springMvc注解@ControllerAdvice，@InitBinder,@CrossOrigin,@CookieValue

@ControllerAdvice  spring3.2提供的新注解，作用：控制器增强

/** * Indicates the annotated class assists a "Controller". * * <p>Serves as a specialization of {@link Component @Component}, allowing for * implementation classes to be autodetected through classpath scanning. * * <p>It is typically used to define {@link ExceptionHandler @ExceptionHandler}, * {@link InitBinder @InitBinder}, and {@link ModelAttribute @ModelAttribute} * methods that apply to all {@link RequestMapping @RequestMapping} methods. * * <p>One of {@link #annotations()}, {@link #basePackageClasses()}, * {@link #basePackages()} or its alias {@link #value()} * may be specified to define specific subsets of Controllers * to assist. When multiple selectors are applied, OR logic is applied - * meaning selected Controllers should match at least one selector. * * <p>The default behavior (i.e. if used without any selector), * the {@code @ControllerAdvice} annotated class will * assist all known Controllers. * * <p>Note that those checks are done at runtime, so adding many attributes and using * multiple strategies may have negative impacts (complexity, performance). * * @author Rossen Stoyanchev * @author Brian Clozel * @author Sam Brannen * @since 3.2 */@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Documented@Componentpublic @interface ControllerAdvice {/** * Alias for the {@link #basePackages} attribute. * <p>Allows for more concise annotation declarations e.g.: * {@code @ControllerAdvice("org.my.pkg")} is equivalent to * {@code @ControllerAdvice(basePackages="org.my.pkg")}. * @since 4.0 * @see #basePackages() */@AliasFor("basePackages")String[] value() default {};/** * Array of base packages. * <p>Controllers that belong to those base packages or sub-packages thereof * will be included, e.g.: {@code @ControllerAdvice(basePackages="org.my.pkg")} * or {@code @ControllerAdvice(basePackages={"org.my.pkg", "org.my.other.pkg"})}. * <p>{@link #value} is an alias for this attribute, simply allowing for * more concise use of the annotation. * <p>Also consider using {@link #basePackageClasses()} as a type-safe * alternative to String-based package names. * @since 4.0 */@AliasFor("value")String[] basePackages() default {};/** * Type-safe alternative to {@link #value()} for specifying the packages * to select Controllers to be assisted by the {@code @ControllerAdvice} * annotated class. * <p>Consider creating a special no-op marker class or interface in each package * that serves no purpose other than being referenced by this attribute. * @since 4.0 */Class<?>[] basePackageClasses() default {};/** * Array of classes. * <p>Controllers that are assignable to at least one of the given types * will be assisted by the {@code @ControllerAdvice} annotated class. * @since 4.0 */Class<?>[] assignableTypes() default {};/** * Array of annotations. * <p>Controllers that are annotated with this/one of those annotation(s) * will be assisted by the {@code @ControllerAdvice} annotated class. * <p>Consider creating a special annotation or use a predefined one, * like {@link RestController @RestController}. * @since 4.0 */Class<? extends Annotation>[] annotations() default {};}

在@ControllerAdvice注解类的内部使用@ExceptionHandler、@InitBinder、@ModelAttribute注解的方法应用到所有的 @RequestMapping注解的方法

@ControllerAdvice  public class ControllerAdviceTest {        @ModelAttribute      public User newUser() {          System.out.println("============应用到所有@RequestMapping注解方法，在其执行之前把返回值放入Model");          return new User();      }        @InitBinder      public void initBinder(WebDataBinder binder) {          System.out.println("============应用到所有@RequestMapping注解方法，在其执行之前初始化数据绑定器");      }        @ExceptionHandler(UnauthenticatedException.class)      @ResponseStatus(HttpStatus.UNAUTHORIZED)      public String processUnauthenticatedException(NativeWebRequest request, UnauthenticatedException e) {          System.out.println("===========应用到所有@RequestMapping注解的方法，在其抛出UnauthenticatedException异常时执行");          return "viewName"; //返回一个逻辑视图名      }  }  

@Target(ElementType.METHOD)@Retention(RetentionPolicy.RUNTIME)@Documentedpublic @interface ExceptionHandler {/** * Exceptions handled by the annotated method. If empty, will default to any * exceptions listed in the method argument list. */Class<? extends Throwable>[] value() default {};}

@ExceptionHandler({UnauthorizedException.class, UnknownAccountException.class, UnauthenticatedException.class, AuthenticationException.class})    public String processShiroExceptions() {        return "403";    }

  @InitBinder标识的方法,可以对 WebDataBinder 对象进行初始化。WebDataBinder 是 DataBinder 的子类,用于完成由表单字段到 JavaBean 属性的绑定。
• @InitBinder方法不能有返回值,它必须声明为void。
• @InitBinder方法的参数通常是是 WebDataBinder。

@InitBinder      public void initBinder(WebDataBinder binder){          //TODO    }  

http://blog.csdn.net/axin66ok/article/details/17938095

在SpringMVC中，bean中定义了Date，double等类型，如果没有做任何处理的话，日期以及double都无法绑定。
解决的办法就是使用spring mvc提供的@InitBinder标签，可以在BaseController中增加方法initBinder，并使用注解@InitBinder标注，那么spring mvc在绑定表单之前，都会先注册这些编辑器，当然你如果不嫌麻烦，你也可以单独的写在你的每一个controller中。剩下的控制器都继承该类。spring自己提供了大量的实现类，诸如CustomDateEditor ，CustomBooleanEditor，CustomNumberEditor等许多，基本上够用。

@InitBinder       protected void initBinder(WebDataBinder binder) {           binder.registerCustomEditor(Date.class, new CustomDateEditor(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"), true));    /        binder.registerCustomEditor(int.class, new CustomNumberEditor(int.class, true));           binder.registerCustomEditor(int.class, new IntegerEditor());    /        binder.registerCustomEditor(long.class, new CustomNumberEditor(long.class, true));         binder.registerCustomEditor(long.class, new LongEditor());           binder.registerCustomEditor(double.class, new DoubleEditor());           binder.registerCustomEditor(float.class, new FloatEditor());       }   

@InitBinder    protected void initBinder(WebDataBinder binder) {        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");        binder.registerCustomEditor(Timestamp.class, new CustomDateEditor(dateFormat, true));    }

@CrossOrigin用来处理跨域请求

@CookieValue 可让处理方法入参绑定某个 Cookie 值

@RequestMapping("/springmvc")  @Controller  public class HelloWorld {  @RequestMapping("/testCookieValue")      public String testCookieValue(@CookieValue("JSESSIONID")String sessionId){          System.out.println("testCookieValue: "+sessionId);          return "success";      }  }  

@ModelAttribute 被此注解注解的方法会在此controller每个方法执行前被执行，因此对于一个controller映射多个URL的用法来说，要谨慎使用

@RequestMapping("index1")    @ResponseBody    public Object inde1x(Model model){        return "sss";    }    @ModelAttribute//abc这个    public void populateModel(@RequestParam String abc, Model model) {        model.addAttribute("attributeName", abc);    }

@RequestMapping("index1")    @ResponseBody    public Object inde1x(@ModelAttribute("userPojo") UserPojo userPojo){        return "sss";    }    @ModelAttribute("userPojo")    //UserPojo这个类    public UserPojo addPojo(@RequestParam String userName) {        return new UserPojo(userName);    }

@ModelAttribute("attributeName")    public String addAccount(@RequestParam String abc) {        //在model中增加key=attributeName,value=abc(由浏览器传过来而定)的键值对        return abc;    }

@RequestMapping(value = "/helloWorld")    @ModelAttribute("attributeName")    public String helloWorld() {        //这时这个方法的返回值并不是表示一个视图名称，而是model属性的值(key=attributeName,value=hi)，视图名称由RequestToViewNameTranslator根据请求"/helloWorld"转换为逻辑视图helloWorld。        return "hi";    }