利用Spring注解MVC的时候我们发现有两个注解@PathVariable和@RequestParam

举例如下：

http://localhost:8080/api/show/id?id=22

在restful格式中我们采用

http://localhost:8080/api/show/{id}?id=22

这样path上的参数我们就可以通过@PathVariable获取，而参数上的值可以通过@RequestParam获取

针对其具体的属性我们查看源码：

public @interface PathVariable {	/** The URI template variable to bind to. */	String value() default "";}

public @interface RequestParam {	/**	 * The name of the request parameter to bind to.	 */	String value() default "";	/**	 * Whether the parameter is required.	 * 
Default is true, leading to an exception thrown in case	 * of the parameter missing in the request. Switch this to false	 * if you prefer a null in case of the parameter missing.	 * 
Alternatively, provide a {@link #defaultValue() defaultValue},	 * which implicitly sets this flag to false.	 */	boolean required() default true;	/**	 * The default value to use as a fallback. Supplying a default value implicitly	 * sets {@link #required()} to false.	 */	String defaultValue() default ValueConstants.DEFAULT_NONE;}

我们发现@RequestParam有value和required两个属性

使用方式举例如下：

@RequestMapping(value = "/show/{id}", method = RequestMethod.GET)@ResponseBodypublic List
    
      show(@PathVariable String id,	@RequestParam(value = "id", required = false) String uid) {	List
     
       list = new ArrayList
      
       ();	for (int i = 0; i < 10; i++) {		list.add(id + i);	}	return list;}