package  student.taglib;

import  javax.servlet.jsp.tagext.TagSupport;
import  java.sql.ResultSet;
import  student.DBBean;


/**
 * put your documentation comment here
 */
public class GoodsHeaderTag extends TagSupport {
    public ResultSet resultset;
    String sqlstring;

    /**
     * put your documentation comment here
     */
    public ResultHeaderTag () {
        resultset = null;
        sqlstring = "SELECT id,name,price,vendor FROM goods";
    }

    /**
     * put your documentation comment here
     * @return
     */
    public int doStartTag () {
        query();
        return  EVAL_BODY_INCLUDE;
    }

    /**
     * put your documentation comment here
     * @return
     */
    public int doAfterBody () {
        try {
            if(resultset.isAfterLast()){
              return SKIP_BODY;// 输出完毕则继续往下执行
            }else{
              resultset.next();
              return EVAL_BODY_AGAIN;//还有未输出，重新对其body content计值
            }
            }
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
        return  SKIP_BODY;
    }

    /**
     * put your documentation comment here
     * @return
     */
    public int doEndTag () {
        try {
            resultset.close();
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
        return  EVAL_PAGE;
    }

    public ResultSet query(){
    	DBBean dbbean = new DBBean(sqlstring);
        resultset = dbbean.query();
    }
  
}