core 跨越请求 SSH框架

首先我们来了解一下，core 请求的原理：

core方式简单来说它用到的是过滤器，通过过滤器来配置response，

重点，过滤器的在web.xml的位置也起着重要影响，按自己的需求来处理

详细如下：

（1）如果想过滤action 请求来跨越

那么这个过滤器就要继承structs的过滤器，代码如下

web.xml配置过滤器信息

<filter>
   <filter-name>AjaxFilter</filter-name>
    <filter-class>com.gxuwz.core.util.AjaxFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>AjaxFilter</filter-name>
    <url-pattern>/biz/*</url-pattern>   <!--  这里过滤的是带/biz/的请求，例如<%=path%>/biz/test_method.action -->
</filter-mapping>

AjaxFilter过滤器代码

package com.gxuwz.core.util;
 
import java.io.IOException;
 
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter;
public class AjaxFilter extends StrutsPrepareAndExecuteFilter {    //这里继承了structs的过滤器
protected final Log logger = LogFactory.getLog(getClass());
    public void destroy() {
    
    }
    public void doFilter(ServletRequest req, ServletResponse res,
            FilterChain chain) throws IOException, ServletException {
         HttpServletRequest request = (HttpServletRequest) req;
         HttpServletResponse response = (HttpServletResponse) res;
         response.setHeader("Access-Control-Allow-Origin","*");
         response.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, Cookie");
         response.setHeader("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT, DELETE, TRACE, OPTIONS, PATCH");
         response.setHeader("Access-Control-Allow-Credentials", "true");
         chain.doFilter(request, response);
    }
    public void init(FilterConfig arg0) throws ServletException { }
}

提示：建议在web.xml中把这个过滤器放在structs过滤器的前面。这个过滤器继承了structs过滤器只对action请求进行过滤。

如果想过滤全部请求，就不要继承structs过滤器。

但我建议两个都写，只是位置要改变（web.xml）

例如：（假设）

<filter>
   <filter-name>1</filter-name>
    <filter-class>url</filter-class>
</filter>
<filter-mapping>
    <filter-name>1</filter-name>
    <url-pattern>/biz/*</url-pattern>   <!--  这里过滤的是带/biz/的请求，例如<%=path%>/biz/test_method.action -->
</filter-mapping>

    <filter>                                                          <!--structs 特有过滤器 不需要自己写 -->
        <filter-name>struts2</filter-name>
        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <filter>

<filter>
   <filter-name>2</filter-name>
    <filter-class>url</filter-class>
</filter>
<filter-mapping>
    <filter-name>2</filter-name>
    <url-pattern>/biz/*</url-pattern>   <!--  能过滤全部请求的过滤器 -->
</filter-mapping>

这里我提供一个  能过滤全部请求的过滤器

package com.gxuwz.core.util;
 
import java.io.IOException;
import java.net.URL;
 
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import org.apache.commons.lang3.StringUtils;
import org.springframework.web.filter.OncePerRequestFilter;
 
public class CrossDomainFilter extends OncePerRequestFilter {
    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
        String referer = request.getHeader("referer");
        if (StringUtils.isNotBlank(referer)) {
            URL url = new URL(referer);
            String origin = url.getProtocol() + "://" + url.getHost();
            response.addHeader("Access-Control-Allow-Origin", origin);
        } else {
            response.addHeader("Access-Control-Allow-Origin", "*");
        }
        response.addHeader("Access-Control-Allow-Credentials", "true");
        response.addHeader("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE");
        response.addHeader("Access-Control-Allow-Headers", "Content-Type");
        filterChain.doFilter(request, response);
    }
}