mindol1004/spring-boot-rest
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

2 - Second commit for articles:

Browse Source 
* to core-java-lang:
  * https://www.baeldung.com/java-inner-interfaces
  * https://www.baeldung.com/java-polymorphism
  * https://www.baeldung.com/java-recursion
  * https://www.baeldung.com/java-finalize
  * https://www.baeldung.com/java-method-overload-override
  * https://www.baeldung.com/java-deep-copy
  * https://www.baeldung.com/java-inheritance
  * https://www.baeldung.com/java-type-casting
  * https://www.baeldung.com/java-final
  * https://www.baeldung.com/a-guide-to-java-enums
This commit is contained in:
geroza
2018-11-10 00:37:39 -02:00
parent 792d6f6cc4
commit 64a22eec31
50 changed files with 0 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
core-java-lang/src/main/java/com/baeldung/casting/Animal.java Normal file
View File

@@ -0,0 +1,13 @@
package com.baeldung.casting;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class Animal {
private static final Logger LOGGER = LoggerFactory.getLogger(Animal.class);
public void eat() {
LOGGER.info("animal is eating");
}
}

23
core-java-lang/src/main/java/com/baeldung/casting/AnimalFeeder.java Normal file
View File

@@ -0,0 +1,23 @@
package com.baeldung.casting;
import java.util.List;
public class AnimalFeeder {
public void feed(List<Animal> animals) {
animals.forEach(animal -> {
animal.eat();
if (animal instanceof Cat) {
((Cat) animal).meow();
}
});
}
public void uncheckedFeed(List<Animal> animals) {
animals.forEach(animal -> {
animal.eat();
((Cat) animal).meow();
});
}
}

24
core-java-lang/src/main/java/com/baeldung/casting/AnimalFeederGeneric.java Normal file
View File

@@ -0,0 +1,24 @@
package com.baeldung.casting;
import java.util.ArrayList;
import java.util.List;
public class AnimalFeederGeneric<T> {
private Class<T> type;
public AnimalFeederGeneric(Class<T> type) {
this.type = type;
}
public List<T> feed(List<Animal> animals) {
List<T> list = new ArrayList<T>();
animals.forEach(animal -> {
if (type.isInstance(animal)) {
T objAsType = type.cast(animal);
list.add(objAsType);
}
});
return list;
}
}

16
core-java-lang/src/main/java/com/baeldung/casting/Cat.java Normal file
View File

@@ -0,0 +1,16 @@
package com.baeldung.casting;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class Cat extends Animal implements Mew {
private static final Logger LOGGER = LoggerFactory.getLogger(Cat.class);
public void eat() {
LOGGER.info("cat is eating");
}
public void meow() {
LOGGER.info("meow");
}
}

12
core-java-lang/src/main/java/com/baeldung/casting/Dog.java Normal file
View File

@@ -0,0 +1,12 @@
package com.baeldung.casting;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class Dog extends Animal {
private static final Logger LOGGER = LoggerFactory.getLogger(Dog.class);
public void eat() {
LOGGER.info("dog is eating");
}
}

5
core-java-lang/src/main/java/com/baeldung/casting/Mew.java Normal file
View File

@@ -0,0 +1,5 @@
package com.baeldung.casting;
public interface Mew {
public void meow();
}

59
core-java-lang/src/main/java/com/baeldung/deepcopy/Address.java Normal file
View File

@@ -0,0 +1,59 @@
package com.baeldung.deepcopy;
import java.io.Serializable;
public class Address implements Serializable, Cloneable {
@Override
public Object clone() {
try {
return (Address) super.clone();
} catch (CloneNotSupportedException e) {
return new Address(this.street, this.getCity(), this.getCountry());
}
}
private static final long serialVersionUID = 1740913841244949416L;
private String street;
private String city;
private String country;
public Address(Address that) {
this(that.getStreet(), that.getCity(), that.getCountry());
}
public Address(String street, String city, String country) {
this.street = street;
this.city = city;
this.country = country;
}
public Address() {
}
public String getStreet() {
return street;
}
public String getCity() {
return city;
}
public String getCountry() {
return country;
}
public void setStreet(String street) {
this.street = street;
}
public void setCity(String city) {
this.city = city;
}
public void setCountry(String country) {
this.country = country;
}
}

48
core-java-lang/src/main/java/com/baeldung/deepcopy/User.java Normal file
View File

@@ -0,0 +1,48 @@
package com.baeldung.deepcopy;
import java.io.Serializable;
public class User implements Serializable, Cloneable {
private static final long serialVersionUID = -3427002229954777557L;
private String firstName;
private String lastName;
private Address address;
public User(String firstName, String lastName, Address address) {
this.firstName = firstName;
this.lastName = lastName;
this.address = address;
}
public User(User that) {
this(that.getFirstName(), that.getLastName(), new Address(that.getAddress()));
}
public User() {
}
@Override
public Object clone() {
User user;
try {
user = (User) super.clone();
} catch (CloneNotSupportedException e) {
user = new User(this.getFirstName(), this.getLastName(), this.getAddress());
}
user.address = (Address) this.address.clone();
return user;
}
public String getFirstName() {
return firstName;
}
public String getLastName() {
return lastName;
}
public Address getAddress() {
return address;
}
}

88
core-java-lang/src/main/java/com/baeldung/enums/Pizza.java Normal file
View File

@@ -0,0 +1,88 @@
package com.baeldung.enums;
import java.util.EnumMap;
import java.util.EnumSet;
import java.util.List;
import java.util.stream.Collectors;
public class Pizza {
private static EnumSet<PizzaStatusEnum> deliveredPizzaStatuses = EnumSet.of(PizzaStatusEnum.DELIVERED);
private PizzaStatusEnum status;
public enum PizzaStatusEnum {
ORDERED(5) {
@Override
public boolean isOrdered() {
return true;
}
},
READY(2) {
@Override
public boolean isReady() {
return true;
}
},
DELIVERED(0) {
@Override
public boolean isDelivered() {
return true;
}
};
private int timeToDelivery;
public boolean isOrdered() {
return false;
}
public boolean isReady() {
return false;
}
public boolean isDelivered() {
return false;
}
public int getTimeToDelivery() {
return timeToDelivery;
}
PizzaStatusEnum(int timeToDelivery) {
this.timeToDelivery = timeToDelivery;
}
}
public PizzaStatusEnum getStatus() {
return status;
}
public void setStatus(PizzaStatusEnum status) {
this.status = status;
}
public boolean isDeliverable() {
return this.status.isReady();
}
public void printTimeToDeliver() {
System.out.println("Time to delivery is " + this.getStatus().getTimeToDelivery() + " days");
}
public static List<Pizza> getAllUndeliveredPizzas(List<Pizza> input) {
return input.stream().filter((s) -> !deliveredPizzaStatuses.contains(s.getStatus())).collect(Collectors.toList());
}
public static EnumMap<PizzaStatusEnum, List<Pizza>> groupPizzaByStatus(List<Pizza> pzList) {
return pzList.stream().collect(Collectors.groupingBy(Pizza::getStatus, () -> new EnumMap<>(PizzaStatusEnum.class), Collectors.toList()));
}
public void deliver() {
if (isDeliverable()) {
PizzaDeliverySystemConfiguration.getInstance().getDeliveryStrategy().deliver(this);
this.setStatus(PizzaStatusEnum.DELIVERED);
}
}
}

18
core-java-lang/src/main/java/com/baeldung/enums/PizzaDeliveryStrategy.java Normal file
View File

@@ -0,0 +1,18 @@
package com.baeldung.enums;
public enum PizzaDeliveryStrategy {
EXPRESS {
@Override
public void deliver(Pizza pz) {
System.out.println("Pizza will be delivered in express mode");
}
},
NORMAL {
@Override
public void deliver(Pizza pz) {
System.out.println("Pizza will be delivered in normal mode");
}
};
public abstract void deliver(Pizza pz);
}

21
core-java-lang/src/main/java/com/baeldung/enums/PizzaDeliverySystemConfiguration.java Normal file
View File

@@ -0,0 +1,21 @@
package com.baeldung.enums;
public enum PizzaDeliverySystemConfiguration {
INSTANCE;
PizzaDeliverySystemConfiguration() {
// Do the configuration initialization which
// involves overriding defaults like delivery strategy
}
private PizzaDeliveryStrategy deliveryStrategy = PizzaDeliveryStrategy.NORMAL;
public static PizzaDeliverySystemConfiguration getInstance() {
return INSTANCE;
}
public PizzaDeliveryStrategy getDeliveryStrategy() {
return deliveryStrategy;
}
}

2
core-java-lang/src/main/java/com/baeldung/enums/README.md Normal file
View File

@@ -0,0 +1,2 @@
### Relevant Articles:
- [A Guide to Java Enums](http://www.baeldung.com/a-guide-to-java-enums)

30
core-java-lang/src/main/java/com/baeldung/finalize/CloseableResource.java Normal file
View File

@@ -0,0 +1,30 @@
package com.baeldung.finalize;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
public class CloseableResource implements AutoCloseable {
private BufferedReader reader;
public CloseableResource() {
InputStream input = this.getClass().getClassLoader().getResourceAsStream("file.txt");
reader = new BufferedReader(new InputStreamReader(input));
}
public String readFirstLine() throws IOException {
String firstLine = reader.readLine();
return firstLine;
}
@Override
public void close() {
try {
reader.close();
System.out.println("Closed BufferedReader in the close method");
} catch (IOException e) {
e.printStackTrace();
}
}
}

30
core-java-lang/src/main/java/com/baeldung/finalize/Finalizable.java Normal file
View File

@@ -0,0 +1,30 @@
package com.baeldung.finalize;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
public class Finalizable {
private BufferedReader reader;
public Finalizable() {
InputStream input = this.getClass().getClassLoader().getResourceAsStream("file.txt");
reader = new BufferedReader(new InputStreamReader(input));
}
public String readFirstLine() throws IOException {
String firstLine = reader.readLine();
return firstLine;
}
@Override
public void finalize() {
try {
reader.close();
System.out.println("Closed BufferedReader in the finalizer");
} catch (IOException e) {
e.printStackTrace();
}
}
}

5
core-java-lang/src/main/java/com/baeldung/finalkeyword/BlackCat.java Normal file
View File

@@ -0,0 +1,5 @@
package com.baeldung.finalkeyword;
public class BlackCat {
}

6
core-java-lang/src/main/java/com/baeldung/finalkeyword/BlackDog.java Normal file
View File

@@ -0,0 +1,6 @@
package com.baeldung.finalkeyword;
public class BlackDog extends Dog {
// public void sound() {
// }
}

18
core-java-lang/src/main/java/com/baeldung/finalkeyword/Cat.java Normal file
View File

@@ -0,0 +1,18 @@
package com.baeldung.finalkeyword;
public final class Cat {
private int weight;
public int getWeight() {
return weight;
}
public void setWeight(int weight) {
this.weight = weight;
}
public void methodWithFinalArguments(final int x) {
// x=1;
}
}

7
core-java-lang/src/main/java/com/baeldung/finalkeyword/Dog.java Normal file
View File

@@ -0,0 +1,7 @@
package com.baeldung.finalkeyword;
public class Dog {
public final void sound() {
}
}

43
core-java-lang/src/main/java/com/baeldung/inheritance/ArmoredCar.java Normal file
View File

@@ -0,0 +1,43 @@
package com.baeldung.inheritance;
public class ArmoredCar extends Car implements Floatable, Flyable{
private int bulletProofWindows;
private String model;
public void remoteStartCar() {
// this vehicle can be started by using a remote control
}
public String registerModel() {
return model;
}
public String getAValue() {
return super.model; // returns value of model defined in base class Car
// return this.model; // will return value of model defined in ArmoredCar
// return model; // will return value of model defined in ArmoredCar
}
public static String msg() {
// return super.msg(); // this won't compile.
return "ArmoredCar";
}
@Override
public void floatOnWater() {
System.out.println("I can float!");
}
@Override
public void fly() {
System.out.println("I can fly!");
}
public void aMethod() {
// System.out.println(duration); // Won't compile
System.out.println(Floatable.duration); // outputs 10
System.out.println(Flyable.duration); // outputs 20
}
}

12
core-java-lang/src/main/java/com/baeldung/inheritance/BMW.java Normal file
View File

@@ -0,0 +1,12 @@
package com.baeldung.inheritance;
public class BMW extends Car {
public BMW() {
super(5, "BMW");
}
@Override
public String toString() {
return model;
}
}

32
core-java-lang/src/main/java/com/baeldung/inheritance/Car.java Normal file
View File

@@ -0,0 +1,32 @@
package com.baeldung.inheritance;
public class Car {
private final int DEFAULT_WHEEL_COUNT = 5;
private final String DEFAULT_MODEL = "Basic";
protected int wheels;
protected String model;
public Car() {
this.wheels = DEFAULT_WHEEL_COUNT;
this.model = DEFAULT_MODEL;
}
public Car(int wheels, String model) {
this.wheels = wheels;
this.model = model;
}
public void start() {
// Check essential parts
// If okay, start.
}
public static int count = 10;
public static String msg() {
return "Car";
}
public String toString() {
return model;
}
}

15
core-java-lang/src/main/java/com/baeldung/inheritance/Employee.java Normal file
View File

@@ -0,0 +1,15 @@
package com.baeldung.inheritance;
public class Employee {
private String name;
private Car car;
public Employee(String name, Car car) {
this.name = name;
this.car = car;
}
public Car getCar() {
return car;
}
}

10
core-java-lang/src/main/java/com/baeldung/inheritance/Floatable.java Normal file
View File

@@ -0,0 +1,10 @@
package com.baeldung.inheritance;
public interface Floatable {
int duration = 10;
void floatOnWater();
default void repair() {
System.out.println("Repairing Floatable object");
}
}

13
core-java-lang/src/main/java/com/baeldung/inheritance/Flyable.java Normal file
View File

@@ -0,0 +1,13 @@
package com.baeldung.inheritance;
public interface Flyable {
int duration = 10;
void fly();
/*
* Commented
*/
//default void repair() {
// System.out.println("Repairing Flyable object");
//}
}

18
core-java-lang/src/main/java/com/baeldung/inheritance/SpaceCar.java Normal file
View File

@@ -0,0 +1,18 @@
package com.baeldung.inheritance;
public class SpaceCar extends Car implements SpaceTraveller {
@Override
public void floatOnWater() {
System.out.println("SpaceCar floating!");
}
@Override
public void fly() {
System.out.println("SpaceCar flying!");
}
@Override
public void remoteControl() {
System.out.println("SpaceCar being controlled remotely!");
}
}

6
core-java-lang/src/main/java/com/baeldung/inheritance/SpaceTraveller.java Normal file
View File

@@ -0,0 +1,6 @@
package com.baeldung.inheritance;
public interface SpaceTraveller extends Floatable, Flyable {
int duration = 10;
void remoteControl();
}

21
core-java-lang/src/main/java/com/baeldung/interfaces/CommaSeparatedCustomers.java Normal file
View File

@@ -0,0 +1,21 @@
package com.baeldung.interfaces;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
public class CommaSeparatedCustomers implements Customer.List {
private List<Customer> customers = new ArrayList<Customer>();
@Override
public void Add(Customer customer) {
customers.add(customer);
}
@Override
public String getCustomerNames() {
return customers.stream().map(customer -> customer.getName()).collect(Collectors.joining(","));
}
}

19
core-java-lang/src/main/java/com/baeldung/interfaces/Customer.java Normal file
View File

@@ -0,0 +1,19 @@
package com.baeldung.interfaces;
public class Customer {
public interface List {
void Add(Customer customer);
String getCustomerNames();
}
private String name;
public Customer(String name) {
this.name = name;
}
String getName() {
return name;
}
}

26
core-java-lang/src/main/java/com/baeldung/methodoverloadingoverriding/application/Application.java Normal file
View File

@@ -0,0 +1,26 @@
package com.baeldung.methodoverloadingoverriding.application;
import com.baeldung.methodoverloadingoverriding.model.Car;
import com.baeldung.methodoverloadingoverriding.model.Vehicle;
import com.baeldung.methodoverloadingoverriding.util.Multiplier;
public class Application {
public static void main(String[] args) {
Multiplier multiplier = new Multiplier();
System.out.println(multiplier.multiply(10, 10));
System.out.println(multiplier.multiply(10, 10, 10));
System.out.println(multiplier.multiply(10, 10.5));
System.out.println(multiplier.multiply(10.5, 10.5));
Vehicle vehicle = new Vehicle();
System.out.println(vehicle.accelerate(100));
System.out.println(vehicle.run());
System.out.println(vehicle.stop());
Vehicle car = new Car();
System.out.println(car.accelerate(80));
System.out.println(car.run());
System.out.println(car.stop());
}
}

9
core-java-lang/src/main/java/com/baeldung/methodoverloadingoverriding/model/Car.java Normal file
View File

@@ -0,0 +1,9 @@
package com.baeldung.methodoverloadingoverriding.model;
public class Car extends Vehicle {
@Override
public String accelerate(long mph) {
return "The car accelerates at : " + mph + " MPH.";
}
}

16
core-java-lang/src/main/java/com/baeldung/methodoverloadingoverriding/model/Vehicle.java Normal file
View File

@@ -0,0 +1,16 @@
package com.baeldung.methodoverloadingoverriding.model;
public class Vehicle {
public String accelerate(long mph) {
return "The vehicle accelerates at : " + mph + " MPH.";
}
public String stop() {
return "The vehicle has stopped.";
}
public String run() {
return "The vehicle is running.";
}
}

16
core-java-lang/src/main/java/com/baeldung/methodoverloadingoverriding/util/Multiplier.java Normal file
View File

@@ -0,0 +1,16 @@
package com.baeldung.methodoverloadingoverriding.util;
public class Multiplier {
public int multiply(int a, int b) {
return a * b;
}
public int multiply(int a, int b, int c) {
return a * b * c;
}
public double multiply(double a, double b) {
return a * b;
}
}

38
core-java-lang/src/main/java/com/baeldung/polymorphism/FileManager.java Normal file
View File

@@ -0,0 +1,38 @@
package com.baeldung.polymorphism;
import java.awt.image.BufferedImage;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class FileManager {
final static Logger logger = LoggerFactory.getLogger(FileManager.class);
public static void main(String[] args) {
GenericFile file1 = new TextFile("SampleTextFile", "This is a sample text content", "v1.0.0");
logger.info("File Info: \n" + file1.getFileInfo() + "\n");
ImageFile imageFile = new ImageFile("SampleImageFile", 200, 100, new BufferedImage(100, 200, BufferedImage.TYPE_INT_RGB).toString()
.getBytes(), "v1.0.0");
logger.info("File Info: \n" + imageFile.getFileInfo());
}
public static ImageFile createImageFile(String name, int height, int width, byte[] content, String version) {
ImageFile imageFile = new ImageFile(name, height, width, content, version);
logger.info("File 2 Info: \n" + imageFile.getFileInfo());
return imageFile;
}
public static GenericFile createTextFile(String name, String content, String version) {
GenericFile file1 = new TextFile(name, content, version);
logger.info("File 1 Info: \n" + file1.getFileInfo() + "\n");
return file1;
}
public static TextFile createTextFile2(String name, String content, String version) {
TextFile file1 = new TextFile(name, content, version);
logger.info("File 1 Info: \n" + file1.getFileInfo() + "\n");
return file1;
}
}

63
core-java-lang/src/main/java/com/baeldung/polymorphism/GenericFile.java Normal file
View File

@@ -0,0 +1,63 @@
package com.baeldung.polymorphism;
import java.util.Date;
public class GenericFile {
private String name;
private String extension;
private Date dateCreated;
private String version;
private byte[] content;
public GenericFile() {
this.setDateCreated(new Date());
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getExtension() {
return extension;
}
public void setExtension(String extension) {
this.extension = extension;
}
public Date getDateCreated() {
return dateCreated;
}
public void setDateCreated(Date dateCreated) {
this.dateCreated = dateCreated;
}
public String getVersion() {
return version;
}
public void setVersion(String version) {
this.version = version;
}
public byte[] getContent() {
return content;
}
public void setContent(byte[] content) {
this.content = content;
}
public String getFileInfo() {
return "Generic File Impl";
}
public Object read() {
return content;
}
}

41
core-java-lang/src/main/java/com/baeldung/polymorphism/ImageFile.java Normal file
View File

@@ -0,0 +1,41 @@
package com.baeldung.polymorphism;
public class ImageFile extends GenericFile {
private int height;
private int width;
public ImageFile(String name, int height, int width, byte[] content, String version) {
this.setHeight(height);
this.setWidth(width);
this.setContent(content);
this.setName(name);
this.setVersion(version);
this.setExtension(".jpg");
}
public int getHeight() {
return height;
}
public void setHeight(int height) {
this.height = height;
}
public int getWidth() {
return width;
}
public void setWidth(int width) {
this.width = width;
}
public String getFileInfo() {
return "Image File Impl";
}
public String read() {
return this.getContent()
.toString();
}
}

44
core-java-lang/src/main/java/com/baeldung/polymorphism/TextFile.java Normal file
View File

@@ -0,0 +1,44 @@
package com.baeldung.polymorphism;
public class TextFile extends GenericFile {
private int wordCount;
public TextFile(String name, String content, String version) {
String[] words = content.split(" ");
this.setWordCount(words.length > 0 ? words.length : 1);
this.setContent(content.getBytes());
this.setName(name);
this.setVersion(version);
this.setExtension(".txt");
}
public int getWordCount() {
return wordCount;
}
public void setWordCount(int wordCount) {
this.wordCount = wordCount;
}
public String getFileInfo() {
return "Text File Impl";
}
public String read() {
return this.getContent()
.toString();
}
public String read(int limit) {
return this.getContent()
.toString()
.substring(0, limit);
}
public String read(int start, int stop) {
return this.getContent()
.toString()
.substring(start, stop);
}
}

31
core-java-lang/src/main/java/com/baeldung/recursion/BinaryNode.java Normal file
View File

@@ -0,0 +1,31 @@
package com.baeldung.recursion;
public class BinaryNode {
int value;
BinaryNode left;
BinaryNode right;
public BinaryNode(int value){
this.value = value;
}
public int getValue() {
return value;
}
public void setValue(int value) {
this.value = value;
}
public BinaryNode getLeft() {
return left;
}
public void setLeft(BinaryNode left) {
this.left = left;
}
public BinaryNode getRight() {
return right;
}
public void setRight(BinaryNode right) {
this.right = right;
}
}

64
core-java-lang/src/main/java/com/baeldung/recursion/RecursionExample.java Normal file
View File

@@ -0,0 +1,64 @@
package com.baeldung.recursion;
public class RecursionExample {
public int sum(int n){
if (n >= 1){
return sum(n - 1) + n;
}
return n;
}
public int tailSum(int currentSum, int n){
if (n <= 1) {
return currentSum + n;
}
return tailSum(currentSum + n, n - 1);
}
public int iterativeSum(int n){
int sum = 0;
if(n < 0){
return -1;
}
for(int i=0; i<=n; i++){
sum += i;
}
return sum;
}
public int powerOf10(int n){
if (n == 0){
return 1;
}
return powerOf10(n-1)*10;
}
public int fibonacci(int n){
if (n <=1 ){
return n;
}
return fibonacci(n-1) + fibonacci(n-2);
}
public String toBinary(int n){
if (n <= 1 ){
return String.valueOf(n);
}
return toBinary(n / 2) + String.valueOf(n % 2);
}
public int calculateTreeHeight(BinaryNode root){
if (root!= null){
if (root.getLeft() != null || root.getRight() != null){
return 1 + max(calculateTreeHeight(root.left) , calculateTreeHeight(root.right));
}
}
return 0;
}
public int max(int a,int b){
return a>b ? a:b;
}
}

80
core-java-lang/src/test/java/com/baeldung/casting/CastingUnitTest.java Normal file
View File

@@ -0,0 +1,80 @@
package com.baeldung.casting;
import org.junit.Test;
import static org.junit.Assert.*;
import java.util.ArrayList;
import java.util.List;
public class CastingUnitTest {
@Test
public void whenPrimitiveConverted_thenValueChanged() {
double myDouble = 1.1;
int myInt = (int) myDouble;
assertNotEquals(myDouble, myInt);
}
@Test
public void whenUpcast_thenInstanceUnchanged() {
Cat cat = new Cat();
Animal animal = cat;
animal = (Animal) cat;
assertTrue(animal instanceof Cat);
}
@Test
public void whenUpcastToObject_thenInstanceUnchanged() {
Object object = new Animal();
assertTrue(object instanceof Animal);
}
@Test
public void whenUpcastToInterface_thenInstanceUnchanged() {
Mew mew = new Cat();
assertTrue(mew instanceof Cat);
}
@Test
public void whenUpcastToAnimal_thenOverridenMethodsCalled() {
List<Animal> animals = new ArrayList<>();
animals.add(new Cat());
animals.add(new Dog());
new AnimalFeeder().feed(animals);
}
@Test
public void whenDowncastToCat_thenMeowIsCalled() {
Animal animal = new Cat();
((Cat) animal).meow();
}
@Test(expected = ClassCastException.class)
public void whenDownCastWithoutCheck_thenExceptionThrown() {
List<Animal> animals = new ArrayList<>();
animals.add(new Cat());
animals.add(new Dog());
new AnimalFeeder().uncheckedFeed(animals);
}
@Test
public void whenDowncastToCatWithCastMethod_thenMeowIsCalled() {
Animal animal = new Cat();
if (Cat.class.isInstance(animal)) {
Cat cat = Cat.class.cast(animal);
cat.meow();
}
}
@Test
public void whenParameterCat_thenOnlyCatsFed() {
List<Animal> animals = new ArrayList<>();
animals.add(new Cat());
animals.add(new Dog());
AnimalFeederGeneric<Cat> catFeeder = new AnimalFeederGeneric<Cat>(Cat.class);
List<Cat> fedAnimals = catFeeder.feed(animals);
assertTrue(fedAnimals.size() == 1);
assertTrue(fedAnimals.get(0) instanceof Cat);
}
}

128
core-java-lang/src/test/java/com/baeldung/deepcopy/DeepCopyUnitTest.java Normal file
View File

@@ -0,0 +1,128 @@
package com.baeldung.deepcopy;
import static org.assertj.core.api.Assertions.assertThat;
import java.io.IOException;
import org.apache.commons.lang.SerializationUtils;
import org.junit.Ignore;
import org.junit.Test;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.gson.Gson;
public class DeepCopyUnitTest {
@Test
public void whenCreatingDeepCopyWithCopyConstructor_thenObjectsShouldNotBeSame() {
Address address = new Address("Downing St 10", "London", "England");
User pm = new User("Prime", "Minister", address);
User deepCopy = new User(pm);
assertThat(deepCopy).isNotSameAs(pm);
}
@Test
public void whenModifyingOriginalObject_thenConstructorCopyShouldNotChange() {
Address address = new Address("Downing St 10", "London", "England");
User pm = new User("Prime", "Minister", address);
User deepCopy = new User(pm);
address.setCountry("Great Britain");
assertThat(deepCopy.getAddress().getCountry()).isNotEqualTo(pm.getAddress().getCountry());
}
@Test
public void whenModifyingOriginalObject_thenCloneCopyShouldNotChange() {
Address address = new Address("Downing St 10", "London", "England");
User pm = new User("Prime", "Minister", address);
User deepCopy = (User) pm.clone();
address.setCountry("Great Britain");
assertThat(deepCopy.getAddress().getCountry()).isNotEqualTo(pm.getAddress().getCountry());
}
@Test
public void whenModifyingOriginalObject_thenCommonsCloneShouldNotChange() {
Address address = new Address("Downing St 10", "London", "England");
User pm = new User("Prime", "Minister", address);
User deepCopy = (User) SerializationUtils.clone(pm);
address.setCountry("Great Britain");
assertThat(deepCopy.getAddress().getCountry()).isNotEqualTo(pm.getAddress().getCountry());
}
@Test
public void whenModifyingOriginalObject_thenGsonCloneShouldNotChange() {
Address address = new Address("Downing St 10", "London", "England");
User pm = new User("Prime", "Minister", address);
Gson gson = new Gson();
User deepCopy = gson.fromJson(gson.toJson(pm), User.class);
address.setCountry("Great Britain");
assertThat(deepCopy.getAddress().getCountry()).isNotEqualTo(pm.getAddress().getCountry());
}
@Test
public void whenModifyingOriginalObject_thenJacksonCopyShouldNotChange() throws IOException {
Address address = new Address("Downing St 10", "London", "England");
User pm = new User("Prime", "Minister", address);
ObjectMapper objectMapper = new ObjectMapper();
User deepCopy = objectMapper.readValue(objectMapper.writeValueAsString(pm), User.class);
address.setCountry("Great Britain");
assertThat(deepCopy.getAddress().getCountry()).isNotEqualTo(pm.getAddress().getCountry());
}
@Test
@Ignore
public void whenMakingCopies_thenShowHowLongEachMethodTakes() throws CloneNotSupportedException, IOException {
int times = 1000000;
Address address = new Address("Downing St 10", "London", "England");
User pm = new User("Prime", "Minister", address);
long start = System.currentTimeMillis();
for (int i = 0; i < times; i++) {
User primeMinisterClone = (User) SerializationUtils.clone(pm);
}
long end = System.currentTimeMillis();
System.out.println("Cloning with Apache Commons Lang took " + (end - start) + " milliseconds.");
start = System.currentTimeMillis();
Gson gson = new Gson();
for (int i = 0; i < times; i++) {
User primeMinisterClone = gson.fromJson(gson.toJson(pm), User.class);
}
end = System.currentTimeMillis();
System.out.println("Cloning with Gson took " + (end - start) + " milliseconds.");
start = System.currentTimeMillis();
for (int i = 0; i < times; i++) {
User primeMinisterClone = new User(pm);
}
end = System.currentTimeMillis();
System.out.println("Cloning with the copy constructor took " + (end - start) + " milliseconds.");
start = System.currentTimeMillis();
for (int i = 0; i < times; i++) {
User primeMinisterClone = (User) pm.clone();
}
end = System.currentTimeMillis();
System.out.println("Cloning with Cloneable interface took " + (end - start) + " milliseconds.");
start = System.currentTimeMillis();
ObjectMapper objectMapper = new ObjectMapper();
for (int i = 0; i < times; i++) {
User primeMinisterClone = objectMapper.readValue(objectMapper.writeValueAsString(pm), User.class);
}
end = System.currentTimeMillis();
System.out.println("Cloning with Jackson took " + (end - start) + " milliseconds.");
}
}

33
core-java-lang/src/test/java/com/baeldung/deepcopy/ShallowCopyUnitTest.java Normal file
View File

@@ -0,0 +1,33 @@
package com.baeldung.deepcopy;
import static org.assertj.core.api.Assertions.assertThat;
import org.junit.Test;
public class ShallowCopyUnitTest {
@Test
public void whenShallowCopying_thenObjectsShouldNotBeSame() {
Address address = new Address("Downing St 10", "London", "England");
User pm = new User("Prime", "Minister", address);
User shallowCopy = new User(pm.getFirstName(), pm.getLastName(), pm.getAddress());
assertThat(shallowCopy)
.isNotSameAs(pm);
}
@Test
public void whenModifyingOriginalObject_thenCopyShouldChange() {
Address address = new Address("Downing St 10", "London", "England");
User pm = new User("Prime", "Minister", address);
User shallowCopy = new User(pm.getFirstName(), pm.getLastName(), pm.getAddress());
address.setCountry("Great Britain");
assertThat(shallowCopy.getAddress().getCountry())
.isEqualTo(pm.getAddress().getCountry());
}
}

79
core-java-lang/src/test/java/com/baeldung/enums/PizzaUnitTest.java Normal file
View File

@@ -0,0 +1,79 @@
package com.baeldung.enums;
import com.baeldung.enums.Pizza.PizzaStatusEnum;
import org.junit.Test;
import java.util.ArrayList;
import java.util.EnumMap;
import java.util.List;
import static junit.framework.TestCase.assertTrue;
public class PizzaUnitTest {
@Test
public void givenPizaOrder_whenReady_thenDeliverable() {
Pizza testPz = new Pizza();
testPz.setStatus(Pizza.PizzaStatusEnum.READY);
assertTrue(testPz.isDeliverable());
}
@Test
public void givenPizaOrders_whenRetrievingUnDeliveredPzs_thenCorrectlyRetrieved() {
List<Pizza> pzList = new ArrayList<>();
Pizza pz1 = new Pizza();
pz1.setStatus(Pizza.PizzaStatusEnum.DELIVERED);
Pizza pz2 = new Pizza();
pz2.setStatus(Pizza.PizzaStatusEnum.ORDERED);
Pizza pz3 = new Pizza();
pz3.setStatus(Pizza.PizzaStatusEnum.ORDERED);
Pizza pz4 = new Pizza();
pz4.setStatus(Pizza.PizzaStatusEnum.READY);
pzList.add(pz1);
pzList.add(pz2);
pzList.add(pz3);
pzList.add(pz4);
List<Pizza> undeliveredPzs = Pizza.getAllUndeliveredPizzas(pzList);
assertTrue(undeliveredPzs.size() == 3);
}
@Test
public void givenPizaOrders_whenGroupByStatusCalled_thenCorrectlyGrouped() {
List<Pizza> pzList = new ArrayList<>();
Pizza pz1 = new Pizza();
pz1.setStatus(Pizza.PizzaStatusEnum.DELIVERED);
Pizza pz2 = new Pizza();
pz2.setStatus(Pizza.PizzaStatusEnum.ORDERED);
Pizza pz3 = new Pizza();
pz3.setStatus(Pizza.PizzaStatusEnum.ORDERED);
Pizza pz4 = new Pizza();
pz4.setStatus(Pizza.PizzaStatusEnum.READY);
pzList.add(pz1);
pzList.add(pz2);
pzList.add(pz3);
pzList.add(pz4);
EnumMap<Pizza.PizzaStatusEnum, List<Pizza>> map = Pizza.groupPizzaByStatus(pzList);
assertTrue(map.get(Pizza.PizzaStatusEnum.DELIVERED).size() == 1);
assertTrue(map.get(Pizza.PizzaStatusEnum.ORDERED).size() == 2);
assertTrue(map.get(Pizza.PizzaStatusEnum.READY).size() == 1);
}
@Test
public void whenDelivered_thenPizzaGetsDeliveredAndStatusChanges() {
Pizza pz = new Pizza();
pz.setStatus(Pizza.PizzaStatusEnum.READY);
pz.deliver();
assertTrue(pz.getStatus() == Pizza.PizzaStatusEnum.DELIVERED);
}
}

23
core-java-lang/src/test/java/com/baeldung/finalize/FinalizeUnitTest.java Normal file
View File

@@ -0,0 +1,23 @@
package com.baeldung.finalize;
import java.io.IOException;
import org.junit.Assert;
import org.junit.Test;
public class FinalizeUnitTest {
@Test
public void whenGC_thenFinalizerExecuted() throws IOException {
String firstLine = new Finalizable().readFirstLine();
Assert.assertEquals("baeldung.com", firstLine);
System.gc();
}
@Test
public void whenTryWResourcesExits_thenResourceClosed() throws IOException {
try (CloseableResource resource = new CloseableResource()) {
String firstLine = resource.readFirstLine();
Assert.assertEquals("baeldung.com", firstLine);
}
}
}

33
core-java-lang/src/test/java/com/baeldung/finalkeyword/FinalUnitTest.java Normal file
View File

@@ -0,0 +1,33 @@
package com.baeldung.finalkeyword;
import org.junit.Test;
import static org.junit.Assert.*;
public class FinalUnitTest {
@Test
public void whenChangedFinalClassProperties_thenChanged() {
Cat cat = new Cat();
cat.setWeight(1);
assertEquals(1, cat.getWeight());
}
@Test
public void whenFinalVariableAssign_thenOnlyOnce() {
final int i;
i = 1;
// i=2;
}
@Test
public void whenChangedFinalReference_thenChanged() {
final Cat cat = new Cat();
// cat=new Cat();
cat.setWeight(5);
assertEquals(5, cat.getWeight());
}
}

46
core-java-lang/src/test/java/com/baeldung/inheritance/AppUnitTest.java Normal file
View File

@@ -0,0 +1,46 @@
package com.baeldung.inheritance;
import com.baeldung.inheritance.*;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
public class AppUnitTest extends TestCase {
public AppUnitTest(String testName) {
super( testName );
}
public static Test suite() {
return new TestSuite(AppUnitTest.class);
}
@SuppressWarnings("static-access")
public void testStaticMethodUsingBaseClassVariable() {
Car first = new ArmoredCar();
assertEquals("Car", first.msg());
}
@SuppressWarnings("static-access")
public void testStaticMethodUsingDerivedClassVariable() {
ArmoredCar second = new ArmoredCar();
assertEquals("ArmoredCar", second.msg());
}
public void testAssignArmoredCarToCar() {
Employee e1 = new Employee("Shreya", new ArmoredCar());
assertNotNull(e1.getCar());
}
public void testAssignSpaceCarToCar() {
Employee e2 = new Employee("Paul", new SpaceCar());
assertNotNull(e2.getCar());
}
public void testBMWToCar() {
Employee e3 = new Employee("Pavni", new BMW());
assertNotNull(e3.getCar());
}
}

18
core-java-lang/src/test/java/com/baeldung/interfaces/InnerInterfaceUnitTest.java Normal file
View File

@@ -0,0 +1,18 @@
package com.baeldung.interfaces;
import static org.junit.Assert.assertEquals;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
@RunWith(JUnit4.class)
public class InnerInterfaceUnitTest {
@Test
public void whenCustomerListJoined_thenReturnsJoinedNames() {
Customer.List customerList = new CommaSeparatedCustomers();
customerList.Add(new Customer("customer1"));
customerList.Add(new Customer("customer2"));
assertEquals("customer1,customer2", customerList.getCustomerNames());
}
}

41
core-java-lang/src/test/java/com/baeldung/methodoverloadingoverriding/test/MethodOverloadingUnitTest.java Normal file
View File

@@ -0,0 +1,41 @@
package com.baeldung.methodoverloadingoverriding.test;
import com.baeldung.methodoverloadingoverriding.util.Multiplier;
import org.junit.BeforeClass;
import org.junit.Test;
import static org.assertj.core.api.Assertions.*;
public class MethodOverloadingUnitTest {
private static Multiplier multiplier;
@BeforeClass
public static void setUpMultiplierInstance() {
multiplier = new Multiplier();
}
@Test
public void givenMultiplierInstance_whenCalledMultiplyWithTwoIntegers_thenOneAssertion() {
assertThat(multiplier.multiply(10, 10)).isEqualTo(100);
}
@Test
public void givenMultiplierInstance_whenCalledMultiplyWithTreeIntegers_thenOneAssertion() {
assertThat(multiplier.multiply(10, 10, 10)).isEqualTo(1000);
}
@Test
public void givenMultiplierInstance_whenCalledMultiplyWithIntDouble_thenOneAssertion() {
assertThat(multiplier.multiply(10, 10.5)).isEqualTo(105.0);
}
@Test
public void givenMultiplierInstance_whenCalledMultiplyWithDoubleDouble_thenOneAssertion() {
assertThat(multiplier.multiply(10.5, 10.5)).isEqualTo(110.25);
}
@Test
public void givenMultiplierInstance_whenCalledMultiplyWithIntIntAndMatching_thenNoTypePromotion() {
assertThat(multiplier.multiply(10, 10)).isEqualTo(100);
}
}

68
core-java-lang/src/test/java/com/baeldung/methodoverloadingoverriding/test/MethodOverridingUnitTest.java Normal file
View File

@@ -0,0 +1,68 @@
package com.baeldung.methodoverloadingoverriding.test;
import com.baeldung.methodoverloadingoverriding.model.Car;
import com.baeldung.methodoverloadingoverriding.model.Vehicle;
import org.junit.BeforeClass;
import org.junit.Test;
import static org.assertj.core.api.Assertions.*;
public class MethodOverridingUnitTest {
private static Vehicle vehicle;
private static Car car;
@BeforeClass
public static void setUpVehicleInstance() {
vehicle = new Vehicle();
}
@BeforeClass
public static void setUpCarInstance() {
car = new Car();
}
@Test
public void givenVehicleInstance_whenCalledAccelerate_thenOneAssertion() {
assertThat(vehicle.accelerate(100)).isEqualTo("The vehicle accelerates at : 100 MPH.");
}
@Test
public void givenVehicleInstance_whenCalledRun_thenOneAssertion() {
assertThat(vehicle.run()).isEqualTo("The vehicle is running.");
}
@Test
public void givenVehicleInstance_whenCalledStop_thenOneAssertion() {
assertThat(vehicle.stop()).isEqualTo("The vehicle has stopped.");
}
@Test
public void givenCarInstance_whenCalledAccelerate_thenOneAssertion() {
assertThat(car.accelerate(80)).isEqualTo("The car accelerates at : 80 MPH.");
}
@Test
public void givenCarInstance_whenCalledRun_thenOneAssertion() {
assertThat(car.run()).isEqualTo("The vehicle is running.");
}
@Test
public void givenCarInstance_whenCalledStop_thenOneAssertion() {
assertThat(car.stop()).isEqualTo("The vehicle has stopped.");
}
@Test
public void givenVehicleCarInstances_whenCalledAccelerateWithSameArgument_thenNotEqual() {
assertThat(vehicle.accelerate(100)).isNotEqualTo(car.accelerate(100));
}
@Test
public void givenVehicleCarInstances_whenCalledRun_thenEqual() {
assertThat(vehicle.run()).isEqualTo(car.run());
}
@Test
public void givenVehicleCarInstances_whenCalledStop_thenEqual() {
assertThat(vehicle.stop()).isEqualTo(car.stop());
}
}

32
core-java-lang/src/test/java/com/baeldung/polymorphism/PolymorphismUnitTest.java Normal file
View File

@@ -0,0 +1,32 @@
package com.baeldung.polymorphism;
import static org.junit.Assert.*;
import java.awt.image.BufferedImage;
import org.junit.Test;
public class PolymorphismUnitTest {
@Test
public void givenImageFile_whenFileCreated_shouldSucceed() {
ImageFile imageFile = FileManager.createImageFile("SampleImageFile", 200, 100, new BufferedImage(100, 200, BufferedImage.TYPE_INT_RGB).toString()
.getBytes(), "v1.0.0");
assertEquals(200, imageFile.getHeight());
}
// Downcasting then Upcasting
@Test
public void givenTextFile_whenTextFileCreatedAndAssignedToGenericFileAndCastBackToTextFileOnGetWordCount_shouldSucceed() {
GenericFile textFile = FileManager.createTextFile("SampleTextFile", "This is a sample text content", "v1.0.0");
TextFile textFile2 = (TextFile) textFile;
assertEquals(6, textFile2.getWordCount());
}
// Downcasting
@Test(expected = ClassCastException.class)
public void givenGenericFile_whenCastToTextFileAndInvokeGetWordCount_shouldFail() {
GenericFile genericFile = new GenericFile();
TextFile textFile = (TextFile) genericFile;
System.out.println(textFile.getWordCount());
}
}

61
core-java-lang/src/test/java/com/baeldung/recursion/RecursionExampleUnitTest.java Normal file
View File

@@ -0,0 +1,61 @@
package com.baeldung.recursion;
import org.junit.Assert;
import org.junit.Test;
public class RecursionExampleUnitTest {
RecursionExample recursion = new RecursionExample();
@Test
public void testPowerOf10() {
int p0 = recursion.powerOf10(0);
int p1 = recursion.powerOf10(1);
int p4 = recursion.powerOf10(4);
Assert.assertEquals(1, p0);
Assert.assertEquals(10, p1);
Assert.assertEquals(10000, p4);
}
@Test
public void testFibonacci() {
int n0 = recursion.fibonacci(0);
int n1 = recursion.fibonacci(1);
int n7 = recursion.fibonacci(7);
Assert.assertEquals(0, n0);
Assert.assertEquals(1, n1);
Assert.assertEquals(13, n7);
}
@Test
public void testToBinary() {
String b0 = recursion.toBinary(0);
String b1 = recursion.toBinary(1);
String b10 = recursion.toBinary(10);
Assert.assertEquals("0", b0);
Assert.assertEquals("1", b1);
Assert.assertEquals("1010", b10);
}
@Test
public void testCalculateTreeHeight() {
BinaryNode root = new BinaryNode(1);
root.setLeft(new BinaryNode(1));
root.setRight(new BinaryNode(1));
root.getLeft().setLeft(new BinaryNode(1));
root.getLeft().getLeft().setRight(new BinaryNode(1));
root.getLeft().getLeft().getRight().setLeft(new BinaryNode(1));
root.getRight().setLeft(new BinaryNode(1));
root.getRight().getLeft().setRight(new BinaryNode(1));
int height = recursion.calculateTreeHeight(root);
Assert.assertEquals(4, height);
}
}