Technology excerpt that can be used for creating EC sites in Java training

• Some sources such as getters and setters are omitted.

Settings used this time

build.gradle

dependencies {
	compile('org.springframework.boot:spring-boot-starter-data-jpa')
	compile('org.springframework.boot:spring-boot-starter-thymeleaf')
	compile('org.springframework.boot:spring-boot-starter-web')
	providedRuntime('org.springframework.boot:spring-boot-starter-tomcat')
	compile('mysql:mysql-connector-java')
}

Login information retention

It is convenient to pack in a session to carry around login information

@SessionScope
@Component
public class AccountModel {
	private String id;
	private String name;
}

@Controller
public class MainController {

	@Autowired
	private AccountModel accountModel;
	
	/**
 * Login process
	 * @param model
	 * @param id
	 * @param post
	 * @return
	 */
	@RequestMapping("login")
	public String login(Model model,@RequestParam("id") String id,@RequestParam("pass") String pass) {
		accountModel.setId(id);
 // TODO password check
		return "shop";
	}
}

  <form method="post" th:action="@{login}">
  	<input type="text" name="id" />
  	<input type="text" name="pass" />
 <button> Login </ button>
  </form>

With this, you can check it every time you log in for the first time. If you do not check and retain the session information at the time of purchase, you can move to the personal information registration screen.

Data search

See below for the naming rules for methods that are automatically implemented in SpringDataJPA. [Spring Data JPA] Naming rules for automatically implemented methods

@Entity
@Table(name="item")
public class Item {
	@Id
	@GeneratedValue
	private int id;
	private String name;
	private int price;
}

public interface ItemRepos extends JpaRepository<Item, Integer> {
	/**
	 * select * from item where name like %{name}%
	 * @param name
	 * @return
	 */
	public List<Item> findByNameContains(String name);
}

@Controller
public class MainController {

	@Autowired
	private ItemRepos itemRepos;

	/**
 * Search process
	 * @param model
	 * @param name
	 * @return
	 */
	@RequestMapping("search")
	public String search(Model model,@RequestParam("name") String name) {
		List<Item> itemList = itemRepos.findByNameContains(name);
		model.addAttribute("itemList", itemList);
		return "shop";
	}

}

  <form method="post" th:action="@{search}">
  		<input type="text" name="name"/>
 <button> Search </ button>
  </form>

Data registration

JpaRepository # save performs update if pk is duplicated, insert if not

	/**
 * registration process
	 * @param model
	 * @param name
	 * @param price
	 * @return
	 */
	@RequestMapping("submit")
	public String submit(Model model,@RequestParam("name") String name,@RequestParam("price") String price) {
		Item item = new Item();
		item.setName(name);
		item.setPrice(Integer.valueOf(price));
		itemRepos.save(item);
		return "shop";
	}

Caution

Since we are assuming training this time, we have not implemented detailed parts, but there are many points to consider such as input value check and separation of processing layer.