分析字符串的问题? 求救!!!!!!!!!

Question

你判断一下,if为null就置为""就是了

Answer 1

不知道是不是我写错了,你帮我看一下.谢谢!!
wdate=t.nextToken();
IF(wdate=="")
{
list.addElement(" ");}
else
{
list.addElement(wdate);
}

Answer 2

写错了
应该是
if (wdate!=null && !wdate.equals(""))

Answer 3

还是不对!我把整个程序给你看!<%!
  String s,a;
  File f;
  FileReader files;
  BufferedReader in;  Users oUsers;
  String UserNo,UserName;
  String Family,vdate,comname,bname,hname,yname,money,vmoney,zmoney,wmoney,wdate,number;%>
<%   double m=0,n=0;
   Vector list=new Vector();
   Vector list1=new Vector();
   try
   {
     f=new File("D:/..","../header.csv");
     files=new FileReader(f);
     in=new BufferedReader(files);
while((s=in.readLine())!=null)
{    StringTokenizer t=new StringTokenizer(s,",");
           
    bname=t.nextToken();   
list.addElement(bname);

Family=t.nextToken();   
list.addElement(Family);

        vdate=t.nextToken();   
list.addElement(vdate);
    StringTokenizer t1=new StringTokenizer(vdate,"/   -");
     while(t1.hasMoreTokens())
    {
            a=t1.nextToken();
    list1.addElement(a);
   
    }
            
comname=t.nextToken(); 
list.addElement(comname);
  
    hname=t.nextToken();   
list.addElement(hname);
    
yname=t.nextToken();   
list.addElement(yname);
    
money=t.nextToken();   
list.addElement(money);
           
    vmoney=t.nextToken();  
list.addElement(vmoney);
   
    zmoney=t.nextToken();     
list.addElement(zmoney);

number=t.nextToken();
list.addElement(number);

wmoney=t.nextToken();
list.addElement(wmoney);
 
wdate=t.nextToken();
list.addElement(wdate);
wdate=t.nextToken();
            if (wdate!=null && !wdate.equals(""))            {
             list.addElement(" ");            }
           else
            {
              list.addElement(wdate);
            } //out.print(vdate);
        }
    }   catch(FileNotFoundException e){}
   catch(IOException e){}
   session.putValue("list",list);
   session.putValue("list1",list1);
   //out.print(list);
   response.sendRedirect("bb.jsp");
%>

Answer 4

这样试试：
if(wdate==null||wadate.equals(""))
{
list.addElement(" ");}
else
{
list.addElement(wdate);
}

Answer 5

纠错：
if(wdate==null||wadate.equals(""))//wadate应为wdate