Spring has a powerful built-in StringUtils class
Notice the following array containing a set of id's
String [] idArray = new String [] {"0", "1", "2", "0", "5", "2"}
And you want to remove duplicate references. Just do it
idArray = StringUtils.removeDuplicateStrings(idArray);
Now idArray will contain {"0", "1", "2", "5"}.
And much more.
Is it possible to use a Controller class without declare them in web application context file?
Yes, just put @Component in its declaration (@Controller does not work as expected)
package br.com.spring.view.controller
@Component
public class PlayerController extends MultiActionController {
private Service service;
@Autowired
public PlayerController(InternalPathMethodNameResolver ipmnr, Service service) {
this.service = service;
setMethodNameResolver(ipmnr);
}
// mapped to /player/add
public ModelAndView add(...) {}
// mapped to /player/remove
public ModelAndView remove(...) {}
// mapped to /player/list
public ModelAndView list(...) {}
}
So in web application context file put the following
<beans ...>
<context:component-scan base-package="br.com.spring.view"/>
<context:annotation-config/>
<bean class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping">
<property name="order" value="0"/>
<property name="caseSensitive" value="true"/>
</bean>
<bean class="org.springframework.web.servlet.mvc.multiaction.InternalPathMethodNameResolver"/>
</beans>
Nothing else
Validation in dynamic forms ?
Use the following
public class Team {
private List<Player> playerList;
}
So in Team validator put
@Component
public class TeamValidator implements Validator {
private PlayerValidator playerValidator;
@Autowired
public TeamValidator(PlayerValidator playerValidator) {
this.playerValidator = playerValidator;
}
public boolean supports(Class clazz) {
return clazz.isAssignableFrom(Team.class);
}
public void validate(Object command, Errors errors) {
Team team = (Team) command;
// do Team validation
int index = 0;
for(Player player: team.getPlayerList()) {
// Notice code just bellow
errors.pushNestedPath("playerList[" + index++ + "]");
ValidationUtils.invokeValidator(playerValidator, player, errors);
errors.popNestedPath();
}
}
}
Inheritance in web forms ?
Use ServlerRequestDataBinder along with hidden form flag
public class Command {
private Parent parent;
}
public class Child extends Parent { ... }
public class AnotherChild extends Parent { ... }
And in your controller do the following
public class MyController extends MultiActionController {
public ModelAndView action(HttpServletRequest request, HttpServletResponse response, Object command) {
Command command = (Command) command;
// hidden form flag
String parentChildType = ServletRequestUtils.getRequiredStringParameter(request, "parentChildType");
// getApplicationContext().getBean(parentChildType) retrieves a Parent object from a application context file
ServletRequestDataBinder binder =
new ServletRequestDataBinder(getApplicationContext().getBean(parentChildType));
// populates Parent child object
binder.bind(request);
command.setParent((Parent) binder.getTarget());
}
Spring has a built-in scanner class ClassPathScanningCandidateComponentProvider. You can use it to find annotations, for instance.
ClassPathScanningCandidateComponentProvider scanner =
new ClassPathScanningCandidateComponentProvider(<DO_YOU_WANT_TO_USE_DEFAULT_FILTER>);
scanner.addIncludeFilter(new AnnotationTypeFilter(<TYPE_YOUR_ANNOTATION_HERE>.class));
for (BeanDefinition bd : scanner.findCandidateComponents(<TYPE_YOUR_BASE_PACKAGE_HERE>))
System.out.println(bd.getBeanClassName());
Spring has a useful org.springframework.util.FileCopyUtils class. You can copy a uploaded file by using
public ModelAndView action(...) throws Exception {
Command command = (Command) command;
MultiPartFile uploadedFile = command.getFile();
FileCopyUtils.copy(uploadedFile.getBytes(), new File("destination"));
If you use a annotation based controller (Spring 2.5+) OR plain MVC Spring controller, you can use a WebBindingInitializer to register global property editors. Something like
public class GlobalBindingInitializer implements WebBindingInitializer {
public void initBinder(WebDataBinder binder, WebRequest request) {
binder.registerCustomEditor(Date.class, new CustomDateEditor(new SimpleDateFormat("dd/MM/yyyy", true);
}
}
So in your web application context file, declare
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<property name="webBindingInitializer">
<bean class="GlobalBindingInitializer"/>
</property>
</bean>
This way any annotation based controller can use any property editor declared in GlobalBindingInitializer.
And so on...
