package BasicAndDontKnow; /* * 动态调用中的this指的是上一级的类 * * */ public class HttpServlet { private HttpServlet aString; public void service(){ System.out.println("HttpServlet.service()"); System.out.println("HttpServlet this:"+this); doGet(); } public void doGet(){ System.out.println("HttpServlet.doGet"); } public String toString() { //aString=this;/////////////////why 报错 return "HttpServlet aString=" + aString + "]"; } }