JSP错误：ResultSet.last() 调用有问题

Knuuy 2011-07-28 07:16:58



<%@ page contentType="text/html; charset=gb2312" language="java" %>

<%@ page import="java.sql.*" %>

<%@ page import="java.lang.Integer" %>

<%@ page import="java.lang.Math" %>

<%!

//JDBC分页导航函数

public String writeNavigation(ResultSet p_rs,int p_pageSize,int p_pageIndex,int p_totleRS,String p_strURL){



  //定义当前分页开头记录和结束记录号

  int recordHead, recordLast;

  //获得分页数

  int pageCount = (int)Math.ceil((double)p_totleRS/p_pageSize);



  //通过计算获得分页开头记录和结束记录号

  recordHead = 1;

  if (p_pageIndex > 1){

	recordHead = p_pageSize * (p_pageIndex-1) + 1;

  }

  if (p_pageIndex >= pageCount){

    recordLast = p_totleRS;

  } else {

    recordLast = p_pageSize * p_pageIndex;

  } 

  //定义一个字符串用于函数返回值

  String result = "";

  result = result + "<table width=\"600\"><tr><td colspan=\"3\">";

  result = result + "第" + recordHead + "-" + recordLast + "条，共" + p_totleRS + "条，每页显示" + p_pageSize + "条</td></tr>";

   

  //定义翻页变量

  String prevPage = String.valueOf(p_pageIndex - 1);

  String nextPage = String.valueOf(p_pageIndex + 1);

  

  //判断输入的URL是否已经包含有的查询变量

  if (p_strURL.indexOf("?") == -1){

	  p_strURL = p_strURL + "?";

  } else {

	  p_strURL = p_strURL + "&";

  }

  //定义导航条

  String firstPage = "<a href=\"" + p_strURL + "page=1\">[首页]</a> ";

  String lastPage = "<a href=\"" + p_strURL + "page=" + pageCount + "\">[尾页]</a>";

  if (p_pageIndex > 1){

    prevPage = "<a href=\"" + p_strURL + "page=" + prevPage + "\">[上页]</a> ";

  }

  if (p_pageIndex < pageCount){

    nextPage = "<a href=\"" + p_strURL + "page=" + nextPage + "\">[下页]</a> ";

  }

  if (p_pageIndex == pageCount){

    nextPage = "[下页] ";

    lastPage = "[尾页]";

  }

  if (p_pageIndex <= 1){

    prevPage = "[上页] ";

    firstPage = "[首页] ";

  }

  result = result + "<tr align=\"right\"><form name=\"form\" method=\"post\" action=\"" + p_strURL + "\"><td align=\"left\">";

  result = result + "共" + pageCount + "页 " + "目前第"+ p_pageIndex +"页</td><td>";

  result = result + " 到第<input type=\"text\" name=\"page\" size=\"3\" style=\"height:16px; margin-bottom:2px;\" />页<input type=\"submit\" value=\"GO\" style=\"height:18px; margin-bottom:1px;\" />";

  result = result + "</td><td>" + firstPage + prevPage + nextPage + lastPage + "</td></form></tr></table>";

  

  return result; 

}



//JDBC分页数据函数

private String writePagedRS(ResultSet p_rs, int p_pageSize, int p_pageIndex) throws java.sql.SQLException{

  //定义一个字符串用于函数返回值

  String result = "";

  result = result + "<table><tr bgcolor=\"#637E94\">";

  //写结果集字段名

  int columnSize = p_rs.getMetaData().getColumnCount();

  for (int j = 1; j <= columnSize; j++) {

    result = result + "<th width=\"150\">"+ p_rs.getMetaData().getColumnName(j) + "</th>";

  }

  result = result + "</tr>";

	

  //写结果集数据

  int id = 0;

  p_rs.absolute((p_pageIndex-1)*p_pageSize);

  while (p_rs.next() && id < p_pageSize){

    id++;

    if ((id % 2)==0){

      result = result + "<tr bgcolor=\"#E3EAEF\">";

    } else {

      result = result + "<tr bgcolor=\"#ffffff\">";

    }

	for (int j = 1; j <= columnSize; j++) {

      result = result + "<td>"+ p_rs.getObject(j) + "</td>";

    }

    result = result + "</tr>";

  }

  result = result + "</table>";

  

  return result;

}

%>

<%

//pageSize表示每页的记录数

//strURL表示处理分页结果集的文件路径

int pageSize = 3;  //3代表每页显示3条记录

int pageCount; //页数

String strSQL = "SELECT firstName,lastName,EmpType,age FROM employees";

String strURL = "displayByPage.jsp";



Connection myConn = null;

Statement myStatement = null;

ResultSet myResultSet = null;

try{

  Driver myDriver = (Driver)Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver").newInstance();

} catch (ClassNotFoundException e) {

  out.println("数据库驱动程序出错：" + e.getMessage());

}

try{

  myConn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName=myDatabase;user=sa;password=verysecret");

  //注意这里游标的设置

  myStatement = myConn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);

  myResultSet = myStatement.executeQuery("SELECT firstName,lastName,EmpType,age FROM employees");

} catch(SQLException e) {

  out.println("数据库出错：" + e.getMessage());

}

if (!myResultSet.last()){

  out.print("没有记录！");

} else {

  //获得当前要显示的结果集分页码

  int pageIndex = 1;

  try{

    pageIndex = Integer.parseInt(request.getParameter("page"));

  } catch (Exception e) {

    out.print("page出错：" + e);

	pageIndex = 1;

  }



  myResultSet.last();

  int totleRS = myResultSet.getRow();//总记录数

  pageCount = (int)Math.ceil((double)totleRS/pageSize); //分页数

  if (pageIndex == 1 || pageIndex < 1){

    pageIndex = 1;

  } else if (pageIndex > pageCount){

    pageIndex = pageCount;

  } 

  //写分页数据

  out.print(writePagedRS(myResultSet, pageSize, pageIndex));

  //写分页导航信息

  out.print(writeNavigation(myResultSet, pageSize, pageIndex, totleRS, strURL));

}

%>

<%  

//最后，显式的关闭对象

myResultSet.close();

myResultSet = null;

myStatement.close();

myStatement = null;

myConn.close();

myConn = null;  

%>

显示的错误
org.apache.jasper.JasperException: An exception occurred processing JSP page /root/09/9-6.jsp at line 120

117: } catch(SQLException e) {
118: out.println("数据库出错：" + e.getMessage());
119: }
120: if (!myResultSet.last()){
121: out.print("没有记录！");
122: } else {
123: //获得当前要显示的结果集分页码

Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:519)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:428)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

之前写的程序一遇到ResultSet.last(),next(),first()等这些方法时总是有这样的错误org.apache.jasper.JasperException: An exception occurred processing JSP page /root/09/9-6.jsp at line XX对应的行数。是不是软件方面配置有问题啊

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