Implemented service, repository and controller for each entity

src/main/java/com/faf223/expensetrackerfaf/controller/ExpenseController.java

@@ -0,0 +1,31 @@
+package com.faf223.expensetrackerfaf.controller;
+
+import com.faf223.expensetrackerfaf.model.Expense;
+import com.faf223.expensetrackerfaf.service.ExpenseService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/expenses")
+public class ExpenseController {
+
+    @Autowired
+    private ExpenseService expenseService;
+
+    @GetMapping("/user/{userUuid}")
+    public ResponseEntity<List<Expense>> getExpensesByUser(@PathVariable String userUuid) {
+        List<Expense> expenses = expenseService.getExpensesByUserId(userUuid);
+        if (!expenses.isEmpty()) {
+            return ResponseEntity.ok(expenses);
+        } else {
+            return ResponseEntity.notFound().build();
+        }
+    }
+}
+