Question

我已经定义了JSON Pojo类，如下所示，在下面的MyMessage类中，有时我接收kpMessage类作为字符串，如何将接收到的字符串转换为object。

@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonPropertyOrder({ "kp.message", "kp.version" })
public class MyMessage {

    @JsonProperty("kp.message")
    private KpMessage kpMessage;
    @JsonProperty("kp.version")
    private String kpVersion;

    @JsonProperty("kp.message")
    public KpMessage getKpMessage() {
        return KpMessage;
    }

    @JsonSetter
    public void setKpMessage(KpMessage kpMessage) {
        this.kpMessage = kpMessage;
    }

    @JsonProperty("kp.version")
    public String getKpVersion() {
        return kpVersion;
    }

    @JsonProperty("kp.version")
    public void setKpVersion(String kpVersion) {
        this.kpVersion = kpVersion;
    }

}

KpMessage.java

@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonPropertyOrder({ "domain", "request_id", "auth_token"})
public class KpMessage {

    @JsonProperty("domain")
    private Object domain;
    @JsonProperty("request_id")
    private String requestId;
    @JsonProperty("auth_token")
    private String authToken;

    @JsonProperty("domain")
    public Object getDomain() {
        return domain;
    }

    @JsonProperty("domain")
    public void setDomain(Object domain) {
        this.domain = domain;
    }

    @JsonProperty("request_id")
    public String getRequestId() {
        return requestId;
    }

    @JsonProperty("request_id")
    public void setRequestId(String requestId) {
        this.requestId = requestId;
    }

    @JsonProperty("auth_token")
    public String getAuthToken() {
        return authToken;
    }

    @JsonProperty("auth_token")
    public void setAuthToken(String contextAuthToken) {
        this.authToken = authToken;
    }
}

以下示例输入按预期工作。

{  
   "kp.message":{  
      "domain":null,
      "request_id":"req-11ef0ffa-0180-4040-a47e-9f78b23b49e9",
      "auth_token":"gAAAA"
   },
   "kp.version":"2.0"
}

但是，以下输入失败，错误为no String-argument constructor/factory method to deserialize from String value

{
    "kp.message": "{
    \"domain\": null, 
    \"request_id\": \"req-11ef0ffa-0180-4040-a47e-9f78b23b49e9\", 
    \"auth_token\": \"gAAAA\",
    }", 
    "kp.version": "2.0"
}

如何为上述输入添加反序列化器，以便在收到字符串转义转义字符"时，字符串将转换为KpMessage对象

Answer 1

对于这个用例，我发现的一个解决方案是按照错误消息的建议进行操作，并创建一个带有单个字符串参数的构造函数；然后使用 Jackson 或 Gson 解析原始值。类似的东西：

public KpMessage(String json) throws IOException {
    KpMessage k = new ObjectMapper().readValue(json, KpMessage.class);
    this.domain = k.domain;
    this.requestId = k.requestId;
    this.authToken = k.authToken;
}

参考：Convert JSON String (Which includes different lenients) to Java Class with RestTemplate

另一种方法是使用 JsonDeserialize.

Jackson将原始json的属性值反序列化为object

1 个答案: