过滤器配置-优快云博客

本文链接：https://blog.youkuaiyun.com/elia1208/article/details/52065597

本文介绍了一个自定义的请求过滤器实现，该过滤器通过装饰模式包装HttpServletRequest，并覆盖getParameter方法来处理请求参数。此外，文章还展示了如何在web.xml中配置此过滤器。

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1. public class RequestFilter implements Filter{

@Override
public void destroy() {

}

@Override
public void doFilter(ServletRequest sr, ServletResponse rs,
FilterChain chain) throws IOException, ServletException {

HttpServletRequest request = (HttpServletRequest) sr;
HttpServletResponse response = (HttpServletResponse)rs;
request = new RequestHelperWrap(request);
chain.doFilter(request, response);
}

@Override
public void init(FilterConfig config) throws ServletException {

}

}

2.public class RequestHelperWrap extends HttpServletRequestWrapper{

@Override
public String getParameter(String name) {
String value = super.getParameter(name);
if(StringUtil.isBlank(value)){
return null;
}
return StringUtil.trimBlank(value);
}

public RequestHelperWrap(HttpServletRequest request) {
super(request);
}

}

3.web.xml的filter的最前面

<filter>
<filter-name>RequestFilter</filter-name>
<filter-class>com.mst.config.RequestFilter</filter-class>
</filter>

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