Class IteratorTool
- java.lang.Object
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- org.apache.velocity.tools.generic.IteratorTool
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- All Implemented Interfaces:
java.util.Iterator
@DefaultKey("mill") @Deprecated public class IteratorTool extends java.lang.Object implements java.util.Iterator
Deprecated.UseLoopTool
insteadA 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.
- Version:
- $Id: IteratorTool.java 598471 2007-11-27 00:26:10Z nbubna $
- Author:
- Denis Bredelet
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Field Summary
Fields Modifier and Type Field Description private boolean
cachedNext
Deprecated.private java.util.Iterator
iterator
Deprecated.protected java.lang.Object
next
Deprecated.private boolean
wantMore
Deprecated.private java.lang.Object
wrapped
Deprecated.
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Constructor Summary
Constructors Constructor Description IteratorTool()
Deprecated.Create a IteratorTool instance to use as tool.IteratorTool(java.lang.Object wrapped)
Deprecated.Create a IteratorTool instance to use in #foreach.
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Method Summary
All Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description boolean
hasMore()
Deprecated.Returns true if there are more elements in the wrapped list.boolean
hasNext()
Deprecated.Returns true if there are more elements in the list and more() was called.private void
internalWrap(java.lang.Object wrapped)
Deprecated.Wraps a list with the tool.java.lang.Object
more()
Deprecated.Asks for the next element in the list.java.lang.Object
next()
Deprecated.Gets the next object in the list.void
remove()
Deprecated.Removes the current element from the list.void
reset()
Deprecated.Resets the wrapper so that it starts over at the beginning of the list.void
stop()
Deprecated.Puts a condition to break out of the loop.java.lang.String
toString()
Deprecated.Returns this object as a String.IteratorTool
wrap(java.lang.Object list)
Deprecated.Wraps a list with the tool.
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Constructor Detail
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IteratorTool
public IteratorTool()
Deprecated.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.
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IteratorTool
public IteratorTool(java.lang.Object wrapped)
Deprecated.Create a IteratorTool instance to use in #foreach.- Parameters:
wrapped
- The list to wrap.
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Method Detail
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wrap
public IteratorTool wrap(java.lang.Object list)
Deprecated.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.- Parameters:
list
- The list to wrap.- Returns:
- A new wrapper if this object is used as a tool, or itself if it is a wrapper.
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internalWrap
private void internalWrap(java.lang.Object wrapped)
Deprecated.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.- Parameters:
wrapped
- The list to wrap.
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reset
public void reset()
Deprecated.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
public java.lang.Object next()
Deprecated.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().
- Specified by:
next
in interfacejava.util.Iterator
- Returns:
- The next item in the list.
- Throws:
NoSuchElementException
- if there are no more elements in the list.
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hasNext
public boolean hasNext()
Deprecated.Returns true if there are more elements in the list and more() was called.
This code always return false:tool.hasNext()? tool.hasNext(): false;
- Specified by:
hasNext
in interfacejava.util.Iterator
- Returns:
- true if there are more elements, and either more() or hasNext() was called since last call.
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remove
public void remove() throws java.lang.UnsupportedOperationException
Deprecated.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().- Specified by:
remove
in interfacejava.util.Iterator
- Throws:
java.lang.UnsupportedOperationException
- if the wrapped list iterator doesn't support this operation.
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more
public java.lang.Object more()
Deprecated.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.- Returns:
- The next element in the list, or null if there are no more elements.
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hasMore
public boolean hasMore()
Deprecated.Returns true if there are more elements in the wrapped list.
If this object doesn't wrap a list, the method always returns false.- Returns:
- true if there are more elements in the list.
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stop
public void stop()
Deprecated.Puts a condition to break out of the loop. The #foreach loop will terminate after this iteration, unless more() is called after stop().
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toString
public java.lang.String toString()
Deprecated.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.- Overrides:
toString
in classjava.lang.Object
- Returns:
- A string representation of this object.
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