找不到符号

Question

DBHelper。JAVA

package com.control;    
import java.sql.*;    
public class DBHelper 
{
Connection conn;
Statement st;
ResultSet rs;
public DBHelper()throws ClassNotFoundException
{
    Class.forName("oracle.jdbc.driver.OracleDriver");
}

public boolean getConnection()throws SQLException
{
    conn=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","system","system");
    if(conn!=null)
        return true;
    return false;
}

public void execute(String query)throws SQLException
{
    st=conn.createStatement();
    st.execute(query);

}
public boolean match(String uname,String pwd)throws Exception
{
    st=conn.createStatement();
    rs=st.executeQuery("select * from register");


        while(rs.next())
        {
            String unm=rs.getString(1);
            String pd=rs.getString(2);
            if(uname.equals(unm) && pwd.equals(pd))
            {
                return true;
            }

        }
        return false;


}



}

LoginSevlet.java

package com.control;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.sql.*;
public class LoginServlet extends HttpServlet
{


    public void doPost(HttpServletRequest req,HttpServletResponse res)throws IOException,ServletException
    {
        try{
        DBHelper obj=new DBHelper();
        obj.getConnection();
        PrintWriter out=res.getWriter();
        res.setContentType("text/html");
        String uname=req.getParameter("email");
        String pwd=req.getParameter("password");
        //ResultSet rs=obj.match(uname,pwd);
        //if(uname.equals(rs.getString(1)) && pwd.equals(rs.getString(2)))
        if(obj.match(uname,pwd))
        {
            RequestDispatcher rd=req.getRequestDispatcher("profile.html");
            rd.forward(req,res);

        }
        else
        {

            RequestDispatcher rd=req.getRequestDispatcher("index.html");
            rd.include(req,res);
            out.println("<b>Incorrect Email or password!</b>");
        }

        }catch(Exception e)
        {

        }

    }    
}

我正在尝试访问LoginServlet中的DBHelper类，而编译i做了javac DBHelper.javajavac-cp"C：\User\dell\Desktop\MYServlet\WEB-INF\lib\servlet-api-2.5.jar；"LoginServlet.javaLoginServlet.java:13：错误：找不到符号
DBHelper obj=new DBHelper（）；
^
符号：class DBHelper
位置：class LoginServlet
LoginServlet.java:13：错误：找不到符号
DBHelper obj=new DBHelper（）；
^
符号：class DBHelper
位置：class LoginServlet
2错误
我已经将. java文件放在C：\User\dell\Desktop\MYServlet\WEB-INF\class\com\control
所有的文件都在同一个包中，那太公开了，那么为什么不能LoginServlet访问DBHelper类

Answer 1

因为你没有导入com。控制。* 在你的类中LoginServlet。更多关于Java软件包的信息，请尝试在使用软件包时使用正确的命令来编译和执行。