WebSphere 7：修改静态内容文件服务的HTTP头

Question

我正在使用WebSphere Application Server v7.0的<enable-file-serving value="true" />功能为我的Java Web应用程序提供静态内容（图像，CSS，JavaScript）。

如何修改此静态内容的HTTP标头（例如，添加Cache-Control或Expires标头）？

Answer 1

我最终编写了一个Filter以基于请求的资源的URL添加HTTP标头。下面是一个简化版本：

CacheFilter.java

public class CacheFilter implements Filter { 
    private static long maxAge = 86400 * 30; // 30 days in seconds 

    @Override 
    public void doFilter(ServletRequest request, ServletResponse response, 
      FilterChain chain) throws IOException, ServletException { 
     HttpServletResponse httpResponse = (HttpServletResponse) response; 
     httpResponse.setHeader("Cache-Control", "max-age=" + maxAge); 
     chain.doFilter(request, response); 
    } 

    @Override 
    public void init(FilterConfig filterConfig) throws ServletException { 
    } 

    @Override 
    public void destroy() { 
    } 
} 

的web.xml

<filter> 
    <filter-name>cache</filter-name> 
    <filter-class>com.example.CacheFilter</filter-class> 
</filter> 
<filter-mapping> 
    <filter-name>cache</filter-name> 
    <url-pattern>*.png</url-pattern> 
</filter-mapping> 
<filter-mapping> 
    <filter-name>cache</filter-name> 
    <url-pattern>*.jpg</url-pattern> 
</filter-mapping> 
<filter-mapping> 
    <filter-name>cache</filter-name> 
    <url-pattern>*.gif</url-pattern> 
</filter-mapping>