用于表示 JSON 对象的通用 pojo

Question

简单地说，我正在尝试编写一个代表 JSON 对象的 POJO，类似于：

{
    "errorCode": "SYS101",
    "errorMessage": {
        "key1": "value1",
        "key2": "value2",
        "key3": "value3"
    }   
}

因为每个键的名字is random unique and not in any pattern和计数可能太多了，像下面这样写是没有用的：

public class Response {
    private String errorCode;
    private ErrorMessage errorMessage;

    public String getErrorCode() {
        return errorCode;
    }

    public void setErrorCode(String errorCode) {
        this.errorCode = errorCode;
    }

    public ErrorMessage getErrorMessage() {
        return errorMessage;
    }

    public void setErrorMessage(ErrorMessage errorMessage) {
        this.errorMessage = errorMessage;
    }
}

public class ErrorMessage {

    private String key1;
    private String key2;
    private String key3;

    public String getKey1() {
        return key1;
    }

    public void setKey1(String key1) {
        this.key1 = key1;
    }

    public String getKey2() {
        return key2;
    }

    public void setKey2(String key2) {
        this.key2 = key2;
    }

    public String getKey3() {
        return key3;
    }

    public void setKey3(String key3) {
        this.key3 = key3;
    }
}

我想知道是否有通用的方法来编写表示 JSON 的 POJO？

更新：键是随机字符串，它们不是任何数字模式：

比如你可以这样考虑：

{
    "errorCode": "SYS101",
    "errorMessage": {
        "firstName": "first name could not be empty",
        "age": "age could not be less thatn 18",
        "gender": "could not be null"

    }   
}

Answer 1

也许是这样的？它不是很“通用”，但您可以根据需要添加任意数量的错误消息，并且它仍然保留原始 JSON 的结构，其中 errorMessage 是一个对象（而不是数组）

public class Response {
    private String errorCode;
    private Map<String, String> errorMessage;   // JSONs are like maps with a key-value mapping

    public Response(String errorCode, String... errorMessages){   // example for a constructor with the logic to assign the errorMessages (no setters)
        this.errorCode = errorCode; 
        this.errorMessage= new HashMap<>();   // first you initialize the map
        int count =0;                         // a counter to name your "keyX" keys
        for(String msg:errorMessages){ 
           errorMessage.put("key"+(++count),msg); // and filling the map
        }          
    }
}

评论后更新

public class Response {
    private String errorCode;
    private Map<String, String> errorMessage;   // you can still keep this map
   
    public Response(String errorCode){        // I suppose the error messages can be added separately in setters 
        this.errorCode = errorCode; 
        this.errorMessage= new HashMap<>();  
    }

    public void addErrorMessage(String key, String value){
       if(this.errorMessage == null){
            this.errorMessage= new HashMap<>();   // in case you don't want to initialize the map in your constructor
       }
       this.errorMessage.put(key, value);          // there you go, just put any key value you like
    }
}

Answer 2

此结构非常适合您的用例：

public class Response {

private String errorCode;

// This is useful when you do not know what the keys could be
private Map<String, String> errorMessage;

// ...setters/getters below

}

用于表示 JSON 对象的通用 pojo

Generic pojo for representation of a JSON object

java

json

pojo