谁知道servlet的RequestDisPatcher的用法:帮我看看程序
谁知道servlet的RequestDisPatcher的用法:帮我看看程序:
RequestDisPatcher requestDisPatcher = request.getRequestDispatcher("/jsp_servlet_javabean/viewMessage.jsp");
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上面画线的路径应该怎么表示
谁能鲜细的给我说说???
程序的源代码如下:
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
import java.util.*;
import java.io.*;
public class ViewMessageServlet extends HttpServlet
{
private Connection conn;
//接受Get的请求。执行数据库操作,保存到request中,
public void doGet(HttpServletRequest request,HttpServletResponse response)throws IOException,ServletException
{
Collection ret =new ArrayList();
try
{
Statement stm = conn.createStatement();
ResultSet result = stm.executeQuery("select count(*)from message");
int message_count = 0;
if(result.next())
{
message_count = result.getInt(1);
result.close();
}
if(message_count>0)
{
result = stm.executeQuery("select * from message order by time desc");
while(result.next())
{
String title = result.getString("title");
String name = result.getString("name");
String mail = result.getString("mail");
String content = result.getString("content");
java.sql.Date Date = result.getDate("time");
MessageVO message = new MessageVO();
message.setName(name);
message.setTitle(title);
message.setContent(content);
message.setDate(Date);
message.setEmail(mail);
ret.add(message);
}
result.close();
stm.close();
}
//保存执行结果,把试图派发到目标
request.setAttribute("message",ret);
RequestDisPatcher requestDisPatcher = request.getRequestDispatcher("/jsp_servlet_javabean/viewMessage.jsp");
}catch(Exception e)
{
e.printStackTrace();
}
}
//初始化到数据库的连接
public ViewMessageServlet()
{
String classname = "sun.jdbc.odbc.JdbcOdbcDriver";
String strdb = "jdbc:odbc:shang";
String name = "";
String pwd = "";
try
{
Class.forName(classname);
conn = DriverManager.getConnection(strdb,name,pwd);
}catch(Exception e)
{
e.printStackTrace();
}
}
public void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException
{
doGet(request,response);
}
}