[EDIT] 変更したテーブルに合わせてメソッドを修正しました。

src/main/java/com/example/demo/app/domain/model/GoalModel.java

@@ -3,6 +3,7 @@ package com.example.demo.app.domain.model;
 import java.time.LocalDate;
 
 import com.example.demo.app.infra.entity.GoalEntity;
+import com.example.demo.app.infra.entity.UserEntity;
 import com.example.demo.app.presentation.form.GoalForm;
 
 import lombok.AllArgsConstructor;
@@ -27,8 +28,10 @@ public class GoalModel {
 	private Integer achievementRate; // 達成率
 	
 	private Integer currentAmount; // 現在の資産
+	
+	private Long userId;
 
-	public static GoalModel convertFrom(GoalEntity goalEntity) {
+	public static GoalModel convertFrom(GoalEntity goalEntity, int achievementRate, int currentAmount) {
 		return new GoalModel(
 				goalEntity.getGoalId(),
 				goalEntity.getGoalTitle(),
@@ -36,10 +39,12 @@ public class GoalModel {
 				goalEntity.getTargetAmount(),
 				goalEntity.getDeadline(),
 				goalEntity.getGoalComplete(),
-				null,null);
+				achievementRate,
+				currentAmount,
+				goalEntity.getUserEntity().getUserId());
 	}
 
-	public static GoalEntity convertTo(GoalModel goalModel) {
+	public static GoalEntity convertTo(GoalModel goalModel, UserEntity userEntity) {
 		return new GoalEntity(
 				goalModel.getGoalId(),
 				goalModel.getGoalTitle(),
@@ -47,7 +52,7 @@ public class GoalModel {
 				goalModel.getTargetAmount(),
 				goalModel.getDeadline(),
 				goalModel.getGoalComplete(),
-				null);
+				userEntity, 0);
 	}
 	
 	public static GoalModel convertFrom(GoalForm goalForm) {
@@ -58,7 +63,8 @@ public class GoalModel {
 				goalForm.getTargetAmount(),
 				goalForm.getDeadline(),
 				goalForm.getGoalComplete()
-				,null,null);
+				,null,null,
+				goalForm.getUserId());
 	}
 
 }

src/main/java/com/example/demo/app/domain/service/GoalService.java

@@ -1,16 +1,18 @@
 package com.example.demo.app.domain.service;
 
+import java.util.List;
+
 import com.example.demo.app.domain.model.GoalModel;
 
 public interface GoalService {
 
 	GoalModel getGoalById(Long goalId);
 	
-	GoalModel getGoalByUserId(Long userId); 
+	public List<GoalModel> getGoalByUserId(Long userId); 
 
-	GoalModel createGoal(GoalModel goalModel);
+	public GoalModel createGoal(GoalModel goalModel, Long userId);
 
-	GoalModel updateGoal(GoalModel goalModel);
+	GoalModel updateGoal(GoalModel goalModel, Long userId);
 
 //	void deleteGoal(Long goalId);
 

src/main/java/com/example/demo/app/domain/service/impl/GoalServiceImpl.java

@@ -1,5 +1,8 @@
 package com.example.demo.app.domain.service.impl;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import org.springframework.stereotype.Service;
 
 import com.example.demo.app.domain.model.GoalModel;
@@ -21,14 +24,14 @@ public class GoalServiceImpl implements GoalService {
 	@Override
 	public GoalModel getGoalById(Long goalId) {
 		GoalEntity goalEntity = goalRepository.findById(goalId).orElse(null);
-		return GoalModel.convertFrom(goalEntity);
+		return GoalModel.convertFrom(goalEntity, 0, 0);
 	}
 
 	@Override
-	public GoalModel getGoalByUserId(Long userId) {
+	public List<GoalModel> getGoalByUserId(Long userId) {
 
 		UserEntity userEntity = userRepository.findById(userId).orElseThrow();
-		GoalEntity goalEntity = userEntity.getGoalEntity();
+		List<GoalEntity> goalEntityList = goalRepository.findAllByUserId(userId);
 
 		// 収支の合計を計算(収入はプラス、支出はマイナス)
 		int transactionTotal = userEntity.getTransactionEntityList().stream()
@@ -42,42 +45,38 @@ public class GoalServiceImpl implements GoalService {
 		int currentAmount = userEntity.getSaving() + transactionTotal;
 
 		// 達成率(%) = 現在の資産 ÷ 目標金額 × 100
-		int achievementRate = 
-				(goalEntity.getTargetAmount() == null)
-				? 0	: 
-				(int) ((currentAmount * 100.0) / goalEntity.getTargetAmount());
 
-		GoalModel goalModel = GoalModel.convertFrom(goalEntity);
+		List<GoalModel> goalModelList = new ArrayList<GoalModel>();
 
-		return new GoalModel(
+		goalEntityList.stream()
-				goalModel.getGoalId(),
+				.forEach(goalEntity -> goalModelList.add(GoalModel.convertFrom(goalEntity,
-				goalModel.getGoalTitle(),
+						(goalEntity.getTargetAmount() == null)
-				goalModel.getGoalSubtitle(),
+								? 0
-				goalModel.getTargetAmount(),
+								: (int) ((currentAmount * 100.0) / goalEntity.getTargetAmount()),
-				goalModel.getDeadline(),
+						currentAmount)));
-				goalModel.getGoalComplete(),
+
-				achievementRate,
+
-				currentAmount);   
+		return goalModelList;
 	}
-	
-	@Override
-	public GoalModel createGoal(GoalModel goalModel) {
 
-		GoalEntity goalEntity = GoalModel.convertTo(goalModel);
+	@Override
+	public GoalModel createGoal(GoalModel goalModel, Long userId) {
+
+		GoalEntity goalEntity = GoalModel.convertTo(goalModel, userRepository.findById(userId).get());
 
 		GoalEntity savedGoalEntity = goalRepository.save(goalEntity);
 
-		return GoalModel.convertFrom(savedGoalEntity);
+		return GoalModel.convertFrom(savedGoalEntity, 0, 0);
 	}
 
 	@Override
-	public GoalModel updateGoal(GoalModel goalModel) {
+	public GoalModel updateGoal(GoalModel goalModel, Long userId) {
 
-		GoalEntity goalEntity = GoalModel.convertTo(goalModel);
+		GoalEntity goalEntity = GoalModel.convertTo(goalModel, userRepository.findById(userId).get());
 
 		GoalEntity updatedGoalEntity = goalRepository.save(goalEntity);
 
-		return GoalModel.convertFrom(updatedGoalEntity);
+		return GoalModel.convertFrom(updatedGoalEntity, 0, 0);
 	}
 
 }

src/main/java/com/example/demo/app/infra/entity/GoalEntity.java

@@ -4,10 +4,12 @@ import java.time.LocalDate;
 
 import jakarta.persistence.Column;
 import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.GenerationType;
 import jakarta.persistence.Id;
-import jakarta.persistence.OneToOne;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
 import jakarta.persistence.Table;
 
 import lombok.AllArgsConstructor;
@@ -41,7 +43,10 @@ public class GoalEntity {
 	@Column(name = "goal_complete", nullable = false)
 	private Integer goalComplete = 0;
 	
-	@OneToOne(mappedBy = "goalEntity")
+	@ManyToOne(fetch = FetchType.LAZY)
+	@JoinColumn(name = "user_id")
 	private UserEntity userEntity;
+	
+	private Integer deleteFlag;
 
 }

src/main/java/com/example/demo/app/infra/entity/UserEntity.java

@@ -12,7 +12,6 @@ import jakarta.persistence.Id;
 import jakarta.persistence.JoinColumn;
 import jakarta.persistence.ManyToOne;
 import jakarta.persistence.OneToMany;
-import jakarta.persistence.OneToOne;
 import jakarta.persistence.Table;
 
 import lombok.AllArgsConstructor;
@@ -65,9 +64,8 @@ public class UserEntity {
 	@JoinColumn(name = "secret_question_id")
 	private QuestionEntity questionEntity;
 	
-	@OneToOne(fetch = FetchType.LAZY)
+	@OneToMany(mappedBy = "userEntity")
-	@JoinColumn(name = "goal_id")
+	private List<GoalEntity> goalEntityList;
-	private GoalEntity goalEntity;
 	
 	@ManyToOne(fetch = FetchType.LAZY)
 	@JoinColumn(name = "course_id")

src/main/java/com/example/demo/app/infra/repository/GoalRepository.java

@@ -1,6 +1,9 @@
 package com.example.demo.app.infra.repository;
 
+import java.util.List;
+
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
 import org.springframework.stereotype.Repository;
 
 import com.example.demo.app.infra.entity.GoalEntity;
@@ -8,4 +11,7 @@ import com.example.demo.app.infra.entity.GoalEntity;
 @Repository
 public interface GoalRepository extends JpaRepository<GoalEntity, Long> {
 	
+	@Query("select g from GoalEntity g where g.userEntity.userId = :userId")
+	public List<GoalEntity> findAllByUserId(Long userId);
+	
 }

src/main/java/com/example/demo/app/presentation/controller/GoalController.java

@@ -69,7 +69,7 @@ public class GoalController {
 		}
 
 		GoalModel goalModel = GoalModel.convertFrom(goalForm);
-		goalService.updateGoal(goalModel);
+		goalService.updateGoal(goalModel, userId);
 
 		return "redirect:/goal";
 	}

src/main/java/com/example/demo/app/presentation/controller/TransactionController.java

@@ -27,7 +27,6 @@ import com.example.demo.app.domain.service.UserService;
 import com.example.demo.app.presentation.form.CategoryForm;
 import com.example.demo.app.presentation.form.Expense;
 import com.example.demo.app.presentation.form.FixedCostForm;
-import com.example.demo.app.presentation.form.GoalForm;
 import com.example.demo.app.presentation.form.Income;
 import com.example.demo.app.presentation.form.TransactionForm;
 import com.example.demo.app.presentation.form.UserForm;
@@ -349,19 +348,19 @@ public class TransactionController {
 		model.addAttribute("totalIncome", totalIncome);
 		model.addAttribute("totalExpense", totalExpense);
 
-		GoalForm goalForm = GoalForm.convertFrom(goalService.getGoalByUserId(loginUser.getUserId()));
+//		List<GoalForm> goalForm = GoalForm.convertFrom(goalService.getGoalByUserId(loginUser.getUserId()));
 
 		UserForm userForm = UserForm.convertFrom(userService.findByUserId(loginUser.getUserId()));
 
-		model.addAttribute("achievementRate", goalForm.getAchievementRate());
+//		model.addAttribute("achievementRate", goalForm.getAchievementRate());
-		
+//		
-	    model.addAttribute("currentAmount", goalForm.getCurrentAmount());
+//	    model.addAttribute("currentAmount", goalForm.getCurrentAmount());
-
+//
-		model.addAttribute("targetAmount", goalForm.getTargetAmount());
+//		model.addAttribute("targetAmount", goalForm.getTargetAmount());
 
 		model.addAttribute("saving", userForm.getSaving());
 
-		model.addAttribute("deadline", goalForm.getDeadline());
+//		model.addAttribute("deadline", goalForm.getDeadline());
 
 		return "menu";
 	}

src/main/java/com/example/demo/app/presentation/form/GoalForm.java

@@ -1,6 +1,7 @@
 package com.example.demo.app.presentation.form;
 
 import java.time.LocalDate;
+import java.util.List;
 
 import org.springframework.format.annotation.DateTimeFormat;
 
@@ -31,6 +32,8 @@ public class GoalForm {
 	private Integer achievementRate; // 達成率
 	
 	private Integer currentAmount; // 現在の資産
+	
+	private Long userId;
 
 	public static GoalForm convertFrom(GoalModel goalModel) {
 		return new GoalForm(
@@ -41,11 +44,12 @@ public class GoalForm {
 				goalModel.getDeadline(),
 				goalModel.getGoalComplete(),
 				goalModel.getAchievementRate(),
-				goalModel.getCurrentAmount());
+				goalModel.getCurrentAmount(),
+				goalModel.getUserId());
 	}
 
-//	public static List<GoalForm> convertFrom(List<GoalModel> goalModelList) {
+	public static List<GoalForm> convertFrom(List<GoalModel> goalModelList) {
-//		return goalModelList.stream().map(GoalForm::convertFrom).toList();
+		return goalModelList.stream().map(GoalForm::convertFrom).toList();
-//	}
+	}
 
 }

src/main/resources/templates/menu.html

@@ -113,17 +113,17 @@
 
 	</div>
 
-	<div>
+<!--	<div>-->
-		<span>目標貯金</span>
+<!--		<span>目標貯金</span>-->
-		<span th:text="${targetAmount}"></span>
+<!--		<span th:text="${targetAmount}"></span>-->
-		<span>円</span>
+<!--		<span>円</span>-->
-	</div>
+<!--	</div>-->
 	
-	<div>
+<!--	<div>-->
-			<span>現在高</span>
+<!--			<span>現在高</span>-->
-			<span th:text="${currentAmount}"></span>
+<!--			<span th:text="${currentAmount}"></span>-->
-			<span>円</span>
+<!--			<span>円</span>-->
-		</div>
+<!--		</div>-->
 
 	<div>
 		<span>貯金額</span>
@@ -133,16 +133,16 @@
 	
 	<hr>
 	
-	<div>
+<!--	<div>-->
-		<span>達成率</span>
+<!--		<span>達成率</span>-->
-		<span th:text="${achievementRate}"></span>
+<!--		<span th:text="${achievementRate}"></span>-->
-		<span>%</span>
+<!--		<span>%</span>-->
-	</div>
+<!--	</div>-->
-	<div>
+<!--	<div>-->
-		<span>達成期限</span>
+<!--		<span>達成期限</span>-->
-		<span th:text="${deadline}"></span>
+<!--		<span th:text="${deadline}"></span>-->
-		<span>円</span>
+<!--		<span>円</span>-->
-	</div>
+<!--	</div>-->
 
 	<div th:replace="~{footer :: footer}"></div>