Web Services & REST Lab Manual

JAVA Web Services & REST FULL STACK DEVELOPMENT

Objectives of this Lab Manual This lab manual includes - Exercises for hands on practice Guidelines to complete the exercise Learning Outcome

Implementation of RESTful Web Service using Spring

Problem What will you do? Statement • Create a RESTful Web Service to display the Subject offered by an institution • First of all, create a Spring project • Next, create a Rest controller for mapping of URL • Then, map the URL for displaying a JSON of available subjects • Create the respective services and entities for the web service

Solution What will be the steps Steps to get the output? • Step 1: Open the spring initializer to create a spring project. Give an appropriate artifact and group name to the project. Add in the dependencies of Spring Web to your project. Now generate the project.

Solution What will be the steps Steps to get the output? • Step 1: Open the spring initializer to create a spring project. • Step 2: Give an appropriate artifact and group name to the project. • Step 3: Add in the dependencies of Spring Web to your project. • Step 4: Now generate the project.

Solution What will be the steps Steps to get the output? • Step2: Now unzip the downloaded project. Open Spring Tool Suite, select File menu and choose the option to import the project. Now, select existing maven project option and then browse to your downloaded project.

Solution What will be the steps Steps to get the output? • Step3: Now create the subject class. This class has int id and String name as properties. Define default and parameterized constructor for this class. Define getter and setter methods for the same. Finally, override the toString method. • Step 4: Create an interface service with the name as myService. The interface contains an abstract method to return a list of subjects.

Solution What will be the steps Steps to get the output? • Step 5: Next create the service that implements and defines the mentioned abstract method to return a list of subjects. Create objects of the Subject class and store them in the list. Now override the get subject method to return the list of subjects. Make sure to annotate the class with Service to inform Spring. • Step 6: Finally it is time to create the REST controller. Create a class named myController and annotate it as Rest Controller. Inject the service using autowired annotation. Map the subject URL by calling the get subject method. Mention the mapping through get mapping annotation. Make sure to import all the classes and packages necessary.

Solution What will be the steps Steps to get the output? • Step 7: Now it is time to run the application. Make sure to run it is Spring Boot App.

Solution What will be the steps Steps to get the output? • Step 8: Take a note of the port number of the tomcat server in the output.

Solution What will be the steps Steps to get the output? • Step 9: Open Postman and type localhost colon followed by the port number. Then mention the URL for displaying subjects. Hit send and observe the output.

Code Code for step 3: public class Subject { private int id; private String name; public Subject(int id, String name) { super(); this.id = id; this.name = name; } public Subject() { }

Code Code for step 3 (): public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; }

Code Code for step 3 (): public void setName(String name) { this.name = name; } @Override public String toString() { return \"Module [id=\" + id + \", name=\" + name + \"]\"; } }

Code Code for step 4 : import java.util.ArrayList; public interface myService { public ArrayList<Subject> getSubject(); }

Code Code for step 5: @Service public class SubjectService implements myService { ArrayList<Subject> l; public SubjectService() { l = new ArrayList<>(); Subject s1 = new Subject(101,\"Core Java\"); Subject s2 = new Subject(102,\"Spring Boot\"); Subject s3 = new Subject(103,\"Micro Service\"); Subject s4 = new Subject(104,\"React\"); Subject s5 = new Subject(105,\"Angular\");

Code Code for step 5() : l.add(s1); l.add(s2); l.add(s3); l.add(s4); l.add(s5); }@Override public ArrayList<Subject> getSubject() { return l; } }

Code Code for step 6 : import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class myController { @Autowired

Code Code for step 6() : private SubjectService subService; @GetMapping(\"/subjects\") public List<Subject> getSubject() { return this.subService.getSubject(); } }

Learning Outcome After Performing this Add teExxt ehrecries:e- You will be able to: • Work with Spring Application, RESTful Web Services

Happy Learning!