From 47169d5907cf969f8b8e2a4265821886c7a4fe5b Mon Sep 17 00:00:00 2001
From: Hallvard Traetteberg <hal@ntnu.no>
Date: Thu, 29 Oct 2020 11:31:38 +0100
Subject: [PATCH] antipatterns
---
antipatterns/.gitignore | 3 ++
antipatterns/pom.xml | 47 +++++++++++++++++++
.../DataClassWithEffectivelyFinalFields.java | 20 ++++++++
.../DataClassWithLittleLogic.java | 35 ++++++++++++++
.../antipatterns/DataClassWithValidation.java | 26 ++++++++++
.../antipatterns/NonEncapsulatedList.java | 21 +++++++++
.../DataClassWithLittleLogicTest.java | 32 +++++++++++++
.../DataClassWithValidationTest.java | 34 ++++++++++++++
8 files changed, 218 insertions(+)
create mode 100644 antipatterns/.gitignore
create mode 100644 antipatterns/pom.xml
create mode 100644 antipatterns/src/main/java/antipatterns/DataClassWithEffectivelyFinalFields.java
create mode 100644 antipatterns/src/main/java/antipatterns/DataClassWithLittleLogic.java
create mode 100644 antipatterns/src/main/java/antipatterns/DataClassWithValidation.java
create mode 100644 antipatterns/src/main/java/antipatterns/NonEncapsulatedList.java
create mode 100644 antipatterns/src/test/java/antipatterns/DataClassWithLittleLogicTest.java
create mode 100644 antipatterns/src/test/java/antipatterns/DataClassWithValidationTest.java
diff --git a/antipatterns/.gitignore b/antipatterns/.gitignore
new file mode 100644
index 0000000..9a89c84
--- /dev/null
+++ b/antipatterns/.gitignore
@@ -0,0 +1,3 @@
+target/
+.classpath
+.project
diff --git a/antipatterns/pom.xml b/antipatterns/pom.xml
new file mode 100644
index 0000000..c7dfe47
--- /dev/null
+++ b/antipatterns/pom.xml
@@ -0,0 +1,47 @@
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+ <modelVersion>4.0.0</modelVersion>
+ <groupId>it1901</groupId>
+ <artifactId>antipatterns</artifactId>
+ <version>0.0.1-SNAPSHOT</version>
+
+ <dependencies>
+
+ <!-- Test with JUnit5 -->
+ <dependency>
+ <groupId>org.junit.jupiter</groupId>
+ <artifactId>junit-jupiter-api</artifactId>
+ <version>5.4.2</version>
+ <scope>test</scope>
+ </dependency>
+ <dependency>
+ <groupId>org.junit.jupiter</groupId>
+ <artifactId>junit-jupiter-engine</artifactId>
+ <version>5.4.2</version>
+ <scope>test</scope>
+ </dependency>
+ </dependencies>
+
+ <build>
+ <plugins>
+ <!-- Compiling code -->
+ <plugin>
+ <artifactId>maven-compiler-plugin</artifactId>
+ <version>3.8.1</version>
+ <configuration>
+ <encoding>UTF-8</encoding>
+ <release>13</release>
+ </configuration>
+ </plugin>
+ <plugin>
+ <groupId>org.apache.maven.plugins</groupId>
+ <artifactId>maven-surefire-plugin</artifactId>
+ <version>3.0.0-M5</version>
+ <!--
+ <configuration>
+ <argLine>${argLine} dash dash add-exports javafx.graphics/com.sun.javafx.application=ALL-UNNAMED</argLine>
+ </configuration>
+ -->
+ </plugin>
+ </plugins>
+ </build>
+</project>
\ No newline at end of file
diff --git a/antipatterns/src/main/java/antipatterns/DataClassWithEffectivelyFinalFields.java b/antipatterns/src/main/java/antipatterns/DataClassWithEffectivelyFinalFields.java
new file mode 100644
index 0000000..f5b4597
--- /dev/null
+++ b/antipatterns/src/main/java/antipatterns/DataClassWithEffectivelyFinalFields.java
@@ -0,0 +1,20 @@
+package antipatterns;
+
+public class DataClassWithEffectivelyFinalFields {
+
+ private final String name; // should be final
+ private final int number; // should be final
+
+ public DataClassWithEffectivelyFinalFields(final String name, final int number) {
+ this.name = name;
+ this.number = number;
+ }
+
+ public String getName() {
+ return name;
+ }
+
+ public int getNumber() {
+ return number;
+ }
+}
diff --git a/antipatterns/src/main/java/antipatterns/DataClassWithLittleLogic.java b/antipatterns/src/main/java/antipatterns/DataClassWithLittleLogic.java
new file mode 100644
index 0000000..5549e27
--- /dev/null
+++ b/antipatterns/src/main/java/antipatterns/DataClassWithLittleLogic.java
@@ -0,0 +1,35 @@
+package antipatterns;
+
+// ok, but see the test
+public class DataClassWithLittleLogic {
+
+ private String name;
+ private int number;
+
+ public DataClassWithLittleLogic(final String name, final int number) {
+ this.name = name;
+ this.number = number;
+ }
+
+ @Override
+ public String toString() {
+ return String.format("[DataClassWithLittleLogic name=%s number=%s]", name, number);
+ }
+
+ public DataClassWithLittleLogic() {
+ }
+
+ public String getName() {
+ return name;
+ }
+ public void setName(final String name) {
+ this.name = name;
+ }
+
+ public int getNumber() {
+ return number;
+ }
+ public void setNumber(final int number) {
+ this.number = number;
+ }
+}
diff --git a/antipatterns/src/main/java/antipatterns/DataClassWithValidation.java b/antipatterns/src/main/java/antipatterns/DataClassWithValidation.java
new file mode 100644
index 0000000..2569b6c
--- /dev/null
+++ b/antipatterns/src/main/java/antipatterns/DataClassWithValidation.java
@@ -0,0 +1,26 @@
+package antipatterns;
+
+// see DataClassWithValidationTest
+public class DataClassWithValidation {
+
+ private String name;
+
+ public DataClassWithValidation(final String name) {
+ // should use setName to ensure validation logic is run
+ this.name = name;
+ }
+
+ public DataClassWithValidation() {
+ }
+
+ public String getName() {
+ return name;
+ }
+ public void setName(final String name) {
+ if (name.startsWith(" ")) {
+ // should rather use trim() or strip() and check the length
+ throw new IllegalArgumentException("Name cannot begin with blank");
+ }
+ this.name = name;
+ }
+}
diff --git a/antipatterns/src/main/java/antipatterns/NonEncapsulatedList.java b/antipatterns/src/main/java/antipatterns/NonEncapsulatedList.java
new file mode 100644
index 0000000..d8882d2
--- /dev/null
+++ b/antipatterns/src/main/java/antipatterns/NonEncapsulatedList.java
@@ -0,0 +1,21 @@
+package antipatterns;
+
+import java.util.Collection;
+import java.util.Iterator;
+
+public class NonEncapsulatedList implements Iterable<String> {
+
+ private final Collection<String> names;
+
+ public NonEncapsulatedList(final Collection<String> names) {
+ this.names = names;
+ }
+
+ public Collection<String> getNames() {
+ return names;
+ }
+
+ public Iterator<String> iterator() {
+ return names.iterator();
+ }
+}
diff --git a/antipatterns/src/test/java/antipatterns/DataClassWithLittleLogicTest.java b/antipatterns/src/test/java/antipatterns/DataClassWithLittleLogicTest.java
new file mode 100644
index 0000000..3090452
--- /dev/null
+++ b/antipatterns/src/test/java/antipatterns/DataClassWithLittleLogicTest.java
@@ -0,0 +1,32 @@
+package antipatterns;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class DataClassWithLittleLogicTest {
+
+ private DataClassWithLittleLogic instance1, instance2;
+
+ @BeforeEach
+ public void setup() {
+ instance1 = new DataClassWithLittleLogic();
+ instance2 = new DataClassWithLittleLogic("High", 5);
+ }
+
+ @Test
+ public void testConstructor() {
+ Assertions.assertEquals("High", instance2.getName());
+ }
+
+ @Test
+ public void testToString() {
+ Assertions.assertEquals("[DataClassWithLittleLogic name=High number=5]", instance2.toString());
+ }
+
+ @Test
+ public void testSetName() {
+ instance1.setName("Low");
+ Assertions.assertEquals("Low", instance1.getName());
+ }
+}
diff --git a/antipatterns/src/test/java/antipatterns/DataClassWithValidationTest.java b/antipatterns/src/test/java/antipatterns/DataClassWithValidationTest.java
new file mode 100644
index 0000000..a497e5a
--- /dev/null
+++ b/antipatterns/src/test/java/antipatterns/DataClassWithValidationTest.java
@@ -0,0 +1,34 @@
+package antipatterns;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class DataClassWithValidationTest {
+
+ @Test
+ public void testSetName() {
+ try {
+ new DataClassWithValidation(" name starting with blank");
+ Assertions.fail("Should throw IllegalArgumentException");
+ } catch (final IllegalArgumentException iae) {
+ } catch (final Exception iae) {
+ Assertions.fail("Should throw IllegalArgumentException");
+ }
+
+ try {
+ new DataClassWithValidation("ok name");
+ } catch (final Exception iae) {
+ Assertions.fail();
+ }
+ }
+
+ @Test
+ public void testBetterSetName_invalidName() {
+ Assertions.assertThrows(IllegalArgumentException.class, () -> new DataClassWithValidation(" name starting with blank"));
+ }
+
+ @Test
+ public void testBetterSetName_validName() {
+ new DataClassWithValidation("ok name");
+ }
+}
--
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