From 31f0445ded9cf3cdd94539643171b2c02e94984e Mon Sep 17 00:00:00 2001
From: SteffenLm <33038091+SteffenLm@users.noreply.github.com>
Date: Wed, 23 Aug 2023 17:42:07 +0200
Subject: [PATCH 1/5] Implement Solution
---
Author.java | 3 +++
Book.java | 4 ++++
BookCollection.java | 43 ++++++++++++++++++++++++++++++++++++++
DuplicateKeyException.java | 5 +++++
Exercise.java | 25 +++++++++++++++++++++-
5 files changed, 79 insertions(+), 1 deletion(-)
create mode 100644 Author.java
create mode 100644 Book.java
create mode 100644 BookCollection.java
create mode 100644 DuplicateKeyException.java
diff --git a/Author.java b/Author.java
new file mode 100644
index 0000000..e988398
--- /dev/null
+++ b/Author.java
@@ -0,0 +1,3 @@
+public record Author(String Name) {
+
+}
\ No newline at end of file
diff --git a/Book.java b/Book.java
new file mode 100644
index 0000000..f34ef89
--- /dev/null
+++ b/Book.java
@@ -0,0 +1,4 @@
+public record Book(String title) {
+
+
+}
\ No newline at end of file
diff --git a/BookCollection.java b/BookCollection.java
new file mode 100644
index 0000000..14aa644
--- /dev/null
+++ b/BookCollection.java
@@ -0,0 +1,43 @@
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map.Entry;
+import java.util.Optional;
+
+public record BookCollection(HashMap<Author, List<Book>> collection) {
+
+ public void addAuthor(Author author) throws DuplicateKeyException {
+ if (collection.containsKey(author)) {
+ throw new DuplicateKeyException();
+ }
+
+ collection.put(author, new ArrayList<>());
+ }
+
+ public void addBook(Author author, Book book) {
+ collection.get(author).add(book);
+ }
+
+ public Optional<Book> getBookByTitle(String title) {
+ for (List<Book> books : collection.values()) {
+ for (Book b : books) {
+ if (b.title().equals(title)) {
+ return Optional.of(b);
+ }
+ }
+ }
+ return Optional.empty();
+ }
+
+ public Optional<Author> getMostDiligentAuthor() {
+ Author mostDiligentAuthor = null;
+ int mostBooks = 0;
+ for (Entry<Author, List<Book>> entry : collection.entrySet()) {
+ if (entry.getValue().size() > mostBooks) {
+ mostDiligentAuthor = entry.getKey();
+ mostBooks = entry.getValue().size();
+ }
+ }
+ return Optional.ofNullable(mostDiligentAuthor);
+ }
+}
\ No newline at end of file
diff --git a/DuplicateKeyException.java b/DuplicateKeyException.java
new file mode 100644
index 0000000..50f898b
--- /dev/null
+++ b/DuplicateKeyException.java
@@ -0,0 +1,5 @@
+public class DuplicateKeyException extends Exception {
+
+ private static final long serialVersionUID = 1L;
+
+}
\ No newline at end of file
diff --git a/Exercise.java b/Exercise.java
index 3c092f9..4b4c209 100644
--- a/Exercise.java
+++ b/Exercise.java
@@ -1,6 +1,29 @@
+import java.util.HashMap;
+
public class Exercise {
public static void main(String[] args) {
- // implement exercise here
+ BookCollection collection = new BookCollection(new HashMap<>());
+
+ try {
+ collection.addAuthor(new Author("Stephen King"));
+ collection.addAuthor(new Author("George RR Martin"));
+ } catch (DuplicateKeyException e) {
+ e.printStackTrace();
+ }
+
+ collection.addBook(new Author("Stephen King"), new Book("Es"));
+ collection.addBook(new Author("Stephen King"), new Book("Sie"));
+ collection.addBook(new Author("George RR Martin"), new Book("Das Lied von Eis und Feuer 1"));
+ collection.addBook(new Author("George RR Martin"), new Book("Das Lied von Eis und Feuer 2"));
+ collection.addBook(new Author("George RR Martin"), new Book("Das Lied von Eis und Feuer 3"));
+ collection.addBook(new Author("George RR Martin"), new Book("Das Lied von Eis und Feuer 4"));
+ collection.addBook(new Author("George RR Martin"), new Book("Das Lied von Eis und Feuer 5"));
+ collection.addBook(new Author("George RR Martin"), new Book("Das Lied von Eis und Feuer 6"));
+
+ System.out.println(collection.getBookByTitle("Das Lied von Eis und Feuer 5"));
+ System.out.println(collection.getMostDiligentAuthor());
+
}
+
}
From f625ac75cac689c3d4b5fa04a51addc979dd7a2f Mon Sep 17 00:00:00 2001
From: github-actions <>
Date: Wed, 23 Aug 2023 15:42:55 +0000
Subject: [PATCH 2/5] Google Java Format
---
Author.java | 4 +--
Book.java | 5 +---
BookCollection.java | 56 +++++++++++++++++++-------------------
DuplicateKeyException.java | 5 ++--
Exercise.java | 2 --
5 files changed, 32 insertions(+), 40 deletions(-)
diff --git a/Author.java b/Author.java
index e988398..9694c0e 100644
--- a/Author.java
+++ b/Author.java
@@ -1,3 +1 @@
-public record Author(String Name) {
-
-}
\ No newline at end of file
+public record Author(String Name) {}
diff --git a/Book.java b/Book.java
index f34ef89..19ad242 100644
--- a/Book.java
+++ b/Book.java
@@ -1,4 +1 @@
-public record Book(String title) {
-
-
-}
\ No newline at end of file
+public record Book(String title) {}
diff --git a/BookCollection.java b/BookCollection.java
index 14aa644..b7a725d 100644
--- a/BookCollection.java
+++ b/BookCollection.java
@@ -6,38 +6,38 @@
public record BookCollection(HashMap<Author, List<Book>> collection) {
- public void addAuthor(Author author) throws DuplicateKeyException {
- if (collection.containsKey(author)) {
- throw new DuplicateKeyException();
- }
-
- collection.put(author, new ArrayList<>());
+ public void addAuthor(Author author) throws DuplicateKeyException {
+ if (collection.containsKey(author)) {
+ throw new DuplicateKeyException();
}
- public void addBook(Author author, Book book) {
- collection.get(author).add(book);
- }
+ collection.put(author, new ArrayList<>());
+ }
- public Optional<Book> getBookByTitle(String title) {
- for (List<Book> books : collection.values()) {
- for (Book b : books) {
- if (b.title().equals(title)) {
- return Optional.of(b);
- }
- }
+ public void addBook(Author author, Book book) {
+ collection.get(author).add(book);
+ }
+
+ public Optional<Book> getBookByTitle(String title) {
+ for (List<Book> books : collection.values()) {
+ for (Book b : books) {
+ if (b.title().equals(title)) {
+ return Optional.of(b);
}
- return Optional.empty();
+ }
}
+ return Optional.empty();
+ }
- public Optional<Author> getMostDiligentAuthor() {
- Author mostDiligentAuthor = null;
- int mostBooks = 0;
- for (Entry<Author, List<Book>> entry : collection.entrySet()) {
- if (entry.getValue().size() > mostBooks) {
- mostDiligentAuthor = entry.getKey();
- mostBooks = entry.getValue().size();
- }
- }
- return Optional.ofNullable(mostDiligentAuthor);
+ public Optional<Author> getMostDiligentAuthor() {
+ Author mostDiligentAuthor = null;
+ int mostBooks = 0;
+ for (Entry<Author, List<Book>> entry : collection.entrySet()) {
+ if (entry.getValue().size() > mostBooks) {
+ mostDiligentAuthor = entry.getKey();
+ mostBooks = entry.getValue().size();
+ }
}
-}
\ No newline at end of file
+ return Optional.ofNullable(mostDiligentAuthor);
+ }
+}
diff --git a/DuplicateKeyException.java b/DuplicateKeyException.java
index 50f898b..0917539 100644
--- a/DuplicateKeyException.java
+++ b/DuplicateKeyException.java
@@ -1,5 +1,4 @@
public class DuplicateKeyException extends Exception {
- private static final long serialVersionUID = 1L;
-
-}
\ No newline at end of file
+ private static final long serialVersionUID = 1L;
+}
diff --git a/Exercise.java b/Exercise.java
index 4b4c209..14125d0 100644
--- a/Exercise.java
+++ b/Exercise.java
@@ -23,7 +23,5 @@ public static void main(String[] args) {
System.out.println(collection.getBookByTitle("Das Lied von Eis und Feuer 5"));
System.out.println(collection.getMostDiligentAuthor());
-
}
-
}
From 4a624fd915ac1b0fe1d2b3d88e215409cdd6351a Mon Sep 17 00:00:00 2001
From: SteffenLm <33038091+SteffenLm@users.noreply.github.com>
Date: Wed, 5 Jun 2024 21:59:19 +0200
Subject: [PATCH 3/5] fix solution according to description and diagramm
---
BookCollection.java | 10 +++++-----
DuplicateKeyException.java | 2 --
2 files changed, 5 insertions(+), 7 deletions(-)
diff --git a/BookCollection.java b/BookCollection.java
index b7a725d..01cb601 100644
--- a/BookCollection.java
+++ b/BookCollection.java
@@ -18,18 +18,18 @@ public void addBook(Author author, Book book) {
collection.get(author).add(book);
}
- public Optional<Book> getBookByTitle(String title) {
+ public Book getBookByTitle(String title) {
for (List<Book> books : collection.values()) {
for (Book b : books) {
if (b.title().equals(title)) {
- return Optional.of(b);
+ return b;
}
}
}
- return Optional.empty();
+ return null;
}
- public Optional<Author> getMostDiligentAuthor() {
+ public Author getMostDiligentAuthor() {
Author mostDiligentAuthor = null;
int mostBooks = 0;
for (Entry<Author, List<Book>> entry : collection.entrySet()) {
@@ -38,6 +38,6 @@ public Optional<Author> getMostDiligentAuthor() {
mostBooks = entry.getValue().size();
}
}
- return Optional.ofNullable(mostDiligentAuthor);
+ return mostDiligentAuthor;
}
}
diff --git a/DuplicateKeyException.java b/DuplicateKeyException.java
index 0917539..6213685 100644
--- a/DuplicateKeyException.java
+++ b/DuplicateKeyException.java
@@ -1,4 +1,2 @@
public class DuplicateKeyException extends Exception {
-
- private static final long serialVersionUID = 1L;
}
From dded37187ac2265991084bcdf0ca3651c4c4fa3c Mon Sep 17 00:00:00 2001
From: SteffenLm <33038091+SteffenLm@users.noreply.github.com>
Date: Wed, 5 Jun 2024 21:59:33 +0200
Subject: [PATCH 4/5] fix imports
---
BookCollection.java | 1 -
1 file changed, 1 deletion(-)
diff --git a/BookCollection.java b/BookCollection.java
index 01cb601..688804d 100644
--- a/BookCollection.java
+++ b/BookCollection.java
@@ -2,7 +2,6 @@
import java.util.HashMap;
import java.util.List;
import java.util.Map.Entry;
-import java.util.Optional;
public record BookCollection(HashMap<Author, List<Book>> collection) {
From 049ac015d6ad36ddb8abcd46034cca933b434697 Mon Sep 17 00:00:00 2001
From: github-actions <>
Date: Wed, 5 Jun 2024 19:59:51 +0000
Subject: [PATCH 5/5] Google Java Format
---
DuplicateKeyException.java | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/DuplicateKeyException.java b/DuplicateKeyException.java
index 6213685..f6b572c 100644
--- a/DuplicateKeyException.java
+++ b/DuplicateKeyException.java
@@ -1,2 +1 @@
-public class DuplicateKeyException extends Exception {
-}
+public class DuplicateKeyException extends Exception {}