IntSummaryStatistics (Java SE 10 & JDK 10 ) (original) (raw)

java.lang.Object
- java.util.IntSummaryStatistics
All Implemented Interfaces:
[IntConsumer](../../java/util/function/IntConsumer.html "interface in java.util.function")

public class IntSummaryStatistics
extends Object
implements IntConsumer
A state object for collecting statistics such as count, min, max, sum, and average.
This class is designed to work with (though does not require)streams. For example, you can compute summary statistics on a stream of ints with:
IntSummaryStatistics stats = intStream.collect(IntSummaryStatistics::new, IntSummaryStatistics::accept, IntSummaryStatistics::combine);
IntSummaryStatistics can be used as areduction target for a stream. For example:
IntSummaryStatistics stats = people.stream() .collect(Collectors.summarizingInt(Person::getDependents));
This computes, in a single pass, the count of people, as well as the minimum, maximum, sum, and average of their number of dependents.
Implementation Note:
This implementation is not thread safe. However, it is safe to useCollectors.summarizingInt() on a parallel stream, because the parallel implementation of Stream.collect() provides the necessary partitioning, isolation, and merging of results for safe and efficient parallel execution.
This implementation does not check for overflow of the sum.
Since:
1.8

Constructor Summary

Constructors

Constructor	Description
IntSummaryStatistics()	Constructs an empty instance with zero count, zero sum,Integer.MAX_VALUE min, Integer.MIN_VALUE max and zero average.
IntSummaryStatistics(long count, int min, int max, long sum)	Constructs a non-empty instance with the specified count,min, max, and sum.

Method Summary

All Methods Instance Methods Concrete Methods

Modifier and Type	Method	Description
void	accept(int value)	Records a new value into the summary information
void	combine(IntSummaryStatistics other)	Combines the state of another IntSummaryStatistics into this one.
double	getAverage()	Returns the arithmetic mean of values recorded, or zero if no values have been recorded.
long	getCount()	Returns the count of values recorded.
int	getMax()	Returns the maximum value recorded, or Integer.MIN_VALUE if no values have been recorded.
int	getMin()	Returns the minimum value recorded, or Integer.MAX_VALUE if no values have been recorded.
long	getSum()	Returns the sum of values recorded, or zero if no values have been recorded.
String	toString()	Returns a non-empty string representation of this object suitable for debugging.

   * ### Methods declared in interface java.util.function.[IntConsumer](../../java/util/function/IntConsumer.html "interface in java.util.function")  
   `[andThen](../../java/util/function/IntConsumer.html#andThen%28java.util.function.IntConsumer%29)`  
   * ### Methods declared in class java.lang.[Object](../../java/lang/Object.html "class in java.lang")  
   `[clone](../../java/lang/Object.html#clone%28%29), [equals](../../java/lang/Object.html#equals%28java.lang.Object%29), [finalize](../../java/lang/Object.html#finalize%28%29), [getClass](../../java/lang/Object.html#getClass%28%29), [hashCode](../../java/lang/Object.html#hashCode%28%29), [notify](../../java/lang/Object.html#notify%28%29), [notifyAll](../../java/lang/Object.html#notifyAll%28%29), [wait](../../java/lang/Object.html#wait%28%29), [wait](../../java/lang/Object.html#wait%28long%29), [wait](../../java/lang/Object.html#wait%28long,int%29)`

Constructor Detail

 * #### IntSummaryStatistics  
 public IntSummaryStatistics()  
 Constructs an empty instance with zero count, zero sum,`Integer.MAX_VALUE` min, `Integer.MIN_VALUE` max and zero average.  
 * #### IntSummaryStatistics  
 public IntSummaryStatistics(long count,  
                             int min,  
                             int max,  
                             long sum)  
                      throws [IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")  
 Constructs a non-empty instance with the specified `count`,`min`, `max`, and `sum`.  
 If `count` is zero then the remaining arguments are ignored and an empty instance is constructed.  
 If the arguments are inconsistent then an `IllegalArgumentException` is thrown. The necessary consistent argument conditions are:  
          * `count >= 0`  
          * `min <= max`  
 API Note:  
 The enforcement of argument correctness means that the retrieved set of recorded values obtained from a `IntSummaryStatistics` source instance may not be a legal set of arguments for this constructor due to arithmetic overflow of the source's recorded count of values. The consistent argument conditions are not sufficient to prevent the creation of an internally inconsistent instance. An example of such a state would be an instance with: `count` \= 2, `min` \= 1,`max` \= 2, and `sum` \= 0.  
 Parameters:  
 `count` \- the count of values  
 `min` \- the minimum value  
 `max` \- the maximum value  
 `sum` \- the sum of all values  
 Throws:  
 `[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if the arguments are inconsistent  
 Since:  
 10

Method Detail

* #### accept  
public void accept(int value)  
Records a new value into the summary information  
Specified by:  
`[accept](../../java/util/function/IntConsumer.html#accept%28int%29)` in interface `[IntConsumer](../../java/util/function/IntConsumer.html "interface in java.util.function")`  
Parameters:  
`value` \- the input value  
* #### combine  
public void combine([IntSummaryStatistics](../../java/util/IntSummaryStatistics.html "class in java.util") other)  
Combines the state of another `IntSummaryStatistics` into this one.  
Parameters:  
`other` \- another `IntSummaryStatistics`  
Throws:  
`[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if `other` is null  
* #### getCount  
public final long getCount()  
Returns the count of values recorded.  
Returns:  
the count of values  
* #### getSum  
public final long getSum()  
Returns the sum of values recorded, or zero if no values have been recorded.  
Returns:  
the sum of values, or zero if none  
* #### getMin  
public final int getMin()  
Returns the minimum value recorded, or `Integer.MAX_VALUE` if no values have been recorded.  
Returns:  
the minimum value, or `Integer.MAX_VALUE` if none  
* #### getMax  
public final int getMax()  
Returns the maximum value recorded, or `Integer.MIN_VALUE` if no values have been recorded.  
Returns:  
the maximum value, or `Integer.MIN_VALUE` if none  
* #### getAverage  
public final double getAverage()  
Returns the arithmetic mean of values recorded, or zero if no values have been recorded.  
Returns:  
the arithmetic mean of values, or zero if none  
* #### toString  
public [String](../../java/lang/String.html "class in java.lang") toString()  
Returns a non-empty string representation of this object suitable for debugging. The exact presentation format is unspecified and may vary between implementations and versions.  
Overrides:  
`[toString](../../java/lang/Object.html#toString%28%29)` in class `[Object](../../java/lang/Object.html "class in java.lang")`  
Returns:  
a string representation of the object.

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IntSummaryStatistics (Java SE 10 & JDK 10 ) (original) (raw)

Constructor Summary

Method Summary

Constructor Detail

Method Detail