SpringMVC常用注解

@RequestParam

@Target({ElementType.PARAMETER}) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface RequestParam { @AliasFor("name") String value() default ""; @AliasFor("value") String name() default ""; boolean required() default true; String defaultValue() default "\n\t\t\n\t\t\n\ue000\ue001\ue002\n\t\t\t\t\n"; }

使用场景 传递的参数必须和RequestParam的value一致，但不存在这个参数的时候，默认会报错，如果这个参数并非必须，那么可以将@RequestParam的required设置false，age的类型最好为Integer,这样当age参数不存在的时候，会保存，因为不能将null赋给int，如果非要用int,那么可以加defaultValue属性给个默认值

public String testRequestParam(@RequestParam(value = "username") String un, @RequestParam(value = "age",required=false,defaultValue = "0") int age)

@RequestHeader

@Target({ElementType.PARAMETER}) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface RequestHeader { @AliasFor("name") String value() default ""; @AliasFor("value") String name() default ""; boolean required() default true; String defaultValue() default "\n\t\t\n\t\t\n\ue000\ue001\ue002\n\t\t\t\t\n"; }

使用

@RequestMapping(value = "/testRequestHeader") public String requestHeader(@RequestHeader(value = "Accept-Language") String header ,String name){ System.out.println("header: "+header); System.out.println("name "+name); return "info"; }

@CookieValue

@Target({ElementType.PARAMETER}) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface CookieValue { @AliasFor("name") String value() default ""; @AliasFor("value") String name() default ""; boolean required() default true; String defaultValue() default "\n\t\t\n\t\t\n\ue000\ue001\ue002\n\t\t\t\t\n"; }

使用

@RequestMapping(value = "/testCookieValue") public String testCookieValue(@CookieValue(value = "JSESSIONID") String sessionId){ System.out.println("sessionId: "+sessionId); return "info"; }