diff --git a/core-java/src/main/java/com/baeldung/initializationguide/User.java b/core-java/src/main/java/com/baeldung/initializationguide/User.java new file mode 100644 index 0000000000..e2e3f051dd --- /dev/null +++ b/core-java/src/main/java/com/baeldung/initializationguide/User.java @@ -0,0 +1,53 @@ +package com.baeldung.initializationguide; + +import java.io.Serializable; + +public class User implements Serializable, Cloneable { + private static final long serialVersionUID = 1L; + static String forum; + private String name; + private int id; + + { + id = 0; + System.out.println("Instance Initializer"); + } + + static { + forum = "Java"; + System.out.println("Static Initializer"); + } + + public User(String name, int id) { + super(); + this.name = name; + this.id = id; + } + + public User() { + System.out.println("Constructor"); + } + + public String getName() { + return name; + } + + public void setName(String name) { + this.name = name; + } + + public int getId() { + return id; + } + + public void setId(int id) { + this.id = id; + } + + @Override + protected Object clone() throws CloneNotSupportedException { + return this; + } + +} + diff --git a/core-java/src/test/java/com/baeldung/initializationguide/UserTest.java b/core-java/src/test/java/com/baeldung/initializationguide/UserTest.java new file mode 100644 index 0000000000..d0116d03b8 --- /dev/null +++ b/core-java/src/test/java/com/baeldung/initializationguide/UserTest.java @@ -0,0 +1,70 @@ +package com.baeldung.initializationguide; +import org.junit.Before; +import org.junit.Test; + +import static org.assertj.core.api.Assertions.*; + +import java.io.BufferedInputStream; +import java.io.BufferedOutputStream; +import java.io.FileInputStream; +import java.io.FileNotFoundException; +import java.io.FileOutputStream; +import java.io.IOException; +import java.io.ObjectInputStream; +import java.io.ObjectOutputStream; +import java.lang.reflect.InvocationTargetException; +import java.nio.file.Files; +import java.nio.file.Path; +import java.nio.file.Paths; + +public class UserTest { + + + Path userData; + + @Before + public void init() throws IOException { + userData = Paths.get("src/test/resources/user.data"); + if (!Files.exists(userData)) + Files.createFile(userData); + } + + @Test + public void givenUserInstance_whenIntializedWithNew_thenInstanceIsNotNull() { + User user = new User("Alice", 1); + assertThat(user).isNotNull(); + } + + @Test + public void givenUserInstance_whenInitializedWithReflection_thenInstanceIsNotNull() throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchMethodException, SecurityException { + User user = User.class.getConstructor(String.class, int.class) + .newInstance("Alice", 2); + assertThat(user).isNotNull(); + } + + @Test + public void givenUserInstance_whenCopiedWithClone_thenExactMatchIsCreated() throws CloneNotSupportedException { + User user = new User("Alice", 3); + User clonedUser = (User) user.clone(); + assertThat(clonedUser).isEqualTo(user); + } + + @Test + public void givenFileWithBitsRepresentingUser_whenDeserialized_thenUserIsCreated() throws FileNotFoundException, IOException, ClassNotFoundException { + try (ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(new FileOutputStream(userData.toFile())))) { + User user = new User("Tom", 0); + out.writeObject(user); + } + try (ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(new FileInputStream(userData.toFile())))) { + User deserializedUser = (User) in.readObject(); + assertThat(deserializedUser).isNotNull(); + } + } + + @Test + public void givenUserInstance_whenValuesAreNotInitialized_thenUserNameAndIdReturnDefault() { + User user = new User(); + assertThat(user.getName()).isNull(); + assertThat(user.getId() == 0); + } +} diff --git a/core-java/src/test/resources/user.data b/core-java/src/test/resources/user.data new file mode 100644 index 0000000000..e69de29bb2