8010953: Add primitive summary statistics utils
Reviewed-by: mduigou, dholmes, chegar, darcy
This commit is contained in:
parent
aefbf5bd89
commit
25b15c7837
187
jdk/src/share/classes/java/util/DoubleSummaryStatistics.java
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187
jdk/src/share/classes/java/util/DoubleSummaryStatistics.java
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@ -0,0 +1,187 @@
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/*
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* Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
|
||||
* published by the Free Software Foundation. Oracle designates this
|
||||
* particular file as subject to the "Classpath" exception as provided
|
||||
* by Oracle in the LICENSE file that accompanied this code.
|
||||
*
|
||||
* This code is distributed in the hope that it will be useful, but WITHOUT
|
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
||||
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
||||
* version 2 for more details (a copy is included in the LICENSE file that
|
||||
* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
|
||||
* 2 along with this work; if not, write to the Free Software Foundation,
|
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package java.util;
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import java.util.function.DoubleConsumer;
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/**
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* A state object for collecting statistics such as count, min, max, sum, and
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* average.
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*
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* <p>This class is designed to work with (though does not require)
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* {@linkplain java.util.stream streams}. For example, you can compute
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* summary statistics on a stream of doubles with:
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* <pre> {@code
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* DoubleSummaryStatistics stats = doubleStream.collect(DoubleSummaryStatistics::new,
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* DoubleSummaryStatistics::accept,
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* DoubleSummaryStatistics::combine);
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* }</pre>
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*
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* <p>{@code DoubleSummaryStatistics} can be used as a
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* {@linkplain java.util.stream.Stream#reduce(java.util.function.BinaryOperator) reduction}
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* target for a {@linkplain java.util.stream.Stream stream}. For example:
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*
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* <pre> {@code
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* DoubleSummaryStatistics stats = people.stream()
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* .collect(Collectors.toDoubleSummaryStatistics(Person::getWeight));
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*}</pre>
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*
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* This computes, in a single pass, the count of people, as well as the minimum,
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* maximum, sum, and average of their weights.
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*
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* @implNote This implementation is not thread safe. However, it is safe to use
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* {@link java.util.stream.Collectors#toDoubleSummaryStatistics(java.util.function.ToDoubleFunction)
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* Collectors.toDoubleStatistics()} on a parallel stream, because the parallel
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* implementation of {@link java.util.stream.Stream#collect Stream.collect()}
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* provides the necessary partitioning, isolation, and merging of results for
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* safe and efficient parallel execution.
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* @since 1.8
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*/
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public class DoubleSummaryStatistics implements DoubleConsumer {
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private long count;
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private double sum;
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private double min = Double.POSITIVE_INFINITY;
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private double max = Double.NEGATIVE_INFINITY;
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/**
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* Construct an empty instance with zero count, zero sum,
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* {@code Double.POSITIVE_INFINITY} min, {@code Double.NEGATIVE_INFINITY}
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* max and zero average.
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*/
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public DoubleSummaryStatistics() { }
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/**
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* Records another value into the summary information.
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*
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* @param value the input value
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*/
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@Override
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public void accept(double value) {
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++count;
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sum += value;
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min = Math.min(min, value);
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max = Math.max(max, value);
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}
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/**
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* Combines the state of another {@code DoubleSummaryStatistics} into this
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* one.
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*
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* @param other another {@code DoubleSummaryStatistics}
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* @throws NullPointerException if {@code other} is null
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*/
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public void combine(DoubleSummaryStatistics other) {
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count += other.count;
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sum += other.sum;
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min = Math.min(min, other.min);
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max = Math.max(max, other.max);
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}
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/**
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* Return the count of values recorded.
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*
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* @return the count of values
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*/
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public final long getCount() {
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return count;
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}
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/**
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* Returns the sum of values recorded, or zero if no values have been
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* recorded. The sum returned can vary depending upon the order in which
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* values are recorded. This is due to accumulated rounding error in
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* addition of values of differing magnitudes. Values sorted by increasing
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* absolute magnitude tend to yield more accurate results. If any recorded
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* value is a {@code NaN} or the sum is at any point a {@code NaN} then the
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* sum will be {@code NaN}.
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*
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* @return the sum of values, or zero if none
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*/
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public final double getSum() {
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return sum;
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}
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/**
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* Returns the minimum recorded value, {@code Double.NaN} if any recorded
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* value was NaN or {@code Double.POSITIVE_INFINITY} if no values were
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* recorded. Unlike the numerical comparison operators, this method
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* considers negative zero to be strictly smaller than positive zero.
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*
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* @return the minimum recorded value, {@code Double.NaN} if any recorded
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* value was NaN or {@code Double.POSITIVE_INFINITY} if no values were
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* recorded
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*/
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public final double getMin() {
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return min;
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}
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/**
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* Returns the maximum recorded value, {@code Double.NaN} if any recorded
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* value was NaN or {@code Double.NEGATIVE_INFINITY} if no values were
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* recorded. Unlike the numerical comparison operators, this method
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* considers negative zero to be strictly smaller than positive zero.
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*
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* @return the maximum recorded value, {@code Double.NaN} if any recorded
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* value was NaN or {@code Double.NEGATIVE_INFINITY} if no values were
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* recorded
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*/
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public final double getMax() {
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return max;
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}
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/**
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* Returns the average of values recorded, or zero if no values have been
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* recorded. The average returned can vary depending upon the order in
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* which values are recorded. This is due to accumulated rounding error in
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* addition of values of differing magnitudes. Values sorted by increasing
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* absolute magnitude tend to yield more accurate results. If any recorded
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* value is a {@code NaN} or the sum is at any point a {@code NaN} then the
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* average will be {@code NaN}.
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*
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* @return the average of values, or zero if none
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*/
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public final double getAverage() {
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return getCount() > 0 ? getSum() / getCount() : 0.0d;
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}
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/**
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* {@inheritDoc}
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*
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* Returns a non-empty string representation of this object suitable for
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* debugging. The exact presentation format is unspecified and may vary
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* between implementations and versions.
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*/
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@Override
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public String toString() {
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return String.format(
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"%s{count=%d, sum=%f, min=%f, average=%f, max=%f}",
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this.getClass().getSimpleName(),
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getCount(),
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getSum(),
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getMin(),
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getAverage(),
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getMax());
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}
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}
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170
jdk/src/share/classes/java/util/IntSummaryStatistics.java
Normal file
170
jdk/src/share/classes/java/util/IntSummaryStatistics.java
Normal file
@ -0,0 +1,170 @@
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/*
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* Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
||||
*
|
||||
* This code is free software; you can redistribute it and/or modify it
|
||||
* under the terms of the GNU General Public License version 2 only, as
|
||||
* published by the Free Software Foundation. Oracle designates this
|
||||
* particular file as subject to the "Classpath" exception as provided
|
||||
* by Oracle in the LICENSE file that accompanied this code.
|
||||
*
|
||||
* This code is distributed in the hope that it will be useful, but WITHOUT
|
||||
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
||||
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
||||
* version 2 for more details (a copy is included in the LICENSE file that
|
||||
* accompanied this code).
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License version
|
||||
* 2 along with this work; if not, write to the Free Software Foundation,
|
||||
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
||||
*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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||||
* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package java.util;
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import java.util.function.IntConsumer;
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/**
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* A state object for collecting statistics such as count, min, max, sum, and
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* average.
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*
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* <p>This class is designed to work with (though does not require)
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* {@linkplain java.util.stream streams}. For example, you can compute
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* summary statistics on a stream of ints with:
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* <pre> {@code
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* IntSummaryStatistics stats = intStream.collect(IntSummaryStatistics::new,
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* IntSummaryStatistics::accept,
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* IntSummaryStatistics::combine);
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* }</pre>
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*
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* <p>{@code IntSummaryStatistics} can be used as a
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* {@linkplain java.util.stream.Stream#reduce(java.util.function.BinaryOperator) reduction}
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* target for a {@linkplain java.util.stream.Stream stream}. For example:
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*
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* <pre> {@code
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* IntSummaryStatistics stats = people.stream()
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* .collect(Collectors.toIntSummaryStatistics(Person::getDependents));
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*}</pre>
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*
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* This computes, in a single pass, the count of people, as well as the minimum,
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* maximum, sum, and average of their number of dependents.
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*
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* @implNote This implementation is not thread safe. However, it is safe to use
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* {@link java.util.stream.Collectors#toIntSummaryStatistics(java.util.function.ToIntFunction)
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* Collectors.toIntStatistics()} on a parallel stream, because the parallel
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* implementation of {@link java.util.stream.Stream#collect Stream.collect()}
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* provides the necessary partitioning, isolation, and merging of results for
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* safe and efficient parallel execution.
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*
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* <p>This implementation does not check for overflow of the sum.
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* @since 1.8
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*/
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public class IntSummaryStatistics implements IntConsumer {
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private long count;
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private long sum;
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private int min = Integer.MAX_VALUE;
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private int max = Integer.MIN_VALUE;
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/**
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* Construct an empty instance with zero count, zero sum,
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* {@code Integer.MAX_VALUE} min, {@code Integer.MIN_VALUE} max and zero
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* average.
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*/
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public IntSummaryStatistics() { }
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/**
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* Records a new value into the summary information
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*
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* @param value the input value
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*/
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@Override
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public void accept(int value) {
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++count;
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sum += value;
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min = Math.min(min, value);
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max = Math.max(max, value);
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}
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/**
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* Combines the state of another {@code IntSummaryStatistics} into this one.
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*
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* @param other another {@code IntSummaryStatistics}
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* @throws NullPointerException if {@code other} is null
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*/
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public void combine(IntSummaryStatistics other) {
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count += other.count;
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sum += other.sum;
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min = Math.min(min, other.min);
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max = Math.max(max, other.max);
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}
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/**
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* Returns the count of values recorded.
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*
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* @return the count of values
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*/
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public final long getCount() {
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return count;
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}
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/**
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* Returns the sum of values recorded, or zero if no values have been
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* recorded.
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*
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* @return the sum of values, or zero if none
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*/
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public final long getSum() {
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return sum;
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}
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/**
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* Returns the minimum value recorded, or {@code Integer.MAX_VALUE} if no
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* values have been recorded.
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*
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* @return the minimum value, or {@code Integer.MAX_VALUE} if none
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*/
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public final int getMin() {
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return min;
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}
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/**
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* Returns the maximum value recorded, or {@code Integer.MIN_VALUE} if no
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* values have been recorded.
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*
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* @return the maximum value, or {@code Integer.MIN_VALUE} if none
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*/
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public final int getMax() {
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return max;
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}
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/**
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* Returns the average of values recorded, or zero if no values have been
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* recorded.
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*
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* @return the average of values, or zero if none
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*/
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public final double getAverage() {
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return getCount() > 0 ? (double) getSum() / getCount() : 0.0d;
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}
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@Override
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/**
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* {@inheritDoc}
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*
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* Returns a non-empty string representation of this object suitable for
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* debugging. The exact presentation format is unspecified and may vary
|
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* between implementations and versions.
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*/
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public String toString() {
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return String.format(
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"%s{count=%d, sum=%d, min=%d, average=%d, max=%d}",
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this.getClass().getSimpleName(),
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getCount(),
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getSum(),
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getMin(),
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getAverage(),
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getMax());
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}
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}
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182
jdk/src/share/classes/java/util/LongSummaryStatistics.java
Normal file
182
jdk/src/share/classes/java/util/LongSummaryStatistics.java
Normal file
@ -0,0 +1,182 @@
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/*
|
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* Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
|
||||
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
||||
*
|
||||
* This code is free software; you can redistribute it and/or modify it
|
||||
* under the terms of the GNU General Public License version 2 only, as
|
||||
* published by the Free Software Foundation. Oracle designates this
|
||||
* particular file as subject to the "Classpath" exception as provided
|
||||
* by Oracle in the LICENSE file that accompanied this code.
|
||||
*
|
||||
* This code is distributed in the hope that it will be useful, but WITHOUT
|
||||
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
||||
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
||||
* version 2 for more details (a copy is included in the LICENSE file that
|
||||
* accompanied this code).
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License version
|
||||
* 2 along with this work; if not, write to the Free Software Foundation,
|
||||
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
||||
*
|
||||
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
|
||||
* or visit www.oracle.com if you need additional information or have any
|
||||
* questions.
|
||||
*/
|
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package java.util;
|
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|
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import java.util.function.IntConsumer;
|
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import java.util.function.LongConsumer;
|
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|
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/**
|
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* A state object for collecting statistics such as count, min, max, sum, and
|
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* average.
|
||||
*
|
||||
* <p>This class is designed to work with (though does not require)
|
||||
* {@linkplain java.util.stream streams}. For example, you can compute
|
||||
* summary statistics on a stream of longs with:
|
||||
* <pre> {@code
|
||||
* LongSummaryStatistics stats = longStream.collect(LongSummaryStatistics::new,
|
||||
* LongSummaryStatistics::accept,
|
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* LongSummaryStatistics::combine);
|
||||
* }</pre>
|
||||
*
|
||||
* <p>{@code LongSummaryStatistics} can be used as a
|
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* {@linkplain java.util.stream.Stream#reduce(java.util.function.BinaryOperator) reduction}
|
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* target for a {@linkplain java.util.stream.Stream stream}. For example:
|
||||
*
|
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* <pre> {@code
|
||||
* LongSummaryStatistics stats = people.stream()
|
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* .collect(Collectors.toLongSummaryStatistics(Person::getAge));
|
||||
*}</pre>
|
||||
*
|
||||
* This computes, in a single pass, the count of people, as well as the minimum,
|
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* maximum, sum, and average of their ages in milliseconds.
|
||||
*
|
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* @implNote This implementation is not thread safe. However, it is safe to use
|
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* {@link java.util.stream.Collectors#toLongSummaryStatistics(java.util.function.ToLongFunction)
|
||||
* Collectors.toLongStatistics()} on a parallel stream, because the parallel
|
||||
* implementation of {@link java.util.stream.Stream#collect Stream.collect()}
|
||||
* provides the necessary partitioning, isolation, and merging of results for
|
||||
* safe and efficient parallel execution.
|
||||
*
|
||||
* <p>This implementation does not check for overflow of the sum.
|
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* @since 1.8
|
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*/
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public class LongSummaryStatistics implements LongConsumer, IntConsumer {
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private long count;
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private long sum;
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private long min = Long.MAX_VALUE;
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private long max = Long.MIN_VALUE;
|
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|
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/**
|
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* Construct an empty instance with zero count, zero sum,
|
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* {@code Long.MAX_VALUE} min, {@code Long.MIN_VALUE} max and zero
|
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* average.
|
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*/
|
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public LongSummaryStatistics() { }
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|
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/**
|
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* Records a new {@code int} value into the summary information.
|
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*
|
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* @param value the input value
|
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*/
|
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@Override
|
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public void accept(int value) {
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accept((long) value);
|
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}
|
||||
|
||||
/**
|
||||
* Records a new {@code long} value into the summary information.
|
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*
|
||||
* @param value the input value
|
||||
*/
|
||||
@Override
|
||||
public void accept(long value) {
|
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++count;
|
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sum += value;
|
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min = Math.min(min, value);
|
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max = Math.max(max, value);
|
||||
}
|
||||
|
||||
/**
|
||||
* Combines the state of another {@code LongSummaryStatistics} into this
|
||||
* one.
|
||||
*
|
||||
* @param other another {@code LongSummaryStatistics}
|
||||
* @throws NullPointerException if {@code other} is null
|
||||
*/
|
||||
public void combine(LongSummaryStatistics other) {
|
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count += other.count;
|
||||
sum += other.sum;
|
||||
min = Math.min(min, other.min);
|
||||
max = Math.max(max, other.max);
|
||||
}
|
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|
||||
/**
|
||||
* Returns the count of values recorded.
|
||||
*
|
||||
* @return the count of values
|
||||
*/
|
||||
public final long getCount() {
|
||||
return count;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the sum of values recorded, or zero if no values have been
|
||||
* recorded.
|
||||
*
|
||||
* @return the sum of values, or zero if none
|
||||
*/
|
||||
public final long getSum() {
|
||||
return sum;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the minimum value recorded, or {@code Long.MAX_VALUE} if no
|
||||
* values have been recorded.
|
||||
*
|
||||
* @return the minimum value, or {@code Long.MAX_VALUE} if none
|
||||
*/
|
||||
public final long getMin() {
|
||||
return min;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the maximum value recorded, or {@code Long.MIN_VALUE} if no
|
||||
* values have been recorded
|
||||
*
|
||||
* @return the maximum value, or {@code Long.MIN_VALUE} if none
|
||||
*/
|
||||
public final long getMax() {
|
||||
return max;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the average of values recorded, or zero if no values have been
|
||||
* recorded.
|
||||
*
|
||||
* @return The average of values, or zero if none
|
||||
*/
|
||||
public final double getAverage() {
|
||||
return getCount() > 0 ? (double) getSum() / getCount() : 0.0d;
|
||||
}
|
||||
|
||||
@Override
|
||||
/**
|
||||
* {@inheritDoc}
|
||||
*
|
||||
* 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.
|
||||
*/
|
||||
public String toString() {
|
||||
return String.format(
|
||||
"%s{count=%d, sum=%d, min=%d, average=%d, max=%d}",
|
||||
this.getClass().getSimpleName(),
|
||||
getCount(),
|
||||
getSum(),
|
||||
getMin(),
|
||||
getAverage(),
|
||||
getMax());
|
||||
}
|
||||
}
|
Loading…
x
Reference in New Issue
Block a user