类 IteratorTool
- 所有已实现的接口:
Iterator
A convenience tool to use with #foreach loops. It wraps a list to let the designer specify a condition to terminate the loop, and reuse the same list in different loops.
Example of use:
Java ---- context.put("mill", new IteratorTool()); VTL --- #set ($list = [1, 2, 3, 5, 8, 13]) #set ($numbers = $mill.wrap($list)) #foreach ($item in $numbers) #if ($item < 8) $numbers.more()#end #end $numbers.more() Output ------ 1 2 3 5 8 Example tools.xml config (if you want to use this with VelocityView): <tools> <toolbox scope="request"> <tool class="org.apache.velocity.tools.generic.IteratorTool"/> </toolbox> </tools>
Warning: It is not recommended to use hasNext() with this tool as it is used to control the #foreach. Use hasMore() instead.
- 版本:
- $Id: IteratorTool.java 598471 2007-11-27 00:26:10Z nbubna $
- 作者:
- Denis Bredelet
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字段概要
字段 -
构造器概要
构造器构造器说明已过时。Create a IteratorTool instance to use as tool.IteratorTool
(Object wrapped) 已过时。Create a IteratorTool instance to use in #foreach. -
方法概要
修饰符和类型方法说明boolean
hasMore()
已过时。Returns true if there are more elements in the wrapped list.boolean
hasNext()
已过时。Returns true if there are more elements in the list and more() was called.private void
internalWrap
(Object wrapped) 已过时。Wraps a list with the tool.more()
已过时。Asks for the next element in the list.next()
已过时。Gets the next object in the list.void
remove()
已过时。Removes the current element from the list.void
reset()
已过时。Resets the wrapper so that it starts over at the beginning of the list.void
stop()
已过时。Puts a condition to break out of the loop.toString()
已过时。Returns this object as a String.已过时。Wraps a list with the tool.从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
从接口继承的方法 java.util.Iterator
forEachRemaining
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字段详细资料
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wrapped
已过时。 -
iterator
已过时。 -
wantMore
private boolean wantMore已过时。 -
cachedNext
private boolean cachedNext已过时。 -
next
已过时。
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-
构造器详细资料
-
IteratorTool
public IteratorTool()已过时。Create a IteratorTool instance to use as tool. When it is created this way, the tool returns a new instance each time wrap() is called. This is useful when you want to allow the designers to create instances. -
IteratorTool
已过时。Create a IteratorTool instance to use in #foreach.- 参数:
wrapped
- The list to wrap.
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方法详细资料
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wrap
已过时。Wraps a list with the tool.
The list can be an array, a Collection, a Map, an Iterator or an Enumeration.
If the list is a Map, the tool iterates over the values.
If the list is an Iterator or an Enumeration, the tool can be used only once.- 参数:
list
- The list to wrap.- 返回:
- A new wrapper if this object is used as a tool, or itself if it is a wrapper.
-
internalWrap
已过时。Wraps a list with the tool. This object can therefore be used instead of the list itself in a #foreach. The list can be an array, a Collection, a Map, an Iterator or an Enumeration.
- If the list is a Map, the tool iterates over the values.
- If the list is an Iterator or an Enumeration, the tool can be used only once.- 参数:
wrapped
- The list to wrap.
-
reset
public void reset()已过时。Resets the wrapper so that it starts over at the beginning of the list.
Note to programmers: This method has no effect if the wrapped object is an enumeration or an iterator.
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next
已过时。Gets the next object in the list. This method is called by #foreach to define $item in:
#foreach( $item in $list )
This method is not intended for template designers, but they can use them if they want to read the value of the next item without doing more().
-
hasNext
public boolean hasNext()已过时。Returns true if there are more elements in the list and more() was called.
This code always return false:tool.hasNext()? tool.hasNext(): false;
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remove
已过时。Removes the current element from the list. The current element is defined as the last element that was read from the list, either with next() or with more().- 指定者:
remove
在接口中Iterator
- 抛出:
UnsupportedOperationException
- if the wrapped list iterator doesn't support this operation.
-
more
已过时。Asks for the next element in the list. This method is to be used by the template designer in #foreach loops.
If this method is called in the body of #foreach, the loop continues as long as there are elements in the list.
If this method is not called the loop terminates after the current iteration.- 返回:
- The next element in the list, or null if there are no more elements.
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hasMore
public boolean hasMore()已过时。Returns true if there are more elements in the wrapped list.
If this object doesn't wrap a list, the method always returns false.- 返回:
- true if there are more elements in the list.
-
stop
public void stop()已过时。Puts a condition to break out of the loop. The #foreach loop will terminate after this iteration, unless more() is called after stop(). -
toString
已过时。Returns this object as a String.
If this object is used as a tool, it just gives the class name.
Otherwise it appends the wrapped list to the class name.
-
LoopTool
instead