java - 为什么托管 bean 方法在发布请求中的过滤器调用之前调用

Question

我有一个用于设置字符编码过滤器的过滤器。

web.xml:

<filter>
    <filter-name>encodingFilter</filter-name>
    <filter-class>ua.com.winforce.online.site.http.filter.EncodingFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>encodingFilter</filter-name>
    <url-pattern>*.html</url-pattern>
</filter-mapping>
<filter-mapping>
    <filter-name>encodingFilter</filter-name>
    <url-pattern>*</url-pattern>
</filter-mapping>

过滤器本身:

public class EncodingFilter implements Filter {
    private static final String ENCODING = "UTF-8";

    FilterConfig config;

    public void init(FilterConfig filterConfig) throws ServletException {
        this.config = filterConfig;
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
        request.setCharacterEncoding(ENCODING);
        filterChain.doFilter(request, response);
    }

    public void destroy() {
    }
}

一段标记用户提交表单:

<h:form>
    <h:commandLink styleClass="ruski-button green-g full-width" action="#{supportController.save}"  >
    </h:commandLink>
</h:form>

事情是当 post 请求到来时，过滤器的方法 doFilter 在 supportController.save 方法之前调用。但我需要在 supportController.save 调用之前设置字符编码。我怎样才能做到这一点？

Answer 1

更改过滤器映射

<filter-mapping>
    <filter-name>encodingFilter</filter-name>
    <url-pattern>*</url-pattern>
</filter-mapping>

至

<filter-mapping>
    <filter-name>encodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

SRV.11.2 Specification of Mappings

In the web application deployment descriptor, the following syntax is used to define mappings:

• A string beginning with a ‘/’ character and ending with a ‘/*’ postfix is used for path mapping.
• A string beginning with a ‘*.’ prefix is used as an extension mapping.
• A string containing only the ’/’ character indicates the "default" servlet of the application. In this case the servlet path is the
  request URI minus the context path and the path info is null.
• All other strings are used for exact matches only.