controller
@Request("/hello")
public class HelloWorldController {

    @Inject
    protected Cache cache;

    @Inject
    protected Injector injector;

    @Logger
    protected Log log;
    
    // ...
    
    @Request("/world/{id}")
    public String helloWorld(@PathParam Long id) {
    	// Use the logger.
        log.debug("Well done! You can now use the id path parameter in your code. The id is: {}", id);
        
        // Add or retrieve some value from the cache.
        cache.put("my-key", "my-value");

        // Inject your object.
        WorldBean world = injector.getInstance(WorldBean.class);

        return "view: hello-world";
    }
}

@Controller
@Request("/hello")
public class HelloWorldController {

    /**
     * Automatically inject the response object into this handler method.
     */
    @Request("/cookie-test")
    public String cookieTest(HttpServletResponse response) {
        // Add the cookie to the response.
        response.addCookie(new Cookie("my-key", "my-value"));

        // Redirect to some URI.
        return "redirect: /cookie-success";
    }
}

@Intercept
public class TimerInterceptor implements AroundHandler {

    @Logger
    protected Log log;

    @Override
    public Object invokeAround(InvocationContext invocationCtx) {
        long start = System.currentTimeMillis();

        Object o = invocationCtx.proceed();

        log.trace("The request handler '{}' took {}ms.", () -> invocationCtx.requestHandler().toGenericString(), () -> System.currentTimeMillis() - start);

        return o;
    }
}

@PreView(on = {"/form-one", "/form-two", "/form-three"}, onView = OnView.EXISTS, when = When.NO_ERRORS)
public class preViewInterceptor {
    @Inject
    protected Service someService;

    /**
     * Add countries and languages before forwarding to view.
     */
    public void intercept(Result result) {
        result.bind("countries", service.getCountries()).bind("languages", service.getLanguages());
    }
}

@Controller
@Request("/hello")
public class HelloWorldController {

    @Logger
    protected Log log;

    // ....

    @PostValidation(on = {"/save-world-form"}, when = When.HAS_ERRORS)
    public void afterValidation(LifecycleContext lifecycleCtx, Errors errors) {
        log.trace("Validation has found {} errors.", () -> errors.allErrors().size());

        // Do something ...
    }
    
    // ....
    
}