From e7301029c346147df75c1b256a7ee8b50fc273b3 Mon Sep 17 00:00:00 2001 From: soufiane-cheouati <46105138+soufiane-cheouati@users.noreply.github.com> Date: Tue, 15 Jan 2019 16:37:38 +0000 Subject: [PATCH] Adding new methods for calculating the sum (#6088) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * Creating new module Creating new module for Hexagonal Architecture * Adding Java classes Adding Java classes used in the example * Adding the pom.xml file Adding the pom.xml file. * Update the pom.xml file Update the pom.xml file * BAEL-2498: Creating new folder Creating new folder for Java 8 sum with Streams examples * BAEL-2498: Uploading java Classes Adding the Java classes containing examples of different methods to calculate the sum using Java 8 Streams * BAEL-2498: Creating new folder Creating new folder for sum unit tests * BAEL-2498: Adding the unit tests Adding the unit tests for the methods that calculate the sum using the Java Streams * Add files via Upload - Adding a method for calculating the sum of a map´s values - Adding a method for calculating the sum of numbers within a String object * Add files via upload - Adding a method for calculating the sum of a map´s values - Adding a method for calculating the sum of numbers within a String object * Delete . ... * Delete pom.xml * Delete User.java * Delete UserControler.java * Delete UserDataBaseAdapter.java * Delete UserInterfaceAdapter.java * Delete UserDataBasePort.java * Delete UserInterfacePort.java * Delete UserService.java --- .../main/java/com/baeldung/stream/sum/. .. | 1 + .../baeldung/stream/sum/ArithmeticUtils.java | 8 ++ .../java/com/baeldung/stream/sum/Item.java | 31 ++++ .../stream/sum/StreamSumCalculator.java | 59 ++++++++ .../sum/StreamSumCalculatorWithObject.java | 38 +++++ .../test/java/com/baeldung/stream/sum/. .. | 1 + .../stream/sum/StreamSumUnitTest.java | 136 ++++++++++++++++++ 7 files changed, 274 insertions(+) create mode 100644 java-streams/src/main/java/com/baeldung/stream/sum/. .. create mode 100644 java-streams/src/main/java/com/baeldung/stream/sum/ArithmeticUtils.java create mode 100644 java-streams/src/main/java/com/baeldung/stream/sum/Item.java create mode 100644 java-streams/src/main/java/com/baeldung/stream/sum/StreamSumCalculator.java create mode 100644 java-streams/src/main/java/com/baeldung/stream/sum/StreamSumCalculatorWithObject.java create mode 100644 java-streams/src/test/java/com/baeldung/stream/sum/. .. create mode 100644 java-streams/src/test/java/com/baeldung/stream/sum/StreamSumUnitTest.java diff --git a/java-streams/src/main/java/com/baeldung/stream/sum/. .. b/java-streams/src/main/java/com/baeldung/stream/sum/. .. new file mode 100644 index 0000000000..8b13789179 --- /dev/null +++ b/java-streams/src/main/java/com/baeldung/stream/sum/. .. @@ -0,0 +1 @@ + diff --git a/java-streams/src/main/java/com/baeldung/stream/sum/ArithmeticUtils.java b/java-streams/src/main/java/com/baeldung/stream/sum/ArithmeticUtils.java new file mode 100644 index 0000000000..3170b1fb31 --- /dev/null +++ b/java-streams/src/main/java/com/baeldung/stream/sum/ArithmeticUtils.java @@ -0,0 +1,8 @@ +package com.baeldung.stream.sum; + +public class ArithmeticUtils { + + public static int add(int a, int b) { + return a + b; + } +} diff --git a/java-streams/src/main/java/com/baeldung/stream/sum/Item.java b/java-streams/src/main/java/com/baeldung/stream/sum/Item.java new file mode 100644 index 0000000000..2f162d6eda --- /dev/null +++ b/java-streams/src/main/java/com/baeldung/stream/sum/Item.java @@ -0,0 +1,31 @@ +package com.baeldung.stream.sum; + +public class Item { + + private int id; + private Integer price; + + public Item(int id, Integer price) { + super(); + this.id = id; + this.price = price; + } + + // Standard getters and setters + public long getId() { + return id; + } + + public void setId(int id) { + this.id = id; + } + + public Integer getPrice() { + return price; + } + + public void setPrice(Integer price) { + this.price = price; + } + +} diff --git a/java-streams/src/main/java/com/baeldung/stream/sum/StreamSumCalculator.java b/java-streams/src/main/java/com/baeldung/stream/sum/StreamSumCalculator.java new file mode 100644 index 0000000000..2f63cf8629 --- /dev/null +++ b/java-streams/src/main/java/com/baeldung/stream/sum/StreamSumCalculator.java @@ -0,0 +1,59 @@ +package com.baeldung.stream.sum; + +import java.util.Arrays; +import java.util.List; +import java.util.Map; +import java.util.stream.Collectors; + +public class StreamSumCalculator { + + public static Integer getSumUsingCustomizedAccumulator(List integers) { + return integers.stream() + .reduce(0, ArithmeticUtils::add); + + } + + public static Integer getSumUsingJavaAccumulator(List integers) { + return integers.stream() + .reduce(0, Integer::sum); + + } + + public static Integer getSumUsingReduce(List integers) { + return integers.stream() + .reduce(0, (a, b) -> a + b); + + } + + public static Integer getSumUsingCollect(List integers) { + + return integers.stream() + .collect(Collectors.summingInt(Integer::intValue)); + + } + + public static Integer getSumUsingSum(List integers) { + + return integers.stream() + .mapToInt(Integer::intValue) + .sum(); + } + + public static Integer getSumOfMapValues(Map map) { + + return map.values() + .stream() + .mapToInt(Integer::valueOf) + .sum(); + } + + public static Integer getSumIntegersFromString(String str) { + + Integer sum = Arrays.stream(str.split(" ")) + .filter((s) -> s.matches("\\d+")) + .mapToInt(Integer::valueOf) + .sum(); + + return sum; + } +} diff --git a/java-streams/src/main/java/com/baeldung/stream/sum/StreamSumCalculatorWithObject.java b/java-streams/src/main/java/com/baeldung/stream/sum/StreamSumCalculatorWithObject.java new file mode 100644 index 0000000000..b83616928e --- /dev/null +++ b/java-streams/src/main/java/com/baeldung/stream/sum/StreamSumCalculatorWithObject.java @@ -0,0 +1,38 @@ +package com.baeldung.stream.sum; + +import java.util.List; +import java.util.stream.Collectors; + +public class StreamSumCalculatorWithObject { + + public static Integer getSumUsingCustomizedAccumulator(List items) { + return items.stream() + .map(x -> x.getPrice()) + .reduce(0, ArithmeticUtils::add); + } + + public static Integer getSumUsingJavaAccumulator(List items) { + return items.stream() + .map(x -> x.getPrice()) + .reduce(0, Integer::sum); + } + + public static Integer getSumUsingReduce(List items) { + return items.stream() + .map(item -> item.getPrice()) + .reduce(0, (a, b) -> a + b); + } + + public static Integer getSumUsingCollect(List items) { + return items.stream() + .map(x -> x.getPrice()) + .collect(Collectors.summingInt(Integer::intValue)); + } + + public static Integer getSumUsingSum(List items) { + return items.stream() + .mapToInt(x -> x.getPrice()) + .sum(); + } + +} diff --git a/java-streams/src/test/java/com/baeldung/stream/sum/. .. b/java-streams/src/test/java/com/baeldung/stream/sum/. .. new file mode 100644 index 0000000000..8b13789179 --- /dev/null +++ b/java-streams/src/test/java/com/baeldung/stream/sum/. .. @@ -0,0 +1 @@ + diff --git a/java-streams/src/test/java/com/baeldung/stream/sum/StreamSumUnitTest.java b/java-streams/src/test/java/com/baeldung/stream/sum/StreamSumUnitTest.java new file mode 100644 index 0000000000..46e1af9a4a --- /dev/null +++ b/java-streams/src/test/java/com/baeldung/stream/sum/StreamSumUnitTest.java @@ -0,0 +1,136 @@ +package com.baeldung.stream.sum; + +import static org.junit.jupiter.api.Assertions.assertEquals; + +import java.util.Arrays; +import java.util.HashMap; +import java.util.List; +import java.util.Map; + +import org.junit.jupiter.api.Test; + +public class StreamSumUnitTest { + + @Test + public void givenListOfIntegersWhenSummingUsingCustomizedAccumulatorThenCorrectValueReturned() { + List integers = Arrays.asList(1, 2, 3, 4, 5); + Integer sum = StreamSumCalculator.getSumUsingCustomizedAccumulator(integers); + assertEquals(15, sum.intValue()); + + } + + @Test + public void givenListOfIntegersWhenSummingUsingJavaAccumulatorThenCorrectValueReturned() { + List integers = Arrays.asList(1, 2, 3, 4, 5); + Integer sum = StreamSumCalculator.getSumUsingJavaAccumulator(integers); + assertEquals(15, sum.intValue()); + } + + @Test + public void givenListOfIntegersWhenSummingUsingReduceThenCorrectValueReturned() { + List integers = Arrays.asList(1, 2, 3, 4, 5); + Integer sum = StreamSumCalculator.getSumUsingReduce(integers); + assertEquals(15, sum.intValue()); + } + + @Test + public void givenListOfIntegersWhenSummingUsingCollectThenCorrectValueReturned() { + List integers = Arrays.asList(1, 2, 3, 4, 5); + Integer sum = StreamSumCalculator.getSumUsingCollect(integers); + assertEquals(15, sum.intValue()); + } + + @Test + public void givenListOfIntegersWhenSummingUsingSumThenCorrectValueReturned() { + List integers = Arrays.asList(1, 2, 3, 4, 5); + Integer sum = StreamSumCalculator.getSumUsingSum(integers); + assertEquals(15, sum.intValue()); + } + + @Test + public void givenListOfItemsWhenSummingUsingCustomizedAccumulatorThenCorrectValueReturned() { + Item item1 = new Item(1, 10); + Item item2 = new Item(2, 15); + Item item3 = new Item(3, 25); + Item item4 = new Item(4, 40); + + List items = Arrays.asList(item1, item2, item3, item4); + + Integer sum = StreamSumCalculatorWithObject.getSumUsingCustomizedAccumulator(items); + assertEquals(90, sum.intValue()); + + } + + @Test + public void givenListOfItemsWhenSummingUsingJavaAccumulatorThenCorrectValueReturned() { + Item item1 = new Item(1, 10); + Item item2 = new Item(2, 15); + Item item3 = new Item(3, 25); + Item item4 = new Item(4, 40); + + List items = Arrays.asList(item1, item2, item3, item4); + + Integer sum = StreamSumCalculatorWithObject.getSumUsingJavaAccumulator(items); + assertEquals(90, sum.intValue()); + } + + @Test + public void givenListOfItemsWhenSummingUsingReduceThenCorrectValueReturned() { + Item item1 = new Item(1, 10); + Item item2 = new Item(2, 15); + Item item3 = new Item(3, 25); + Item item4 = new Item(4, 40); + + List items = Arrays.asList(item1, item2, item3, item4); + + Integer sum = StreamSumCalculatorWithObject.getSumUsingReduce(items); + assertEquals(90, sum.intValue()); + } + + @Test + public void givenListOfItemsWhenSummingUsingCollectThenCorrectValueReturned() { + Item item1 = new Item(1, 10); + Item item2 = new Item(2, 15); + Item item3 = new Item(3, 25); + Item item4 = new Item(4, 40); + + List items = Arrays.asList(item1, item2, item3, item4); + + Integer sum = StreamSumCalculatorWithObject.getSumUsingCollect(items); + assertEquals(90, sum.intValue()); + } + + @Test + public void givenListOfItemsWhenSummingUsingSumThenCorrectValueReturned() { + Item item1 = new Item(1, 10); + Item item2 = new Item(2, 15); + Item item3 = new Item(3, 25); + Item item4 = new Item(4, 40); + + List items = Arrays.asList(item1, item2, item3, item4); + + Integer sum = StreamSumCalculatorWithObject.getSumUsingSum(items); + assertEquals(90, sum.intValue()); + } + + @Test + public void givenMapWhenSummingThenCorrectValueReturned() { + Map map = new HashMap(); + map.put(1, 10); + map.put(2, 15); + map.put(3, 25); + map.put(4, 40); + + Integer sum = StreamSumCalculator.getSumOfMapValues(map); + assertEquals(90, sum.intValue()); + } + + @Test + public void givenStringWhenSummingThenCorrectValueReturned() { + String string = "Item1 10 Item2 25 Item3 30 Item4 45"; + + Integer sum = StreamSumCalculator.getSumIntegersFromString(string); + assertEquals(110, sum.intValue()); + } + +}