给Spring MVC增加一个referer View

开发中很常见的一个用例，操作完成后返回操作页面。

用代码表示就是：

response.sendRedirect(request.getHeader("referer"));

spring MVC里有RedirectView，如果能够把referer带上就更方便了。好在spring很灵活，自己增加这个功能吧。

实现一个View接口：

public class RefererRedirectView implements View{
	
	protected static final Log logger = LogFactory.getLog(RefererRedirectView.class);

	/* (non-Javadoc)
	 * @see org.springframework.web.servlet.View#getContentType()
	 */
	public String getContentType() {
		return null;
	}

	/* (non-Javadoc)
	 * @see org.springframework.web.servlet.View#render(java.util.Map, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
	 */
	public void render(Map model, HttpServletRequest request,
			HttpServletResponse response) throws Exception {

		String returnUrl = request.getHeader("referer");
		if(returnUrl==null || returnUrl.trim().equals("")){
			returnUrl = "/";
		}
		logger.debug("referer url["+returnUrl+"]");
		response.sendRedirect(returnUrl);
	}

}

 

ViewResolver 这个接口的实例可以在spring容器里有多个，组成一个链式结构，第一个如果无法处理转交下一个，直到被处理或全部失败。

再实现一个ViewResolver接口：

public class RefererViewResolver implements ViewResolver,Ordered {
	
	protected Log logger = LogFactory.getLog(getClass());
	//以referer:起始的viewName，将被此ViewResolver处理
	public static final String REFERER_PROFIX = "referer:";

	/* (non-Javadoc)
	 * @see org.springframework.web.servlet.ViewResolver#resolveViewName(java.lang.String, java.util.Locale)
	 */
	public View resolveViewName(String viewName, Locale locale)
			throws Exception {
				if (!viewName.startsWith(REFERER_PROFIX)) {
						return null;
		}
		logger.debug("this is referer view.");
		return new RefererRedirectView();
	}

	/* (non-Javadoc)
	 * @see org.springframework.core.Ordered#getOrder()
	 */
	public int getOrder() {
		return Integer.MAX_VALUE-1;//这个ViewResolver排在UrlBasedViewResolver前一个的位置
	}

}

 最后，在配置文件中声明这个viewResolver：

<bean class="com.........RefererViewResolver"/>

 这样，凡是以referer:起始的viewName，都会被redirect到请求发起的页面。

附测试类：

@Controller
public class SomeController {

	@RequestMapping("/test_referer.do")
	public String referer(){
		System.out.println("do some thing ,then return to referer.");
		return "referer:";
	}
	
	@RequestMapping("/test_test1.do")
	public String test1(){
		return "front/user/test1";
	}
	
	@RequestMapping("/test_test2.do")
	public String test2(){
		return "front/user/test2";
	}
}