当我试图从selectManyCheckbox检索选中的项目时，while循环到无穷大

Question

我想从复选框中恢复选中的项目列表，当我迭代列表以检索选中的项目时，指令while循环到无限的问题这是我的代码:

JSF:

  <h:selectManyCheckbox value="#{TestAjax.selectedItemscheckbox}">
<f:selectItem itemValue="priority.pname" itemLabel="By priority" />
<f:selectItem itemValue="project.pname" itemLabel="By project" />    
</h:selectManyCheckbox>

代码:

public Class TestAjax {
private ArrayList<String> selectedItemscheckbox;  //list of checkbox used for grouping

public ArrayList<String> getSelectedItemscheckbox() {
    return selectedItemscheckbox;
}
public void setSelectedItemscheckbox(ArrayList<String> selectedItemscheckbox) {
    this.selectedItemscheckbox = selectedItemscheckbox;
}

public void CreateQueryNumber()
{ 
 Iterator it= selectedItemscheckbox.iterator();
 System.out.println("checkeddddddddddd"+selectedItemscheckbox);
 while(it.hasNext())  ===>loop to the  infinity
 {
   System.out.println("one"+ it.toString());
 select ="select count(jiraissue.id) as nb";
 from ="jiraissue j ,priority pr ,project proj";
 where="j.project=proj.id";
 jointure="j.priority =pr.id";
 groupBy="group by "+it.toString();
}

}

Answer 1

您没有对它进行任何调用。要解决这个问题，您可以在循环末尾添加it.next():

  while(it.hasNext()){
       .... bla bla bla ....
       it.next();
  }

或者像

  Object obj;
  while((obj = it.next()) != null){
       .... bla bla bla ....
  }

Answer 2

调用it.next()不是为了将迭代器跳转到下一个值。

while(it.hasNext())
{
  String i_str = it.next().toString();
  System.out.println( "one"+ i_str );
  select ="select count(jiraissue.id) as nb";
  from ="jiraissue j ,priority pr ,project proj";
  where="j.project=proj.id";
  jointure="j.priority =pr.id";
  groupBy="group by "+i_str;
}

Answer 3

您还在使用Java 1.4或更早的版本吗?你已经是1.5或更高版本了，对吧?使用增强的for循环。

for (String selectedItem : selectedItemscheckbox) {
    System.out.println(selectedItem);
    // ...
}