Http Get Method Spring Boot Tutorial

Table of Contents

HTTP GET method is commonly used to retrieve data from a server. It’s another operation of Spring CRUD Operation.

Http POST method used to store and read data from server example and implementation explained here

READ (R): Create RESTFul api to read data from server, We can use Http Get method to read the data from table. Here is basic step

Step 1: Create java file BookController.java and then put below code in controller, here we have created method call getBook() .

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import com.techbug.techbug.service.BookService;
import com.techbug.techbug.vo.BookVO;

@RestController
public class BookController {
@Autowired
private BookService bookService;

@GetMapping(value = "/readbook")
public Object readBook() {
  return bookService.readBook();
  }
}

Step 2: Create Service file called BookService.java and define readBook() method, inside readBook() method we have used bookRepository.findAll(), findAll() is predefined hibernate method which fetch all records from table. @Autowired BookService bookService which allows to access all method which is declared BookService class.

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.techbug.techbug.entity.Book;
import com.techbug.techbug.repository.BookRepository;
import com.techbug.techbug.vo.BookVO;

@Service
public class BookService {

@Autowired
private BookRepository bookRepository;

public Object readBook() {
    return bookRepository.findAll();
  }
}

Step 3: Create an Interface and extend JPARepository inside interface and map table entity where data has to be stored or populated, each repository represents individual table entity.

import org.springframework.data.jpa.repository.JpaRepository;
import com.techbug.techbug.entity.Book;
public interface BookRepository extends JpaRepository<Book, Long>{
}

Step 4: Now run as java application and hit you end point using api validation tool, such as POSTMAN or Browser since its get method.

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