为所有响应定义通用基础 Java 模型的最佳方法是什么？

Question

我需要将所有 REST 响应格式化为：

{
    "response": {}
    "status": "ERROR"
    "error": {
        "status": "ERROR",
        "errors": [
            {
                "type": "ERROR",
                "code": "E1001",
                "message": "This is error 1.",
                "reference": "TEST 1"
            },
            {
                "type": "ERROR",
                "code": "E1002",
                "message": "This is error 2.",
                "reference": "TEST 2"
            }
        ]
    }
}

其中 response 是任意数据（对象、数组；具有任意字段）不同每个 REST API 端点。

为每个响应模型定义不同响应的最佳方法是什么？

我试过了（而且它有效，但我不确定这样做是否正确）：

BaseResponseModel.java

public class BaseResponseModel {
    
    private String status = "SUCCESS";
    private List<ErrorExtendedModel> errors = new ArrayList<>();
    
    // Various constructors, getters and setters
    
}

和子class:

CustomerResponseModel.java

public class CustomerResponseModel extends BaseResponseModel {

    public List<Response> response = new ArrayList<>();

    public static class Response { 
    
        private String customerId;
        private String firstName;
        private String lastName;
    
        public Response(String customerId, String firstName, String lastName) {
        
            this.customerId = customerId;
            this.firstName = firstName;
            this.lastName = lastName;
        }
    
        // getters and setters of inner class
    }

    public CustomerResponseModel() {
        super();
    }

    public List<Response> getResponse() {
        return response;
    }

    public void setResponse(List<Response> response) {
        this.response = response;
    }
}

我使用 inner static class 每个子class 中的字段，但我不确定这是正确的方法。

Answer 1

在这种情况下，我不会选择继承，而是选择组合并利用泛型。这种方法的优点是您不需要嵌套类，您在整个应用程序中强制执行基本 REST 模型，同时保持响应类型通用。

BaseResponseModel.java:

public class BaseResponseModel<T> {
    
    private T response;
    private String status = "SUCCESS";
    private List<ErrorExtendedModel> errors = new ArrayList<>();
    

    public BaseResponseModel(T response) {
        this.response = response;
    }

    // ...
    
}

CustomerResponseModel.java:

public class CustomerResponseModel {
            
    private String customerId;
    private String firstName;
    private String lastName;
    
    public CustomerResponseModel(String customerId, String firstName, String lastName) {      
        this.customerId = customerId;
        this.firstName = firstName;
        this.lastName = lastName;
    }

    // ...
}

用法示例：

public class RestApiController {
            
    public BaseResponseModel<CustomerResponseModel> getOneCustomer(String customerId) {      
        return new BaseResponseModel(new CustomerResponseModel(...));
    }

    public BaseResponseModel<List<CustomerResponseModel>> getAllCustomers() {      
        return new BaseResponseModel(List.of(new CustomerResponseModel(...), new CustomerResponseModel(...)));
    }

    // ...
}

为所有响应定义通用基础 Java 模型的最佳方法是什么？

What is the best way to define a common Base Java Model for all Responses?

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