myservlet.java

applet客户端通过url访问实现对底层数据库的数据捞取

import java.io.*;
import java.text.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
public class MyServlet extends HttpServlet 
{

    public void doGet(HttpServletRequest request,
                      HttpServletResponse response)
        throws IOException, ServletException
    {
    	try
    	{
    	
        response.setContentType("text/xml");
        PrintWriter out = response.getWriter();
		
		String sql = request.getParameter("sql");
		
       	Class.forName("oracle.jdbc.OracleDriver");
		Connection con = DriverManager.getConnection(
				"jdbc:oracle:thin:@127.0.0.1:1521:school", "scott", "tiger");

		Statement stmt = con.createStatement();
		ResultSet rs = stmt.executeQuery(sql);
		StringBuffer buf = new StringBuffer();
		
        buf.append("<?xml version='1.0' encoding='gb2312'?>");
        buf.append("<root>");
		
		while(rs.next())
		{
			buf.append("<row>");
			for(int i=0; i<rs.getMetaData().getColumnCount(); i++)
			{
				buf.append("<col>"+rs.getString(i+1)+"</col>");
			}
			buf.append("</row>");
		}
		
		buf.append("</root>");
		out.print(buf.toString());
		stmt.close();
		con.close();
		}catch(Exception e)
		{
			System.out.print(e.getMessage());
		}
    }
}