这个bean写的对吗?

这样当然不好，你把连接搞进来。
如果换个环境，你所有的bean都得改，累得不行。

不是很好，首先数据库最好作为一个单独的bean，在以后应用中可以设为session变量，其他bean可以接受它传入的参数，这样数据库的压力也不是特别大。变量全是private太绝对了，如果要好的习惯的话，可以加一个error的显示的变量public

这是我的:
//连接数据库
package com.data;
import java.sql.*;
import java.util.*;
public class DBConnect
{
private Connection con=null;
private ResultSet rs=null;
private Statement stmt=null;
//private String strDRV="sun.jdbc.odbc.JdbcOdbcDriver";
private String strDRV="sun.jdbc.odbc.JdbcOdbcDriver";
private String strURL="jdbc:odbc:mysite"; public DBConnect(){
try{
    Class.forName(strDRV);
        con=DriverManager.getConnection(strURL,"","");      }catch(Exception e){
    System.out.print("Error is:"+e);
    }
   }
public Connection getConn()
{
return con;
}
public ResultSet executeQuery(String sql)
{
try{
stmt=con.createStatement();
rs=stmt.executeQuery(sql);
}catch(Exception e){
System.out.print("Error in query:"+e);
}
return rs;
}
public int executeUpdate(String sql)
{
int flag=0;
try{
stmt=con.createStatement();
flag=stmt.executeUpdate(sql);
}catch(Exception e){
}
return flag;
}
public void destroy()
{
try{
stmt.close();
}catch(Exception e){
}
try{
con.close();
}catch(Exception e){
}
}
}
//操作数据库
import java.sql.*;
public class  KeyDB
{
private Connection con=null;
private static final String sql_insert="insert into test(id,content) values(?,?)";
private static final String sql_query="select * from test";
private static final String sql_queryid="select * from test where id=?";
private String id=null;
private String content=null;
private KeyModel km=null;
private String go=null;
public String toString()
{
return go;
}
public int executeInsert(Connection con,KeyModel km)
{
this.con=con;
this.km=km;
setKm();
return executeInsert();
}
public int executeInsert()
{
int i=0;
try{
byte bs[]=new xiao().encrypt(content);
PreparedStatement pstm=con.prepareStatement(sql_insert);
pstm.setString(1,id);
pstm.setBytes(2,bs);
i=pstm.executeUpdate();
go=new xiao().uncrypt(bs);
}catch(Exception e)
{
i=-1;
}
return i;
}
public KeyModel executeQueryId(Connection con,String id)
{
this.con=con;
this.id=id;
return executeQueryId();
}
public KeyModel executeQueryId()
{
KeyModel kml=new KeyModel();
try{
PreparedStatement pstm=con.prepareStatement(sql_queryid);
pstm.setString(1,id);
ResultSet rs=pstm.executeQuery();
if(rs.next())
{
kml.setId(id);
byte bl[]=rs.getBytes("content");
String str=new xiao().uncrypt(bl);
kml.setContent(str);
}
}catch(Exception e)
{
System.out.print("err in KeyModel executeQueryId()!");
}
return kml;
}
public KeyVector executeQuery(Connection con)
{
this.con=con;
return executeQuery();
}
public KeyVector executeQuery()
{
KeyVector kv=new KeyVector();
try{
PreparedStatement pstm=con.prepareStatement(sql_query);
ResultSet rs=pstm.executeQuery();
while(rs.next())
{
byte bl[]=rs.getBytes("content");
id=rs.getString("id");
String str=new xiao().uncrypt(bl);
KeyModel km=new KeyModel(id,str);
kv.add(km);
}
}catch(SQLException e)
{
System.out.println("err in KeyDB executeQuery()!");
}
return kv;
}
private void setKm()
{
this.id=km.getId();
this.content=km.getContent();
}
}
//数据模型
public class KeyModel
{
private String id=null;
private String content=null;
public KeyModel(){};
public KeyModel(String id,String content)
{
this.id=id;
this.content=content;
}
public void setId(String id)
{
this.id=id;
}
public void setContent(String content)
{
this.content=content;
}
public String getId()
{
return id;
}
public String getContent()
{
return content;
}
}
//多个数据的
import java.util.Vector;
public class KeyVector
{
Vector vt=null;
public KeyVector()
{
vt=new Vector();
}
public void add(KeyModel km)
{
vt.add(km);
}
public KeyModel get(int index)
{
return (KeyModel)vt.get(index);
}
public int size()
{
return vt.size();
}
}
仅供参考!

sql语句和操作数据库的放在一起.

To xiaofenguser(风雨):
请教你的这个数据模型public class KeyModel
有什么意义和作用么？？谢谢

调试易

这个bean写的对吗?

解决方案 »