<%@ page contentType="text/html;charset=GB2312"%><%@ page language="java" import="java.sql.*,forum.*,conn.*,java.util.*"%><%connectDB bbsconn=new connectDB();String sql="select * from user";Vector y=new Vector();try{ResultSet rs=bbsconn.executeQuery(sql);while(rs.next()){User a=(User) new User();String email=rs.getString("email");String password=rs.getString("password");String username=rs.getString("username");a.setemail(email);a.setpassword(password);a.setusername(username);y.addElement(a);}}catch(Exception e){e.printStackTrace();}Vector list = new Vector();list = y;for(int i=0;i<list.size();i++){User c = (User)y.elementAt(i);String a = c.getemail();String b=c.getpassword();String e=c.getusername();out.print(a+"````````````````````");out.print(b+"`````````````");out.print(e+"<br>");}%>这个是测试数据库连接的JSP文件package conn;import java.sql.*;public class connectDB{String ConnStr="jdbc:mysql://localhost:3036/bbs";String DBUser="root";String DBPassword="";ResultSet rs = null;Statement stm=null;public connectDB(){try{Class.forName("org.gjt.mm.mysql.Driver");stm = DriverManager.getConnection(ConnStr,DBUser,DBPassword).createStatement();}catch(Exception e){e.printStackTrace();}}public ResultSet executeQuery(String sql){try{rs = stm.executeQuery(sql);}catch(SQLException e){return rs;}return null;}public void executeUpdate(String sql){try{stm.executeUpdate(sql);}catch(SQLException ex){ex.printStackTrace();}}}这个是数据库连接类为什么我得不到数据，我数据库里面有资料的<%@ page contentType="text/html;charset=GB2312"%><%@ page language="java" import="java.sql.*,forum.*,conn.*,java.util.*"%><%Class.forName("org.gjt.mm.mysql.Driver").newInstance();Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/bbs","root","");//用户名与密码Statement stmt=conn.createStatement();String sql="select * from user";Vector y=new Vector();try{ResultSet rs=(ResultSet) stmt.executeQuery(sql);while(rs.next()){User a=(User) new User();String email=rs.getString("email");String password=rs.getString("password");String username=rs.getString("username");a.setemail(email);a.setpassword(password);a.setusername(username);y.addElement(a);}}catch(Exception e){e.printStackTrace();}Vector list = new Vector();list = y;for(int i=0;i<list.size();i++){User c = (User)y.elementAt(i);String a = c.getemail();String b=c.getpassword();String e=c.getusername();out.print(a+"***");out.print(b+"***");out.print(e+"<br>");}%>这样可以得到数据，为什么QQ***********在线等
參考答案:连接字符串的端口写错了3036和3306
