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#2
cx5210072007-12-06 02:07
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掉弟最近刚开始学servlet想问问这么写那里不对
package
import
import
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.sql.*;
public class login extends HttpServlet {
private String forname;
private String url;
private String user;
private String pwd;
/**
* Constructor of the object.
*/
public login() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
try{
Class.forName(forname);
Connection conn=DriverManager.getConnection(url,user,pwd);
Statement st=conn.createStatement();
String sql="SELECT COUNT(*) FROM luntan";
ResultSet rt=st.executeQuery(sql);
if(rt.next()){
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.print("Welcome:"+request.getParameter("username"));
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}else{
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.print("用户名或密码错误,请重新输入");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
}catch(Exception e){
e.printStackTrace();
}
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request,response);
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occure
*/
public void init() throws ServletException {
forname=getInitParameter("forname");
url=getInitParameter("url");
user=getInitParameter("user");
pwd=getInitParameter("pwd");
}
}
