Webアプリ作成　Spring Boot
⑤検索条件からデータ取得　一覧画面表示

package diary.form.diary;

public class GetForm {

	private String category;
	private String date;
	public String getCategory() {
		return category;
	}
	public void setCategory(String category) {
		this.category = category;
	}
	public String getDate() {
		return date;
	}
	public void setDate(String date) {
		this.date = date;
	}

}

package diary.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;

import diary.entity.Diary;
import diary.form.GetForm;
import diary.service.DiaryService;

@Controller
@RequestMapping("/diary")
public class DiaryController {
	
	private final DiaryService diaryservice;
	
	@Autowired
	public DiaryController(DiaryService diaryservice) {
		this.diaryservice = diaryservice;
	}

	/**
     * 日記アプリの一覧画面を表示
     * @param model
     * @return resources/templates/list.html
     */
    @GetMapping
    public String diaryList(
    	@ModelAttribute GetForm form,
    	Model model
    ) {
    	List<Diary> list = diaryservice.findList(form);
    	model.addAttribute("list", list);
        model.addAttribute("getForm", form);
        return "list";
    }
}

  public List<Diary> findList(GetForm form) {
        return dao.findList(form);
 }

List<Diary> findList(GetForm form);

    @Override
	public List<Diary> findList(GetForm form) {
		StringBuilder sqlBuilder = new StringBuilder();
		sqlBuilder.append("SELECT d.id, d.category, d.title, d.content, TO_CHAR(d.date, 'YYYY/MM/DD') AS date, d.update_datetime, c.name "
				+ "FROM diary AS d INNER JOIN code AS c ON d.category = c.cd "
				+ "WHERE c.group_cd = '01'");

		// パラメータ設定用Map
		Map<String, String> param = new HashMap<>();
		// パラメータが存在した場合、where句にセット
		if(form.getCategory() != null && form.getCategory() != "") {
			sqlBuilder.append(" AND c.cd = :cd");
			param.put("cd", form.getCategory());
		}
		if(form.getDate() != null && form.getDate() != "") {
			sqlBuilder.append(" AND TO_CHAR(d.date, 'YYYY/MM') = :date");
			param.put("date", form.getDate());
		}

		String sql = sqlBuilder.toString();

		//タスク一覧をMapのListで取得
		List<Map<String, Object>> resultList = jdbcTemplate.queryForList(sql, param);
		//return用の空のListを用意
		List<Diary> list = new ArrayList<Diary>();

		//データをDiaryにまとめる
		for(Map<String, Object> result : resultList) {
			Diary diary = new Diary();
			diary.setId((int)result.get("id"));
			diary.setCategory((String)result.get("category"));
			diary.setTitle((String)result.get("title"));
			diary.setContent((String)result.get("content"));
			diary.setDate((String)result.get("date"));
			diary.setUpdate_datetime((Timestamp)result.get("update_datetime"));
			diary.setName((String)result.get("name"));
			list.add(diary);
		}
		return list;
	}

    <div class="container-fluid">
      <div class="search m-2">
        <form method="GET" th:action="@{/diary}" th:object="${getForm}">
          <div class="row">
            <div class="form-group col-3 m-2">
              <label for="category">分類</label>
              <select id="category" name="category" class="form-select col-2" th:value="${getForm.category}">
                <option></option>
                <option value="1" th:selected="${getForm.category} == 1">仕事</option>
                <option value="2" th:selected="${getForm.category} == 2">趣味</option>
                <option value="3" th:selected="${getForm.category} == 3">その他</option>
              </select>
            </div>
            <div class="form-group col-3 m-2">
              <label for="category">年月</label>
              <input type="text" class="form-control" id="date_sample" name="date" th:value="${getForm.date}">
            </div>
          </div>
          <div class="row">
            <div class="col-1 m-1">
              <button type="submit" class="btn btn-primary">検索</button>
            </div>
          </div>
        </form>
      </div>

      <div class="list">
        <table id="table" class="table table-striped table-hover">
          <thead class="thead-lignt">
              <tr>
                <th class="col-2">日付</th>
                <th class="col-2">分類</th>
                <th class="col-6">題名</th>
                <th class="col-1"></th>
                <th class="col-1"></th>
              </tr>
          </thead>
          <tbody>
            <tr th:each="item: ${list}">
              <td th:text=${item.date}></td>
              <td th:text=${item.name}></td>
              <td th:text=${item.title}></td>
              <td>
                <a class="btn btn-primary">詳細</a>
              </td>
              <td>
                <button type="button" class="btn btn-danger">削除</button>
              </td>
            </tr>
          </tbody>
        </table>
      </div>