You can generate your own mockdata at https://mockaroo.com/
Reading Mock Data file :
- Place your mock data in your resource folder
- Write the below piece of code to read your data
public class MockData {
public static ImmutableList<Person> getPeople() throws IOException {
InputStream inputStream = Resources.getResource("people.json").openStream();
String json = IOUtils.toString(inputStream);
Type listType = new TypeToken<ArrayList<Person>>() {
}.getType();
List<Person> people = new Gson().fromJson(json, listType);
return ImmutableList.copyOf(people);
}
public static ImmutableList<Car> getCars() throws IOException {
InputStream inputStream = Resources.getResource("cars.json").openStream();
String json = IOUtils.toString(inputStream);
Type listType = new TypeToken<ArrayList<Car>>() {
}.getType();
List<Car> cars = new Gson().fromJson(json, listType);
return ImmutableList.copyOf(cars);
}
build.gradle
plugins {
id 'java'
id 'application'
}
repositories {
jcenter()
}
dependencies {
implementation 'com.google.guava:guava:28.0-jre'
testImplementation 'junit:junit:4.12'
testImplementation 'com.google.guava:guava:11.0.2'
testImplementation 'org.assertj:assertj-core:3.6.1'
testImplementation 'com.google.code.gson:gson:2.3.1'
testImplementation 'commons-io:commons-io:2.6'
}
application {
mainClassName = 'java8.App'
}
Below are the json file downloaded from mockaroo (people.json and cars.json)
Beans :
package beans;
public class Car {
private final Integer id;
private final String make;
private final String model;
private final String color;
private final Integer year;
private final Double price;
public Car(Integer id, String make, String model, String color, Integer year,
Double price) {
this.id = id;
this.make = make;
this.model = model;
this.color = color;
this.year = year;
this.price = price;
}
public Integer getId() {
return id;
}
public String getMake() {
return make;
}
public String getModel() {
return model;
}
public String getColor() {
return color;
}
public Integer getYear() {
return year;
}
public Double getPrice() {
return price;
}
@Override
public String toString() {
return "Car{" +
"id=" + id +
", make='" + make + '\'' +
", model='" + model + '\'' +
", color='" + color + '\'' +
", year=" + year +
", price=" + price +
'}';
}
}
package beans;
public class Person {
final Integer id;
final String firstName;
final String lastName;
final String email;
final String gender;
final Integer age;
public Person(Integer id, String firstName, String lastName, String email, String gender,
Integer age) {
this.id = id;
this.firstName = firstName;
this.lastName = lastName;
this.email = email;
this.gender = gender;
this.age = age;
}
public Integer getId() {
return id;
}
public String getFirstName() {
return firstName;
}
public String getLastName() {
return lastName;
}
public String getEmail() {
return email;
}
public String getGender() {
return gender;
}
public Integer getAge() {
return age;
}
@Override
public String toString() {
return "Person{" +
"id=" + id +
", firstName='" + firstName + '\'' +
", lastName='" + lastName + '\'' +
", email='" + email + '\'' +
", gender='" + gender + '\'' +
", age=" + age +
'}';
}
}
package beans;
public class PersonDTO {
private final Integer id;
private final String name;
private final Integer age;
public PersonDTO(Integer id, String name, Integer age) {
this.id = id;
this.name = name;
this.age = age;
}
public Integer getId() {
return id;
}
public String getName() {
return name;
}
public Integer getAge() {
return age;
}
@Override
public String toString() {
return "PeopleDTO{" +
"id=" + id +
", name='" + name + '\'' +
", age=" + age +
'}';
}
public static PersonDTO map(Person person) {
return new PersonDTO(person.getId(), person.getFirstName(), person.getAge());
}
}
Example :
@Test
public void declarativeApproachUsingStreams() throws Exception {
ImmutableList<Person> people = MockData.getPeople();
MockData.getPeople()
.stream()
.filter(p -> p.getAge() <= 18)
.limit(10)
.collect(Collectors.toList())
.forEach(System.out::println);
}
