如何將 HashMap 添加到員工列表 class

Question

我創建了一個 Java class 並使用 JPA 檢索員工 ZA2F2ED4F8EBC2CBB1DZC21 的詳細信息

[
  {
    "empId": "1",
    "empName": "emp1",
    "empTag": "empTag1",
    "empState": "ACTIVE"
  },
  {
    "empId": "2",
    "empName": "emp2",
    "empTag": "empTag2",
    "empState": "ACTIVE"
  }
]

在收到 hash 的列表后，我想添加一些虛擬條目，例如

[
  {
    "empId": "00",
    "empName": "DummyEmp",
    "empTag": "DummyEmpTag",
    "empState": "ACTIVE"
  },
  {
    "empId": "1",
    "empName": "emp1",
    "empTag": "empTag1",
    "empState": "ACTIVE"
  },
  {
    "empId": "2",
    "empName": "emp2",
    "empTag": "empTag2",
    "empState": "ACTIVE"
  }
]

所以我試圖將 map 添加到員工列表中，但在運行時我得到了

java.lang.ClassCastException: java.util.HashMap$KeySet cannot be cast to com.domain.EmployeeBean 

我的員工 Class：

@Table(name = "employee")
@Entity
public class EmployeeBean implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id @Column(name = "emp_id") 
    private String empId;
    
    @Column(name = "emp_name") 
    private String empName;
    
    @Column(name = "emp_tag") 
    private String empTag;
    
    @Column(name = "emp_state") 
    private String empState;

    .... (getters and setters) 
}

存儲庫：-

public interface EmployeeBeanRepository extends JpaRepository<EmployeeBean, String>{

    List < EmployeeBean > findByEmpState(String empState);

資源：-

@RestController
@RequestMapping("/empDetails")
public class EmployeeBeanResource {
    
private final EmployeeBeanRepository empBeanRepository;
    
    public EmployeeBeanResource(EmployeeBeanRepository empBeanRepository) {
        this.empBeanRepository = empBeanRepository;
    }
        
    @GetMapping("/empState/{empState}")
    @Timed
    public List<EmployeeBean> getEmployeesByStatus(@PathVariable String empState) {
        List<EmployeeBean> activeEmployeeList = empBeanRepository.findByEmpState(empState);
        
        Map<String, String> empDummy = new HashMap<>();
        
        empDummy.put("empId", "00");
        empDummy.put("empName", "DummyEmp");
        empDummy.put("empTag", "DummyEmpTag");
        empDummy.put("empState", "ACTIVE");
        
        activeEmployeeList.add((EmployeeBean) empDummy.keySet());
        activeEmployeeList.add((EmployeeBean) empDummy.values());
       
        return activeEmployeeList;
    }
}

我已經嘗試了很多，但仍然無法找到將 map 添加到員工列表中的方法。

Answer 1

而不是這個：

Map<String, String> empDummy = new HashMap<>();
        
empDummy.put("empId", "00");
empDummy.put("empName", "DummyEmp");
empDummy.put("empTag", "DummyEmpTag");
empDummy.put("empState", "ACTIVE");
        
activeEmployeeList.add((EmployeeBean) empDummy.keySet());

嘗試以下操作：

EmployeeBean empDummy = new EmployeeBean();
        
empDummy.setEmpId("00");
empDummy.setEmpName("DummyEmp");
empDummy.setEmpTag("DummyEmpTag");
empDummy.setEmpState("ACTIVE");
        
activeEmployeeList.add(empDummy);

或者如果你有所有 args 構造函數：

EmployeeBean empDummy = new EmployeeBean("00", "DummyEmp","DummyEmpTag","ACTIVE");

activeEmployeeList.add(empDummy);