8000 Functional Style Programming - a Deep Dive · 2714rohit/Java-Coding-Problems@a4e3fe1 · GitHub
[go: up one dir, main page]
Skip to content

Commit a4e3fe1

Browse files
AnghelLeonardAnghelLeonard
committed
Functional Style Programming - a Deep Dive
1 parent becaa60 commit a4e3fe1

File tree

5 files changed

+183
-0
lines changed

5 files changed

+183
-0
lines changed

‎Chapter09/BONUS_1_ArrayToStreamAndBack/README.md

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,2 @@
1+
# Map a stream
2+
Write a helper method that uses **Stream#map()** to convert **List< P >** in **List< Q >**. Write a heper method that does the same thing for arrays.

‎Chapter09/BONUS_1_ArrayToStreamAndBack/pom.xml

Lines changed: 14 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,14 @@
1+
<?xml version="1.0" encoding="UTF-8"?>
2+
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
3+
<modelVersion>4.0.0</modelVersion>
4+
<groupId>coding.challenge</groupId>
5+
<artifactId>BONUS_1_ArrayToStreamAndBack</artifactId>
6+
<version>1.0</version>
7+
<packaging>jar</packaging>
8+
<properties>
9+
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
10+
<maven.compiler.source>13</maven.compiler.source>
11+
<maven.compiler.target>13</maven.compiler.target>
12+
</properties>
13+
<name>BONUS_1_ArrayToStreamAndBack</name>
14+
</project>

‎Chapter09/BONUS_1_ArrayToStreamAndBack/src/main/java/modern/challenge/Convertors.java

Lines changed: 62 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,62 @@
1+
package modern.challenge;
2+
3+
import java.util.Arrays;
4+
import java.util.stream.IntStream;
5+
import java.util.stream.Stream;
6+
7+
public final class Convertors {
8+
9+
private Convertors() {
10+
throw new AssertionError("Cannot be instantiated");
11+
}
12+
13+
// Convert array of T to stream via Arrays#stream()
14+
public static <T> Stream<T> toStream1(T[] arr) {
15+
16+
if (arr == null) {
17+
throw new IllegalArgumentException("Inputs cannot be null&qu 8000 ot;);
18+
}
19+
20+
return Arrays.stream(arr);
21+
}
22+
23+
// Convert array of T to stream via Stream#of()
24+
public static <T> Stream<T> toStream2(T[] arr) {
25+
26+
if (arr == null) {
27+
throw new IllegalArgumentException("Inputs cannot be null");
28+
}
29+
30+
return Stream.of(arr);
31+
}
32+
33+
// Convert array of T to stream via List#stream()
34+
public static <T> Stream<T> toStream3(T[] arr) {
35+
36+
if (arr == null) {
37+
throw new IllegalArgumentException("Inputs cannot be null");
38+
}
39+
40+
return Arrays.asList(arr).stream();
41+
}
42+
43+
// Convert array of primitves (int) to stream via Arrays#stream()
44+
public static IntStream toStream4(int[] arr) {
45+
46+
if (arr == null) {
47+
throw new IllegalArgumentException("Inputs cannot be null");
48+
}
49+
50+
return Arrays.stream(arr);
51+
}
52+
53+
// Convert array of primitves (int) to stream via IntStream#of()
54+
public static IntStream toStream5(int[] arr) {
55+
56+
if (arr == null) {
57+
throw new IllegalArgumentException("Inputs cannot be null");
58+
}
59+
60+
return IntStream.of(arr);
61+
}
62+
}

‎Chapter09/BONUS_1_ArrayToStreamAndBack/src/main/java/modern/challenge/Main.java

Lines changed: 35 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,35 @@
1+
package modern.challenge;
2+
3+
public class Main {
4+
5+
public static void main(String[] args) {
6+
7+
Melon[] melons = {
8+
new Melon("Gac", 1200),
9+
new Melon("Hemi", 2300),
10+
new Melon("Apollo", 3400)
11+
};
12+
13+
int[] weights = {1200, 2300, 3400};
14+
15+
System.out.println("Array of melons to stream (toStream1()):");
16+
Convertors.toStream1(melons)
17+
.forEach(System.out::println);
18+
19+
System.out.println("\n\nArray of melons to stream (toStream2()):");
20+
Convertors.toStream2(melons)
21+
.forEach(System.out::println);
22+
23+
System.out.println("\n\nArray of melons to stream (toStream3()):");
24+
Convertors.toStream3(melons)
25+
.forEach(System.out::println);
26+
27+
System.out.println("\n\nArray of integers to stream (toStream4()):");
28+
Convertors.toStream4(weights)
29+
.forEach(System.out::println);
30+
31+
System.out.println("\n\nArray of integers to stream (toStream5()):");
32+
Convertors.toStream5(weights)
33+
.forEach(System.out::println);
34+
}
35+
}

‎Chapter09/BONUS_1_ArrayToStreamAndBack/src/main/java/modern/challenge/Melon.java

Lines changed: 70 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,70 @@
1+
package modern.challenge;
2+
3+
import java.util.Objects;
4+
5+
public class Melon {
6+
7+
private String type;
8+
private int weight;
9+
10+
public Melon(String type, int weight) {
11+
this.type = type;
12+
this.weight = weight;
13+
}
14+
15+
public String getType() {
16+
return type;
17+
}
18+
19+
public int getWeight() {
20+
return weight;
21+
}
22+
23+
public void setType(String type) {
24+
this.type = type;
25+
}
26+
27+
public void setWeight(int weight) {
28+
this.weight = weight;
29+
}
30+
31+
@Override
32+
public String toString() {
33+
return type + "(" + weight + "g)";
34+
}
35+
36+
@Override
37+
public int hashCode() {
38+
int hash = 7;
39+
hash = 37 * hash + Objects.hashCode(this.type);
40+
hash = 37 * hash + this.weight;
41+
return hash;
42+
}
43+
44+
@Override
45+
public boolean equals(Object obj) {
46+
47+
if (this == obj) {
48+
return true;
49+
}
50+
51+
if (obj == null) {
52+
return false;
53+
}
54+
55+
if (getClass() != obj.getClass()) {
56+
return false;
57+
}
58+
59+
final Melon other = (Melon) obj;
60+
if (this.weight != other.weight) {
61+
return false;
62+
}
63+
64+
if (!Objects.equals(this.type, other.type)) {
65+
return false;
66+
}
67+
return true;
68+
}
69+
70+
}

0 commit comments

Comments
 (0)
0