从本地主机导入列表时，人们如何修复反序列化错误？

Question

我正在尝试将我的 json 列表放入我的代码中，但我一直收到此错误。

at com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException.from(UnrecognizedPropertyException.java:61)
    at com.fasterxml.jackson.databind.DeserializationContext.handleUnknownProperty(DeserializationContext.java:840)
    at com.fasterxml.jackson.databind.deser.std.StdDeserializer.handleUnknownProperty(StdDeserializer.java:1206)
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperty(BeanDeserializerBase.java:1592)
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownVanilla(BeanDeserializerBase.java:1570)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:294)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:151)
    at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:286)
    at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:245)
    at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:27)
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4202)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3205)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3188)
    at dev.lightt.Application.main(Application.java:34)

我的密码是

   public static final String POSTS_API_URL = "http://localhost:3000/Leaders";

    public static void main(String[] args) throws IOException, InterruptedException {


        HttpClient client = HttpClient.newHttpClient();
        HttpRequest request = HttpRequest.newBuilder()
                .GET()
                .header("accept", "application/json")
                .uri(URI.create(POSTS_API_URL))
                .build();
        HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());

        // parse JSON
        ObjectMapper mapper = new ObjectMapper();
        List<Post> posts = mapper.readValue(response.body(), new TypeReference<>() {
        });
        posts.forEach(System.out::println)

我正在查看 restful API 教程，但它没有提到这一点。

我的Json有点像

{
         "UserId":1,
         "Id":1,
         "Title":"Life",
         "Body":"Man suffers only because he takes seriously what the gods made for fun."
      },
      {
         "UserId":1,
         "Id":2,
         "Title":"Nature",
         "Body":"Without birth and death, and without the perpetual transmutation of all the forms of life, the world would be static, rhythm-less, undancing, mummified."
      },

这是 Post Class 代码。它是说 getter 和 setter 没有被使用。唯一没有说明的是 getUserId()、getTitle() 和 getId()。

public class Post {

    private int id;
    private String title;
    private String body;
    private int userId;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getBody() {
        return body;
    }

    public void setBody(String body) {
        this.body = body;
    }

    public int getUserId() {
        return userId;
    }

    public void setUserId(int userId) {
        this.userId = userId;
 @Override
    public String toString() {
        return "Post{" +
                "id='" + id + '\'' +
                ", title='" + title + '\'' +
                '}';
    }
}
    }

Answer 1

映射区分大小写，因此您可以：

将您的 json 更改为

{
         "userId":1,
         "id":1,
         "title":"Life",
         "body":"Man suffers only because he takes seriously what the gods made for fun."
}

映射 POJO 中的属性

    @JsonProperty("Id")
    private int id;

    @JsonProperty("Title")
    private String title;

    @JsonProperty("Body")
    private String body;

    @JsonProperty("UserId")
    private int userId;

从本地主机导入列表时，人们如何修复反序列化错误？

How do people fix a deserialization error when importing a list from the localhost?

java

json

get

localhost

deserialization