useBean 调用类时,遇到错误 ,如何终止,并返回信息给用户!
package   com;
import   java.sql.*;
import   db.*;
public   class   newManage
{
ConnDB   con=   new   ConnDB();
private   String   userid,password,qy,username,bm,job,type;

public   void   setUserid(String   u){userid=u;}
public   String   getUserid(){return   userid;}

public   void   setPassword(String   p){password=p;}
public   String   getPassword(){return   password;}

public   void   setQy(String   q){qy=q;}
public   String   getQy(){return   qy;}

public   void   setUsername(String   n){username=n;}
public   String   getUsername(){return   username;}

public   void   setBm(String   b){bm=b;}
public   String   getBm(){return   bm;}

public   void   setJob(String   j){job=j;}
public   String   getJob(){return   job;}

public   void   setType(String   t){type=t;}
public   String   getType(){return   type;}

/***********************************************************************
  *函   数   名:updateDatabase  
  *功能描述:添加管理员帐号
  ***********************************************************************/
public   void   updateDatabase(){

// 定义链接的conn对象
Connection   conn=null;

try   {
//     打开数据库连接
conn=con.mygetConn();

//     数据判断
if   (userid!=null)
userid   =   new   String(userid.getBytes( "ISO-8859-1 "),   "GBK ");
else
userid= "未知 ";

if   (qy!=null)  
qy   =   new   String(qy.getBytes( "ISO-8859-1 "),   "GBK ");
else
qy= "未知 ";

if   (job!=null)  
job   =   new   String(job.getBytes( "ISO-8859-1 "),   "GBK ");
else
job= "未知 ";

if   (bm!=null)  
bm   =   new   String(bm.getBytes( "ISO-8859-1 "),   "GBK ");
else
bm= "未知 ";

if   (username!=null)  
username   =   new   String(username.getBytes( "ISO-8859-1 "),   "GBK ");
else
username= "未知 ";

if   ( "1 ".equals(type)){}else{type= "0 ";}

// 检查帐号是否重复
String   clickSql= "Select   userid   From   Manages   Where   userid=? ";
PreparedStatement   perstmt=conn.prepareStatement(clickSql);;
perstmt.setString(1,userid);
ResultSet   rs=perstmt.executeQuery();
if(rs.next()){
System.out.print( "对不起,帐号重复了! ");
}else{
//添加管理员信息
String   sql= "Insert   Into   Manages(userid,[password],qy,username,job,bm,type)   values(?,?,?,?,?,?,?) ";
perstmt=conn.prepareStatement(sql);

perstmt.setString(1,userid);
perstmt.setString(2,password);
perstmt.setString(3,qy);
perstmt.setString(4,username);
perstmt.setString(5,job);
perstmt.setString(6,bm);
perstmt.setString(7,type);
perstmt.executeUpdate();
System.out.print( "成功添加管理员信息! ");