如何在Spring MVC中设置缓存头？

Question

在基于注释的Spring MVC控制器中,为特定路径设置缓存头的首选方法是什么？

Answer 1

我刚遇到同样的问题,并找到了框架已经提供的一个很好的解决方案.该org.springframework.web.servlet.mvc.WebContentInterceptor级允许你定义默认缓存行为,再加上特定的路径覆盖(与其他地方使用相同的路径,匹配的行为).我的步骤是:

1. 确保我的实例org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter没有设置"cacheSeconds"属性.

2. 添加以下实例WebContentInterceptor:

   <mvc:interceptors>
   ...
   <bean class="org.springframework.web.servlet.mvc.WebContentInterceptor" p:cacheSeconds="0" p:alwaysUseFullPath="true" >
       <property name="cacheMappings">
           <props>
               <!-- cache for one month -->
               <prop key="/cache/me/**">2592000</prop>
               <!-- don't set cache headers -->
               <prop key="/cache/agnostic/**">-1</prop>
           </props>
       </property>
   </bean>
   ...
   </mvc:interceptors>
   

在这些更改之后,/ foo下的响应包括阻止缓存的标头,/ cache/me下的响应包括鼓励缓存的标头,以及/ cache/agnostic下的响应包括没有缓存相关的标头.

如果使用纯Java配置:

@EnableWebMvc
@Configuration
public class WebMvcConfig extends WebMvcConfigurerAdapter {
  /* Time, in seconds, to have the browser cache static resources (one week). */
  private static final int BROWSER_CACHE_CONTROL = 604800;

  @Override
  public void addResourceHandlers(ResourceHandlerRegistry registry) {
    registry
     .addResourceHandler("/images/**")
     .addResourceLocations("/images/")
     .setCachePeriod(BROWSER_CACHE_CONTROL);
  }
}

另见:http://docs.spring.io/spring-security/site/docs/current/reference/html/headers.html

Answer 2

答案很简单:

@Controller
public class EmployeeController {

    @RequestMapping(value = "/find/employer/{employerId}", method = RequestMethod.GET)
    public List getEmployees(@PathVariable("employerId") Long employerId, final HttpServletResponse response) {
        response.setHeader("Cache-Control", "no-cache");
        return employeeService.findEmployeesForEmployer(employerId);
    }

}

上面的代码显示了您想要实现的目标.你必须做两件事.添加"final HttpServletResponse response"作为参数.然后将标头Cache-Control设置为no-cache.

Answer 3

org.springframework.web.servlet.support.WebContentGenerator,它是所有Spring控制器的基类,有很多处理缓存头的方法:

/* Set whether to use the HTTP 1.1 cache-control header. Default is "true".
 * <p>Note: Cache headers will only get applied if caching is enabled
 * (or explicitly prevented) for the current request. */
public final void setUseCacheControlHeader();

/* Return whether the HTTP 1.1 cache-control header is used. */
public final boolean isUseCacheControlHeader();

/* Set whether to use the HTTP 1.1 cache-control header value "no-store"
 * when preventing caching. Default is "true". */
public final void setUseCacheControlNoStore(boolean useCacheControlNoStore);

/* Cache content for the given number of seconds. Default is -1,
 * indicating no generation of cache-related headers.
 * Only if this is set to 0 (no cache) or a positive value (cache for
 * this many seconds) will this class generate cache headers.
 * The headers can be overwritten by subclasses, before content is generated. */
public final void setCacheSeconds(int seconds);

它们可以在内容生成之前在控制器中调用,也可以在Spring上下文中指定为bean属性.

Answer 4

从Spring 4.2开始,您可以这样做:

import org.springframework.http.CacheControl;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import java.util.concurrent.TimeUnit;

@RestController
public class CachingController {
    @RequestMapping(method = RequestMethod.GET, path = "/cachedapi")
    public ResponseEntity<MyDto> getPermissions() {

        MyDto body = new MyDto();

        return ResponseEntity.ok()
            .cacheControl(CacheControl.maxAge(20, TimeUnit.SECONDS))
            .body(body);
    }
}

CacheControlobject是具有许多配置选项的构建器,请参阅JavaDoc

Answer 5

您可以使用Handler Interceptor并使用它提供的postHandle方法:

http://static.springsource.org/spring/docs/2.0.x/api/org/springframework/web/servlet/HandlerInterceptor.html

postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) 

然后在方法中添加如下标题:

response.setHeader("Cache-Control", "no-cache");

Answer 6

我发现WebContentInterceptor这是最简单的方法。

@Override
public void addInterceptors(InterceptorRegistry registry)
{
    WebContentInterceptor interceptor = new WebContentInterceptor();
    interceptor.addCacheMapping(CacheControl.noCache(), "/users", "admin");
    registry.addInterceptor(interceptor);
}