Struts2-在action中获取表单提交的参数

    <form action="<%=path %>/FirstAction" method="post">
        <input type="text" name="username">
        <input type="submit" name="提交">
    </form>

package com.action;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.ServletActionContext;

public class FirstAction {
    private String username;
    
    public String execute(){
        HttpServletRequest request = ServletActionContext.getRequest();
        username = request.getParameter("username");        
        System.out.println(username);
        return null;        
    }
}