如何将这段代码拆分为2个子方法

Question

public void demo()
{
if (action.equals("single"))
{
if (version!=null && version.length()>0)
{
try{
Integer.parseInt(version);
ver=version;
}catch(Exception e)
{
out.println(config.pagemessage("back", "", "<font color=\"red\">版本信息错误!请输入正确的版本!</font>", 5000));
return;
}
}
if (connection!=null && connection.length()>0)
{
try{
number=Integer.parseInt(connection);
}catch(Exception e)
{
out.println(config.pagemessage("back", "", "<font color=\"red\">最小连接数错误!请输入正确的连接数!</font>", 5000));
return;
}
}
}
}public void demo()
{
checkVersion();
checkConnection();
}

Answer 1

if 里的二个if可以方不过这二个if里操作这没简单是不是没这必要

Answer 2

嗯 可以看成就一个try....catch 
关键是如何 return

Answer 3

checkvarsion:if (action.equals("single")&&version!=null && version.length()>0)
        {
            try{
                Integer.parseInt(version);
                ver=version;
            }catch(Exception e)
            {
                out.println(config.pagemessage("back", "", "<font color=\"red\">版本信息错误!请输入正确的版本!</font>", 5000));
                return;
            }
        }checkConnection:
if (action.equals("single") && connection!=null && connection.length()>0)
        {
            try{
                number=Integer.parseInt(connection);
            }catch(Exception e)
            {
                out.println(config.pagemessage("back", "", "<font color=\"red\">最小连接数错误!请输入正确的连接数!</font>", 5000));
                return;
            }
        }

Answer 4

public void demo()
{
if (action.equals("single"))
    {
     try{
       a();
       b();
     }catch(Exception e)
            {
                out.println(config.pagemessage("back", e.getMessage(),5000));
                return;
            }
     }
}
private int a(String version){
if (version!=null && version.length()>0)
        {
            try{
               ver= Integer.parseInt(version);
            }catch(Exception e)
            {
throw new NullPointerException("<font color=\"red\">版本信息错误!请输入正确的版本!</font>");
            }
        }
return ver;}private int b(String connection)throws Exception{
         if (connection!=null && connection.length()>0)
        {
            try{
                number=Integer.parseInt(connection);
            }catch(Exception e)
            {
                throw new NullPointerException("<font color=\"red\">最小连接数错误!请输入正确的连接数!</font>");
                            }
        }
return number;
}

Answer 5

throw new NullPointerException 这改成Exception 写错了
a没throws Exception

Answer 6

try{
       a();
       b();
     }catch(Exception e)
            {
                out.println(config.pagemessage("back", e.getMessage(),5000));
                return;
            }没传值的...