求一个RowSet的例子

Question

import java.io.*;
import java.net.*;
import java.sql.*;
import com.sun.rowset.*;
import javax.sql.rowset.*;
import java.util.*;
import java.awt.geom.*;
public class Req 
{ public static void main(String args[])
{
try
{
URL url = new URL("http://localhost/workingroom/exapplet/PostToApplet?DBSQL=Select%20*%20from%20rkmx");
        //注意url中的空格用%20替代/exapplet/PostToApplet
        URLConnection urlcon = url.openConnection();
        urlcon.connect();
           
        ObjectInputStream ois=new ObjectInputStream(urlcon.getInputStream());
        CachedRowSetImpl crs = (CachedRowSetImpl)ois.readObject();
        
        
        ois.close();
        ResultSetMetaData rsmd = (ResultSetMetaData)crs.getMetaData();
            int columnCount = rsmd.getColumnCount();
            
if(crs.next())
{
            for(int k = 1; k < columnCount + 1; k ++)
            {
             System.out.println(crs.getString(k));
            }
            }
            crs.close();
            System.out.println("Changed");
}
catch(Exception ex)
{
ex.printStackTrace();
}
}
}
在tomcat下新建一工程，在server.xml中添加如下语句
<Context path="/workingroom" docBase="D:\WorkingRoom" debug="0" reloadable="true"/>
然后在D盘根目录下新建一文件夹名字叫WorkingRoom然后在该目录下建立文件夹WEB-INF(注意必须为大写),接着在该目录下建立文件夹classes和文件web.xml
其中web.xml文件内容为
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN" "http://java.sun.com/j2ee/dtds/web-app_2_2.dtd">
<web-app>
 <servlet>
        <servlet-name>MyServlet</servlet-name>
        <servlet-class>exapplet.MyServlet</servlet-class>
 </servlet>
 <servlet-mapping>
        <servlet-name>MyServlet</servlet-name>
        <url-pattern>/exapplet/MyServlet</url-pattern>
 </servlet-mapping>
</web-app>

Answer 1

然后在classes目录下继续建一文件夹名称为exapplet接着在该文件夹下面建立名称为MyServlet.java的程序，内容为：
package exapplet;import com.sun.rowset.*;
import javax.sql.rowset.*;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.sql.*;
import javax.servlet.ServletException;
import javax.servlet.http.*;public class MyServlet extends HttpServlet
{    public void doGet(HttpServletRequest httpservletrequest,   
        HttpServletResponse httpservletresponse)
        throws ServletException, IOException
    {
        System.out.println("Start");
        try
        {
            String s = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=gysys";
            Connection connection = DriverManager.getConnection(s, "sa", "");
            Statement statement = connection.createStatement();    String s1 = httpservletrequest.getParameter("DBSQL");
   ResultSet resultset = statement.executeQuery(s1);
   CachedRowSetImpl cachedrowsetimpl = new CachedRowSetImpl();
   cachedrowsetimpl.populate(resultset);
   resultset.close();
   statement.close();
   connection.close();
   httpservletresponse.setContentType("application/octet-stream");
   ObjectOutputStream objectoutputstream = new ObjectOutputStream(httpservletresponse.getOutputStream());
            
   objectoutputstream.writeObject(cachedrowsetimpl);
   System.out.println("before");
   while(cachedrowsetimpl.next())
   {
       System.out.println(cachedrowsetimpl.getString(1));
       System.out.println(cachedrowsetimpl.getString(2));
       System.out.println(cachedrowsetimpl.getString(3));
       System.out.println("in");
   }         
   objectoutputstream.close();
        }
        catch(Exception exception)
        {
            exception.printStackTrace();
        }
    }    public String getServletInfo()
    {
        return "A simple Servlet!";
    }    static 
    {
        try
        {
            Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
        }
        catch(Exception exception)
        {
            exception.printStackTrace();
        }
    }
}
编译之后，启动tomacat,然后运行Req即可看到结果！
祝好运！

Answer 2

CachedRowSetImpl是什么?RowSet和ResultSet有什么区别?

Answer 3

缓存行集，你看他的单词，cache就知道是什么了

Answer 4

CachedRowSetImpl是关键字吗在JBUILDER中不认,import com.sun.rowset.*;中没有*这个项.

Answer 5

package pz;
import javax.sql.RowSet.*;
import java.sql.*;
import com.sun.rowset.*;
import java.util.*;
public class lgrowset
{
public static void main(String[] args)
{
try
{
Connection conn =null;
                  Statement stmt=null;
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance(); 
   String url="jdbc:microsoft:sqlserver://192.168.180.31:1433;DatabaseName=ht_htcw"; 
String user="sa"; 
  String password="12345678"; 
   conn= DriverManager.getConnection(url,user,password); 
   stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE); 
   String sql="select * from zwpzmb";
   ResultSet rs= stmt.executeQuery(sql);
                  CachedRowSetImpl cachedrowsetimpl = new CachedRowSetImpl();
                           CachedRowSetImpl.populate(rs);
   System.out.println("数据库连接成功！");
}
catch(Exception e)
{
System.out.println(e);
System.out.println("数据库连接失败！");
     }
}
}
为什么没有populate(rs)方法,程序这样写对吗?

Answer 6

要导入import javax.sql.rowset.*;不是import javax.sql.RowSet.*;

Answer 7

package pz;
import javax.sql.rowset.*;
import java.sql.*;
import javax.sql.*;
import com.sun.rowset.*;
import java.util.*;
public class lgrowset
{
public static void main(String[] args)
{
try
{
                         CachedRowSetImpl cachedrowsetimpl=new CachedRowSetImpl();
                  String Sql="select * from zwpzmb";
                  cachedrowsetimpl.setUrl("jdbc:microsoft:sqlserver://192.168.180.31:1433;DatabaseName=ht_htcw");
          cachedrowsetimpl.setUsername("sa");
          cachedrowsetimpl.setPassword("12345678");
          cachedrowsetimpl.setCommand(Sql);
          cachedrowsetimpl.execute();
          while(cachedrowsetimpl.next())
                {
                     System.out.println(cachedrowsetimpl.getString(1));
                     System.out.println(cachedrowsetimpl.getString(2));
                     System.out.println(cachedrowsetimpl.getString(3));
                     System.out.println("in");
                }         
         System.out.println("数据库连接成功！");
}
catch(Exception e)
{
System.out.println(e);
System.out.println("数据库连接失败！");
              }
}
}
报了如下错误:
java.sql.SQLException: No suitable driver
数据库连接失败！
数据库驱动包我已经加上了,已经用它做了一个项目了,肯定没有问题,为什么driver错误?这是怎么回事?

Answer 8

                  CachedRowSetImpl cachedrowsetimpl = new CachedRowSetImpl();
                           CachedRowSetImpl.populate(rs);
你这里就错了嘛                   CachedRowSetImpl cachedrowsetimpl = new CachedRowSetImpl();
                           cachedrowsetimpl.populate(rs);

Answer 9

这个错我找到了.
java.sql.SQLException: No suitable driver是怎么回事?

Answer 10

没有JDBC驱动啊，还能会是怎么回事

Answer 11

JDBC驱动应该怎么加啊,不就是加上SQLSERVER(我用的是SQLSERVER数据库)的三个包吗?

Answer 12

你第一段程序的错误在于
CachedRowSetImpl cachedrowsetimpl = new CachedRowSetImpl();
CachedRowSetImpl.populate(rs);
这里，你说找到了，
你第于段程序的错误在于
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance(); 
这句没加

Answer 13

怎么添加addRowSetListener事件监听这句话应该怎么写.
那个事件的实现应该写在哪,是main里面吗?