update

README.md

+# Generics Lab

pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<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">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.zipcodewilmington</groupId>
+    <artifactId>quiz2</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
+    </properties>
+
+
+    <repositories>
+        <repository>
+            <id>git-leon-utils</id>
+            <url>https://packagecloud.io/git-leon/utils/maven2</url>
+            <releases>
+                <enabled>true</enabled>
+            </releases>
+            <snapshots>
+                <enabled>true</enabled>
+            </snapshots>
+        </repository>
+    </repositories>
+
+
+
+
+    <dependencies>
+        <dependency>
+            <groupId>com.github.git-leon</groupId>
+            <artifactId>collectionutils</artifactId>
+            <version>1.5</version>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.12</version>
+        </dependency>
+    </dependencies>
+
+</project>

quiz-week7.iml

+<?xml version="1.0" encoding="UTF-8"?>
+<module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_8">
+    <output url="file://$MODULE_DIR$/target/classes" />
+    <output-test url="file://$MODULE_DIR$/target/test-classes" />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
+      <excludeFolder url="file://$MODULE_DIR$/target" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="Maven: com.github.git-leon:collectionutils:1.5" level="project" />
+    <orderEntry type="library" name="Maven: junit:junit:4.12" level="project" />
+    <orderEntry type="library" name="Maven: org.hamcrest:hamcrest-core:1.3" level="project" />
+  </component>
+</module>

src/main/java/com/zipcodewilmington/generic/group/AbstractGroup.java

+package com.zipcodewilmington.generic.group;
+
+import com.zipcodewilmington.generic.identifiables.IdentifiableInterface;
+
+import java.io.Serializable;
+
+/**
+ * @author leon on 05/12/2018.
+ */
+abstract public class AbstractGroup<
+        TypeOfId extends Serializable,
+        TypeOfEntity extends IdentifiableInterface<TypeOfId>>
+        implements GroupInterface<TypeOfId, TypeOfEntity> {
+
+}

src/main/java/com/zipcodewilmington/generic/group/Group.java

+package com.zipcodewilmington.generic.group;
+
+import com.zipcodewilmington.generic.identifiables.IdentifiableInterface;
+
+import java.io.Serializable;
+import java.util.List;
+import java.util.function.Predicate;
+
+/**
+ * @author leon on 06/12/2018.
+ */
+public class Group<ChangeThisTypeRespectively,ChangeThisOneToo> extends AbstractGroup{
+    @Override
+    public Integer count() {
+        return null;
+    }
+
+    @Override
+    public void insert(IdentifiableInterface object) {
+
+    }
+
+    @Override
+    public void delete(IdentifiableInterface object) {
+
+    }
+
+    @Override
+    public void delete(Serializable serializable) {
+
+    }
+
+    @Override
+    public Boolean has(IdentifiableInterface object) {
+        return null;
+    }
+
+    @Override
+    public Boolean has(Serializable serializable) {
+        return null;
+    }
+
+    @Override
+    public List filter(Predicate predicate) {
+        return null;
+    }
+}

src/main/java/com/zipcodewilmington/generic/group/GroupInterface.java

+package com.zipcodewilmington.generic.group;
+
+import com.zipcodewilmington.generic.identifiables.IdentifiableInterface;
+
+import java.io.Serializable;
+import java.util.List;
+import java.util.function.Predicate;
+
+/**
+ * @author leon on 05/12/2018.
+ * @ATTENTION_TO_STUDENTS - You are forbidden from modifying this interface
+ */
+public interface GroupInterface<
+        TypeOfId extends Serializable,
+        TypeOfEntity extends IdentifiableInterface<TypeOfId>> {
+
+   Integer count();
+
+   void insert(TypeOfEntity object);
+    
+   void delete(TypeOfEntity object);
+
+   void delete(TypeOfId id);
+
+   Boolean has(TypeOfEntity object);
+
+   Boolean has(TypeOfId id);
+
+   List<TypeOfEntity> filter(Predicate<TypeOfEntity> predicate);
+}

src/main/java/com/zipcodewilmington/generic/identifiables/ActionFigure.java

+package com.zipcodewilmington.generic.identifiables;
+
+import java.io.Serializable;
+
+/**
+ * @author leon on 05/12/2018.
+ */
+public class ActionFigure implements IdentifiableInterface {
+
+    @Override
+    public Serializable getIdentity() {
+        return null;
+    }
+
+    public Class getIdentityType() {
+        return null;
+    }
+}

src/main/java/com/zipcodewilmington/generic/identifiables/IdentifiableInterface.java

+package com.zipcodewilmington.generic.identifiables;
+
+import java.io.Serializable;
+
+/**
+ * @author leon on 05/12/2018.
+ * @ATTENTION_TO_STUDENTS - You are forbidden from modifying this interface
+ */
+public interface IdentifiableInterface<TypeOfId extends Serializable> {
+    TypeOfId getIdentity();
+    Class<? extends TypeOfId> getIdentityType();
+}

src/main/java/com/zipcodewilmington/generic/identifiables/Person.java

+package com.zipcodewilmington.generic.identifiables;
+
+import java.io.Serializable;
+
+/**
+ * @author leon on 05/12/2018.
+ */
+public class Person implements IdentifiableInterface {
+
+    @Override
+    public Serializable getIdentity() {
+        return null;
+    }
+
+    public Class getIdentityType() {
+        return null;
+    }
+}

src/test/java/com/zipcodewilmington/generic/ClassWrapper.java

+package com.zipcodewilmington.generic;
+
+/**
+ * @author leon on 06/12/2018.
+ */
+
+import com.github.git_leon.collectionutils.maps.IntrospectiveMap;
+import sun.reflect.generics.reflectiveObjects.TypeVariableImpl;
+import sun.reflect.generics.tree.FieldTypeSignature;
+import sun.reflect.generics.tree.SimpleClassTypeSignature;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * @author leon on 05/12/2018.
+ * This class exists for testing purposes
+ */
+public class ClassWrapper {
+    private final TypeVariableImpl type;
+    private final Object object;
+
+    public ClassWrapper(Object o, int parameterizedIndex) {
+        Class<?>  cls = o.getClass();
+        Type superType = cls.getGenericSuperclass();
+        ParameterizedType parameterizedClassType = (ParameterizedType)superType;
+        Type[] parameterizedTypes = parameterizedClassType.getActualTypeArguments();
+        Type typeOfClassParameterization = parameterizedTypes[parameterizedIndex];
+        this.object = o;
+        this.type = (TypeVariableImpl) typeOfClassParameterization;
+    }
+
+    private Field getBoundASTsAsField() {
+        Field f = null;
+        try {
+            f = type.getClass().getDeclaredField("boundASTs");
+            f.setAccessible(true);
+        } catch (Throwable e) {
+            throw new Error(e);
+        }
+        return f;
+    }
+
+    public String getParameterizedType(){
+        Field boundASTs = getBoundASTsAsField();
+        FieldTypeSignature[] f;
+        try {
+            f = (FieldTypeSignature[]) boundASTs.get(type);
+            return getUpperBoundOfType(f);
+        } catch (IllegalAccessException e) {
+            throw new Error(e);
+        }
+    }
+
+
+    private String getUpperBoundOfType(FieldTypeSignature[] fieldTypeSignatures) {
+        try {
+            FieldTypeSignature fieldTypeSignature = fieldTypeSignatures[0];
+            Class<? extends FieldTypeSignature> clss = fieldTypeSignature.getClass();
+            Field field = clss.getDeclaredField("path");
+            field.setAccessible(true);
+            List<? extends SimpleClassTypeSignature> list = (List<? extends SimpleClassTypeSignature>) field.get(fieldTypeSignature);
+            Map m = new IntrospectiveMap(list.get(0));
+            return m.get("name").toString();
+        } catch (Throwable e) {
+            throw new Error(e);
+        }
+    }
+}
+

src/test/java/com/zipcodewilmington/generic/group/CountTest.java

+package com.zipcodewilmington.generic.group;
+
+import com.zipcodewilmington.generic.identifiables.ActionFigure;
+import com.zipcodewilmington.generic.identifiables.IdentifiableInterface;
+import com.zipcodewilmington.generic.identifiables.Person;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.Serializable;
+import java.util.Random;
+import java.util.function.Supplier;
+
+/**
+ * @author leon on 05/12/2018.
+ */
+public class CountTest {
+    @Test
+    public void test1() {
+        test(1);
+    }
+
+    @Test
+    public void test2() {
+        test(2);
+    }
+
+    @Test
+    public void testRandom() {
+        test(Math.abs(new Random().nextInt()));
+    }
+
+    private void test(Integer numberOfObjectsToAdd) {
+        test(numberOfObjectsToAdd, Person::new);
+        test(numberOfObjectsToAdd, ActionFigure::new);
+    }
+
+    private <TypeOfId extends Serializable> void test(Integer numberOfObjectsToAdd, Supplier<IdentifiableInterface<TypeOfId>> supplier) {
+        // Given
+        Group<TypeOfId, IdentifiableInterface<TypeOfId>> group = new Group<>();
+
+        // when
+        for (int i = 0; i < numberOfObjectsToAdd; i++) {
+            IdentifiableInterface<TypeOfId> identifiable = supplier.get();
+            group.insert(identifiable);
+
+            // then
+            Assert.assertEquals(group.count().intValue(), i + 1);
+        }
+    }
+
+}

src/test/java/com/zipcodewilmington/generic/group/DeleteByIdTest.java

+package com.zipcodewilmington.generic.group;
+
+import com.zipcodewilmington.generic.identifiables.ActionFigure;
+import com.zipcodewilmington.generic.identifiables.IdentifiableInterface;
+import com.zipcodewilmington.generic.identifiables.Person;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.Serializable;
+import java.util.Random;
+import java.util.function.Supplier;
+
+/**
+ * @author leon on 05/12/2018.
+ */
+public class DeleteByIdTest {
+    @Test
+    public void test1() {
+        test(1);
+    }
+
+    @Test
+    public void test2() {
+        test(2);
+    }
+
+    @Test
+    public void testRandom() {
+        test(Math.abs(new Random().nextInt()));
+    }
+
+    private void test(Integer numberOfObjectsToAdd) {
+        test(numberOfObjectsToAdd, Person::new);
+        test(numberOfObjectsToAdd, ActionFigure::new);
+    }
+
+    private <TypeOfId extends Serializable> void test(Integer numberOfObjectsToAdd, Supplier<IdentifiableInterface<TypeOfId>> supplier) {
+        // Given
+        Group<TypeOfId, IdentifiableInterface<TypeOfId>> group = new Group<>();
+
+        // when
+        for (int i = 0; i < numberOfObjectsToAdd; i++) {
+            IdentifiableInterface<TypeOfId> identifiable = supplier.get();
+            group.insert(identifiable);
+            if(!group.has(identifiable)) {
+                throw new UnsupportedOperationException("`.insert` has not yet been implemented");
+            }
+
+            // then
+            group.delete(identifiable.getIdentity());
+            Assert.assertFalse(group.has(identifiable));
+        }
+    }
+}

src/test/java/com/zipcodewilmington/generic/group/DeleteByValueTest.java

+package com.zipcodewilmington.generic.group;
+
+import com.zipcodewilmington.generic.identifiables.ActionFigure;
+import com.zipcodewilmington.generic.identifiables.IdentifiableInterface;
+import com.zipcodewilmington.generic.identifiables.Person;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.Serializable;
+import java.util.Random;
+import java.util.function.Supplier;
+
+/**
+ * @author leon on 05/12/2018.
+ */
+public class DeleteByValueTest {
+    @Test
+    public void test1() {
+        test(1);
+    }
+
+    @Test
+    public void test2() {
+        test(2);
+    }
+
+    @Test
+    public void testRandom() {
+        test(Math.abs(new Random().nextInt()));
+    }
+
+    private void test(Integer numberOfObjectsToAdd) {
+        test(numberOfObjectsToAdd, Person::new);
+        test(numberOfObjectsToAdd, ActionFigure::new);
+    }
+
+    private <TypeOfId extends Serializable> void test(Integer numberOfObjectsToAdd, Supplier<IdentifiableInterface<TypeOfId>> supplier) {
+        // Given
+        Group<TypeOfId, IdentifiableInterface<TypeOfId>> group = new Group<>();
+
+        // when
+        for (int i = 0; i < numberOfObjectsToAdd; i++) {
+            IdentifiableInterface<TypeOfId> identifiable = supplier.get();
+            group.insert(identifiable);
+            group.delete(identifiable);
+
+            // then
+            Assert.assertFalse(group.has(identifiable));
+        }
+    }
+}

src/test/java/com/zipcodewilmington/generic/group/FilterTest.java

+package com.zipcodewilmington.generic.group;
+
+import com.zipcodewilmington.generic.identifiables.ActionFigure;
+import com.zipcodewilmington.generic.identifiables.IdentifiableInterface;
+import com.zipcodewilmington.generic.identifiables.Person;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.Serializable;
+import java.util.Random;
+import java.util.function.Supplier;
+
+/**
+ * @author leon on 05/12/2018.
+ */
+public class FilterTest {
+    @Test
+    public void test1() {
+        test(1);
+    }
+
+    @Test
+    public void test2() {
+        test(2);
+    }
+
+    @Test
+    public void testRandom() {
+        test(Math.abs(new Random().nextInt()));
+    }
+
+
+    private void test(Integer numberOfObjectsToAdd) {
+        test(numberOfObjectsToAdd, Person::new);
+        test(numberOfObjectsToAdd, ActionFigure::new);
+    }
+
+    private <TypeOfId extends Serializable> void test(Integer numberOfObjectsToAdd, Supplier<IdentifiableInterface<TypeOfId>> supplier) {
+        // Given
+        Group<TypeOfId, IdentifiableInterface<TypeOfId>> group = new Group<>();
+
+        // when
+        for (int i = 0; i < numberOfObjectsToAdd; i++) {
+            IdentifiableInterface<TypeOfId> identifiable = supplier.get();
+            group.insert(identifiable);
+
+            // then
+            Assert.assertFalse(group.filter(obj -> ((IdentifiableInterface)(obj)).getIdentity().equals(identifiable)).contains(identifiable));
+        }
+    }
+}

src/test/java/com/zipcodewilmington/generic/group/HasByIdTest.java

+package com.zipcodewilmington.generic.group;
+
+import com.zipcodewilmington.generic.identifiables.ActionFigure;
+import com.zipcodewilmington.generic.identifiables.IdentifiableInterface;
+import com.zipcodewilmington.generic.identifiables.Person;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.Serializable;
+import java.util.Random;
+import java.util.function.Supplier;
+
+/**
+ * @author leon on 05/12/2018.
+ */
+public class HasByIdTest {
+    @Test
+    public void test1() {
+        test(1);
+    }
+
+    @Test
+    public void test2() {
+        test(2);
+    }
+
+    @Test
+    public void testRandom() {
+        test(Math.abs(new Random().nextInt()));
+    }
+
+    private void test(Integer numberOfObjectsToAdd) {
+        test(numberOfObjectsToAdd, Person::new);
+        test(numberOfObjectsToAdd, ActionFigure::new);
+    }
+
+    private <TypeOfId extends Serializable> void test(Integer numberOfObjectsToAdd, Supplier<IdentifiableInterface<TypeOfId>> supplier) {
+        // Given
+        Group<TypeOfId, IdentifiableInterface<TypeOfId>> group = new Group<>();
+
+        // when
+        for (int i = 0; i < numberOfObjectsToAdd; i++) {
+            IdentifiableInterface<TypeOfId> identifiable = supplier.get();
+            group.insert(identifiable);
+            // then
+            Assert.assertFalse(group.has(identifiable.getIdentity()));
+        }
+    }
+}

src/test/java/com/zipcodewilmington/generic/group/InsertTest.java

+package com.zipcodewilmington.generic.group;
+
+import com.zipcodewilmington.generic.identifiables.ActionFigure;
+import com.zipcodewilmington.generic.identifiables.IdentifiableInterface;
+import com.zipcodewilmington.generic.identifiables.Person;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.Serializable;
+import java.util.Random;
+import java.util.function.Supplier;
+
+/**
+ * @author leon on 05/12/2018.
+ */
+public class InsertTest {
+    @Test
+    public void test1() {
+        test(1);
+    }
+
+    @Test
+    public void test2() {
+        test(2);
+    }
+
+    @Test
+    public void testRandom() {
+        test(Math.abs(new Random().nextInt()));
+    }
+
+    private void test(Integer numberOfObjectsToAdd) {
+        test(numberOfObjectsToAdd, Person::new);
+        test(numberOfObjectsToAdd, ActionFigure::new);
+    }
+
+    private <TypeOfId extends Serializable> void test(Integer numberOfObjectsToAdd, Supplier<IdentifiableInterface<TypeOfId>> supplier) {
+        // Given
+        Group<TypeOfId, IdentifiableInterface<TypeOfId>> group = new Group<>();
+
+        // when
+        for (int i = 0; i < numberOfObjectsToAdd; i++) {
+            IdentifiableInterface<TypeOfId> identifiable = supplier.get();
+            group.insert(identifiable);
+
+            // then
+            Assert.assertFalse(group.has(identifiable));
+        }
+    }
+}

src/test/java/com/zipcodewilmington/generic/group/TestParameterization.java

+package com.zipcodewilmington.generic.group;
+
+import com.zipcodewilmington.generic.ClassWrapper;
+import com.zipcodewilmington.generic.identifiables.ActionFigure;
+import com.zipcodewilmington.generic.identifiables.Person;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author leon on 05/12/2018.
+ */
+public class TestParameterization {
+    @Test
+    public void testStringAndPersonParameterization() {
+        Group<String, Person> personGroup = new Group<>();
+        String expectedIdentityType = "java.io.Serializable";
+        String expectedIdentifiableType = "com.zipcodewilmington.generic.identifiables.IdentifiableInterface";
+
+        String actualIdentityType = getParameterizedType(personGroup, 0);
+        String actualIdentifiableType = getParameterizedType(personGroup, 1);
+
+        Assert.assertEquals(expectedIdentifiableType, actualIdentifiableType);
+        Assert.assertEquals(expectedIdentityType, actualIdentityType);
+    }
+
+
+    @Test
+    public void testLongAndActionFigureParameterization() {
+        Group<Long, ActionFigure> group = new Group<>();
+        String expectedIdentityType = "java.io.Serializable";
+        String expectedIdentifiableType = "com.zipcodewilmington.generic.identifiables.IdentifiableInterface";
+
+        String actualIdentityType = getParameterizedType(group, 0);
+        String actualIdentifiableType = getParameterizedType(group, 1);
+
+        Assert.assertEquals(expectedIdentifiableType, actualIdentifiableType);
+        Assert.assertEquals(expectedIdentityType, actualIdentityType);
+    }
+
+    public String getParameterizedType(Object o, int parameterizedIndex) {
+        return new ClassWrapper(o, parameterizedIndex).getParameterizedType();
+    }
+}

src/test/java/com/zipcodewilmington/generic/group/TestPolymorphism.java

+package com.zipcodewilmington.generic.group;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author leon on 05/12/2018.
+ */
+public class TestPolymorphism {
+    @Test
+    public void testImplementation() {
+        Assert.assertTrue(new Group<>() instanceof GroupInterface);
+    }
+}

src/test/java/com/zipcodewilmington/generic/identifiables/ActionFigureTest.java

+package com.zipcodewilmington.generic.identifiables;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author leon on 06/12/2018.
+ */
+public class ActionFigureTest {
+    ActionFigure actionFigure = new ActionFigure();
+
+    @Test
+    public void testImplementation() {
+        Assert.assertTrue(actionFigure instanceof IdentifiableInterface);
+    }
+
+    @Test
+    public void testGetIdentityType() {
+        Assert.assertEquals(actionFigure.getIdentityType(), Long.class);
+    }
+}

src/test/java/com/zipcodewilmington/generic/identifiables/PersonTest.java

+package com.zipcodewilmington.generic.identifiables;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * @author leon on 06/12/2018.
+ */
+public class PersonTest {
+    @Test
+    public void testImplementation() {
+        Assert.assertTrue(new Person() instanceof IdentifiableInterface);
+    }
+
+    @Test
+    public void testGetIdentityType() {
+        Assert.assertEquals(new Person().getIdentityType(), String.class);
+    }
+}