[Spring Boot2.4.2] フォームとエンティティの連携 – ソフトウェアエンジニアの技術ブログ：Software engineer tech blog

エンティティとは?
-> relational databaseの表を表す

src/main/resources/templates/test1/index.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="utf-8">
<title>check</title>
</head>
<body >
<form method="post" action="#" th:action="@{/test1/testform}" th:object="${test1Form}">
<p><input type="text" id="id" name="id" th:field="*{id}"/></p>
<p><input type="text" id="name" name="name" th:field="*{name}"></p>
<p><input type="submit" value="送信ボタン"></p>
</form>
</body>
</html>

フォームクラス: Test1Form.java
L controllerのmodel.addAttribute(“test1Form”, new Test1Form());でvalidationをかけている

package com.example.demo;

public class Test1Form {
	private Integer id;
	private String name;
	
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
}

エンティティのクラス: Syain.java (社員)
L formのvalidationと同じく、privateで宣言して、geter, setterを書く
L getter, setterは、データを外部から取得するメソッド、あるいはそのデータを外部から変更するメソッド

package com.example.demo;

public class Syain {
	private Integer id;
	private String name;
	
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
}

MainController.java

package com.example.demo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@Controller
@RequestMapping("/test1")
public class MainController {
	@Autowired
	private SyainRepository syainRepository;
	
    @GetMapping
    public String disp1(
    		Model model) {
    	model.addAttribute("test1Form", new Test1Form());
        return "test1/index";
    }
    @PostMapping("/testform")
	public String disp2(Test1Form test1Form) {
		    Syain syain = new Syain();
		    syain.setId(test1Form.getId());
		    syain.setName(test1Form.getName());
		    syainRepository.insertSyain(syain);
			return "redirect:/test1/";
		}
}

pom.xml

<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-jdbc</artifactId>
		</dependency>

SyainRepository.java

package com.example.demo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

@Repository
public class SyainRepository {
	private final JdbcTemplate jdbcTemplate;
	
	@Autowired
	public SyainRepository(JdbcTemplate jdbcTemplate) {
		this.jdbcTemplate = jdbcTemplate;
	}
	
	public void insertSyain(Syain syain) {
		jdbcTemplate.update("INSERT INTO syain(id,name) VALUES (?, ?)",
				syain.getId(), syain.getName());
	}
}

Description:

Failed to configure a DataSource: ‘url’ attribute is not specified and no embedded datasource could be configured.

Reason: Failed to determine a suitable driver class

なるほど、何となくわかってきた。