接著繼續寫刪除特定員工的API EmployeeController.java // delete employees by id - version 1 @DeleteMapping("/employees/{id}") public ResponseEntity<Map<String, Boolean>> deleteEmployee(@PathVariable Long id) { Employee employee = employeeRepository.findById(id) .orElseThrow(() -> new ResourceNotFoundException("Employee ID not found:" + id)); employeeRepository.delete(employee); Map<String, Boolean> response = new HashMap<>(); response.put("delete", Boolean.TRUE); return ResponseEntity.ok(response); }

接著繼續寫更新特定員工的API EmployeeController.java // update employee by id - version 1 @PutMapping("/employees/{id}") public Employee updateEmployee(@PathVariable Long id, @RequestBody Employee newEmployee) { Employee employee = employeeRepository.findById(id) .orElseThrow(() -> new ResourceNotFoundException("Employee ID not found:" + id)); employee.setFirstName(newEmployee.getFirstName()); employee.setLastName(newEmployee.getLastName()); employee.setemailId(newEmployee.getemailId());

接著繼續寫查詢特定員工的API EmployeeController.java // read employee by id - Version 1 @GetMapping("/employees/{id}") public Employee getEmployeeById(@PathVariable Long id) { return employeeRepository.findById(id) .orElseThrow(() -> new ResourceNotFoundException("Employee ID not found:" + id)); } // read employee by id - version 2 @GetMapping("/employees/{id}") public ResponseEntity<Employee> getEmployeeById(@PathVariable Long id) { Employee employee = employeeRepository.findById(id) .orElseThrow(() -> new ResourceNotFoundException("Employee ID not found:" + id)); return ResponseEntity.ok(employee); }

前面已經完成跟驗證過第一隻 API 了 接著繼續寫，新增員工的 API EmployeeController.java // creat employee @PostMapping("/employees") public Employee createEmployee(@RequestBody Employee employee) { return employeeRepository.save(employee); } 寫完了，還滿簡單的吧 測試方法： 打開 Postman，記得改成 POST http://localhost:8080/api/v1/employees 在 Headers 裡新增一組 KYE：Content-Type VALUE：application/json 接者在 BODY 裡，填上要新增員工的內容，例如： { "firstName": "Chris", "lastName": "Evans", "emailId": "Chris_Evans@gmail.com" }

今天要來建立前端 前置步驟有二 NodeJs 官網下載 nodejs（安裝過程中，那個額外的工具應該不用打勾，幫我下載一堆東西，煩死） 老師的Github 下載 react-frondend 資料夾 照著老師的位置放進 react-frondend 後 我用 Intellij 內建的 Terminal（在下方）下指令 cd ..（退回上一層，因為我打開的時候是在 springboot-backend 的資料夾裡） cd react-frondend（進到這資料夾） npm start（啟動程序，我遇到的兩個 bug，解法在下方） npm WARN config global --global, --local are deprecated. Use --location=global instead ‘react-scripts’ 不是內部或外部命令，也不是可執行的程式 或批處理檔案 接著瀏覽器跳出畫面就成功啦，會看到老師弄好的畫面

在 src/main/java/controller 建立 EmployeeController.java package controller; import model.Employee; import org.springframework.beans.factory.annotation.Autowired; import org.springf …

在 src/main/java/exception 新增檔案 ResourceNotFoundException.java package exception; import org.springframework.http.HttpStatus; import org.springframework.web.bind.annotation.ResponseStatus; @ResponseStatus(value = HttpStatus.NOT_FOUND) public class ResourceNotFoundException extends RuntimeException { public static final long serialVersionUID = 1L; public ResourceNotFoundException(String message) { super(message); } }

在 src/main/java/repository 建立 EmployeeRepository.java package repository; import model.Employee; import org.springframework.data.jpa.repository.JpaRepository; import org.springframework.stereotype.Repository; @Repository public interface EmployeeRepository extends JpaRepository<Employee, Long> { } extends JpaRepository 就可以直接使用裡面很多寫好的 Method 像是 findAll()、saveAll()、getById() 後面寫實際業務邏輯的時候會非常方便 參考項目來源

在 src\main\java 新增四個資料夾 分別是 controller、exception、model、repository 在 model 裡新增 Employee.java package com.example.springbootbackend.model; import javax.persistence.*; @Entity @Table(name = "employees") public class Employee { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; private String firstName; private String lastName; private String emailId; public Employee() { }