Package org.apache.commons.math3.util
Class IntegerSequence.Incrementor
- java.lang.Object
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- org.apache.commons.math3.util.IntegerSequence.Incrementor
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- All Implemented Interfaces:
java.util.Iterator<java.lang.Integer>
- Enclosing class:
- IntegerSequence
public static class IntegerSequence.Incrementor extends java.lang.Object implements java.util.Iterator<java.lang.Integer>
Utility that increments a counter until a maximum is reached, at which point, the instance will by default throw aMaxCountExceededException
. However, the user is able to override this behaviour by defining a customcallback
, in order to e.g. select which exception must be thrown.
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Nested Class Summary
Nested Classes Modifier and Type Class Description static interface
IntegerSequence.Incrementor.MaxCountExceededCallback
Defines a method to be called at counter exhaustion.
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Field Summary
Fields Modifier and Type Field Description private static IntegerSequence.Incrementor.MaxCountExceededCallback
CALLBACK
Default callback.private int
count
Current count.private int
increment
Increment.private int
init
Initial value the counter.private IntegerSequence.Incrementor.MaxCountExceededCallback
maxCountCallback
Function called at counter exhaustion.private int
maximalCount
Upper limit for the counter.
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Constructor Summary
Constructors Modifier Constructor Description private
Incrementor(int start, int max, int step, IntegerSequence.Incrementor.MaxCountExceededCallback cb)
Creates an incrementor.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
canIncrement()
Checks whether incrementing the counternTimes
is allowed.boolean
canIncrement(int nTimes)
Checks whether incrementing the counter several times is allowed.static IntegerSequence.Incrementor
create()
Factory method that creates a default instance.int
getCount()
Gets the current count.int
getMaximalCount()
Gets the upper limit of the counter.boolean
hasNext()
void
increment()
Adds the increment value to the current iteration count.void
increment(int nTimes)
Performs multiple increments.java.lang.Integer
next()
void
remove()
Not applicable.IntegerSequence.Incrementor
withCallback(IntegerSequence.Incrementor.MaxCountExceededCallback cb)
Creates a new instance with a given callback.IntegerSequence.Incrementor
withIncrement(int step)
Creates a new instance with a given increment.IntegerSequence.Incrementor
withMaximalCount(int max)
Creates a new instance with a given maximal count.IntegerSequence.Incrementor
withStart(int start)
Creates a new instance with a given initial value.
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Field Detail
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CALLBACK
private static final IntegerSequence.Incrementor.MaxCountExceededCallback CALLBACK
Default callback.
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init
private final int init
Initial value the counter.
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maximalCount
private final int maximalCount
Upper limit for the counter.
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increment
private final int increment
Increment.
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maxCountCallback
private final IntegerSequence.Incrementor.MaxCountExceededCallback maxCountCallback
Function called at counter exhaustion.
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count
private int count
Current count.
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Constructor Detail
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Incrementor
private Incrementor(int start, int max, int step, IntegerSequence.Incrementor.MaxCountExceededCallback cb) throws NullArgumentException
Creates an incrementor. The counter will be exhausted either whenmax
is reached or whennTimes
increments have been performed.- Parameters:
start
- Initial value.max
- Maximal count.step
- Increment.cb
- Function to be called when the maximal count has been reached.- Throws:
NullArgumentException
- ifcb
isnull
.
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Method Detail
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create
public static IntegerSequence.Incrementor create()
Factory method that creates a default instance. The initial and maximal values are set to 0. For the new instance to be useful, the maximal count must be set by callingwithMaximalCount
.- Returns:
- an new instance.
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withStart
public IntegerSequence.Incrementor withStart(int start)
Creates a new instance with a given initial value. The counter is reset to the initial value.- Parameters:
start
- Initial value of the counter.- Returns:
- a new instance.
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withMaximalCount
public IntegerSequence.Incrementor withMaximalCount(int max)
Creates a new instance with a given maximal count. The counter is reset to the initial value.- Parameters:
max
- Maximal count.- Returns:
- a new instance.
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withIncrement
public IntegerSequence.Incrementor withIncrement(int step)
Creates a new instance with a given increment. The counter is reset to the initial value.- Parameters:
step
- Increment.- Returns:
- a new instance.
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withCallback
public IntegerSequence.Incrementor withCallback(IntegerSequence.Incrementor.MaxCountExceededCallback cb)
Creates a new instance with a given callback. The counter is reset to the initial value.- Parameters:
cb
- Callback to be called at counter exhaustion.- Returns:
- a new instance.
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getMaximalCount
public int getMaximalCount()
Gets the upper limit of the counter.- Returns:
- the counter upper limit.
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getCount
public int getCount()
Gets the current count.- Returns:
- the current count.
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canIncrement
public boolean canIncrement()
Checks whether incrementing the counternTimes
is allowed.- Returns:
false
if callingincrement()
will trigger aMaxCountExceededException
,true
otherwise.
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canIncrement
public boolean canIncrement(int nTimes)
Checks whether incrementing the counter several times is allowed.- Parameters:
nTimes
- Number of increments.- Returns:
false
if callingincrement(nTimes)
would call thecallback
true
otherwise.
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increment
public void increment(int nTimes) throws MaxCountExceededException
Performs multiple increments.- Parameters:
nTimes
- Number of increments.- Throws:
MaxCountExceededException
- at counter exhaustion.NotStrictlyPositiveException
- ifnTimes <= 0
.- See Also:
increment()
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increment
public void increment() throws MaxCountExceededException
Adds the increment value to the current iteration count. At counter exhaustion, this method will call thetrigger
method of the callback object passed to thewithCallback(MaxCountExceededCallback)
method. If not explicitly set, a default callback is used that will throw aMaxCountExceededException
.- Throws:
MaxCountExceededException
- at counter exhaustion, unless a customcallback
has been set.- See Also:
increment(int)
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hasNext
public boolean hasNext()
- Specified by:
hasNext
in interfacejava.util.Iterator<java.lang.Integer>
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next
public java.lang.Integer next()
- Specified by:
next
in interfacejava.util.Iterator<java.lang.Integer>
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remove
public void remove()
Not applicable.- Specified by:
remove
in interfacejava.util.Iterator<java.lang.Integer>
- Throws:
MathUnsupportedOperationException
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