3）Filter执行的顺序
马 克-to-win：根据上面的说明“Filter的拦截的工作过程”的图，我们对Filter的Helloworld例子做一个小小的扩展（增加了一个 MarkToWinFilter2，代码和MarkToWinFilter几乎一样），来说明Filter的顺序，结论：filter-mapping在Web.xml中的顺序决定了Filter执行的顺序。
例 1.2.3
Web.xml中增加下一段：
<filter>
<filter-name>MarkToWinFilter2</filter-name>
<filter-class>com.MarkToWinFilter2</filter-class>
</filter>
<filter>
<filter-name>MarkToWinFilter</filter-name>
<filter-class>com.MarkToWinFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>MarkToWinFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>MarkToWinFilter2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
package com;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.*;
public class MarkToWinFilter2 implements Filter {
public void destroy() {
}
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
response.setCharacterEncoding("GBK");
PrintWriter out = response.getWriter();
out.println("之前 filterChain.doFilter2");
System.out.println("之前 filterChain.doFilter2");
chain.doFilter(request, response);
System.out.println("之后 filterChain.doFilter2");
out.println("之后 filterChain.doFilter2");
}
public void init(FilterConfig fConfig) throws ServletException {
}
}
更多请看：https://blog.csdn.net/qq_44638460/article/details/104079515
