Java开发网 - Collection ret=new ArrayList();谁能帮帮我如何理解这个码段

Topic: Collection ret=new ArrayList();谁能帮帮我如何理解这个码段

1.Collection ret=new ArrayList();谁能帮帮我如何理解这个码段

Posted by: sshgwyx
Posted on: 2004-09-13 10:56

public Collection getMessage()throws Exception
{
Collection ret=new ArrayList();
try
{
Statement stm=con.createStatement();
ResultSet result=stm.executeQuery("select count Start

from message");
　int message_count=0;
　if(result.next())
　{
　　　message_count=result.getInt(1);
    result.close();
　}
　if(message_count>0)
　{
　　result=stm.executeQuery("select * from message order by time desc");
  while(result.next())
  {
    String title=result.getString("title");
    MessageVO message=new MessageVO();
    message.setName(name);
    ret.add(message);//？？如何理解

  }
  result.close();
  stm.close();
  }
  con.close();
　　　　　}
  catch(Exception e)
  {
  e.printStackTrace();
  throw e;
  }
  return ret;//？？如何理解
}

2.Re:Collection ret=new ArrayList();谁能帮帮我如何理解这个码段 [Re: sshgwyx]

Copy to clipboard

Posted by: zzgf16
Posted on: 2004-09-13 13:19

public Collection getMessage()throws Exception
{
Collection ret=new ArrayList();
try
{
Statement stm=con.createStatement();
ResultSet result=stm.executeQuery("select count Start

from message");
　int message_count=0;
　if(result.next())
　{
　　　message_count=result.getInt(1);//返回message表里的所有记录数
result.close();
　}
　if(message_count>0)
　{
　　result=stm.executeQuery("select * from message order by time desc");//如果message表里有记录按时间time的降序排列
while(result.next())
{
String title=result.getString("title");//String title定义错了，应该是name
MessageVO message=new MessageVO();
message.setName(name);
ret.add(message);//？？如何理解：ret是ARRAYLIST型集合，它加入了MessageVO 的对象

}
result.close();
stm.close();
}
con.close();
　　　　　}
catch(Exception e)
{
e.printStackTrace();
throw e;
}
return ret;//？？如何理解//返回ret这个集合，集合里包含着message表里title字段的名字的多个MessageVO对象
}
请大家批评指正，谢谢！！

3.Re:Collection ret=new ArrayList();谁能帮帮我如何理解这个码段 [Re: sshgwyx]	Copy to clipboard
Posted by: sshgwyx Posted on: 2004-09-13 14:42 谢谢了！快乐同您常在