谁给我看看这代码有什么问题？？？

Question

逻辑错误，你这样写在有记录的情况下打成out.print("<script>alert('无此帐号，请重新输入');javascrpt:history.go(-1);</script>"); 了。

Answer 1

那为什么我把if (！rs.next())该为if (rs.next())后，查询的时候怎么输出
javax.servlet.ServletException: No operations allowed after statement closed.
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:825)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:758)
org.apache.jsp.delete_jsp._jspService(delete_jsp.java:163)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
root cause java.sql.SQLException: No operations allowed after statement closed.
com.mysql.jdbc.Statement.checkClosed(Statement.java:277)
com.mysql.jdbc.Statement.executeQuery(Statement.java:870)
org.apache.jsp.delete_jsp._jspService(delete_jsp.java:143)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)