Question

我正在尝试为以下JSON结构创建POJO。 Fields节点很容易连线，但是我不确定如何使用注释来连线Description节点。如果我已经为该节点定义了JSON结构，那么我将创建一个JsonObjects的JsonArray，这将使Java类变得容易，但是由于我没有这么做，所以我需要弄清楚如何序列化以下结构： / p>

{
    "Fields": {
        "Required": ["ftp.hostname"],
        "Optional": ["ftp.rootDirectory"]
    },
    "Description": {
        "ftp.hostname": {
            "label": "SFTP Hostname",
            "description": "SFTP server hostname or IP address"
        },
        "ftp.rootDirectory": {
            "label": "Root Directory",
            "description": "The root path on the Data Store accessible by this connector"
        }
    }
}

请注意，Description对象中的节点的名称与Fields节点中定义的值相关，这意味着它们的节点名称可能因有效负载而异。

Fields节点的类：

public class FieldDetails {

    public static final String REQUIRED = "Required";
    public static final String OPTIONAL = "Optional";

    @JsonProperty(value = REQUIRED, required = true)
    private List<String> required;

    @JsonProperty(value = OPTIONAL, required = true)
    private List<String> optional;
}

到目前为止，我对整个对象的了解是

public class FieldDefinitions {

    public static final String FIELDS = "Fields";
    public static final String DESCRIPTION = "Description";

    @JsonProperty(value = FIELDS, required = true)
    private FieldDetails fields;

    @JsonProperty(value = DESCRIPTION , required = true)
    private ??? descriptions;
}

Answer 1

那是结构。

phrase = ("""<d:entry xmlns:d="http://www.apple.com/DTDs/DictionaryService-1.0.rng" id="test" d:title="test">
          """<d:index d:value="test" d:title="test"/><d:index d:value="test2" d:title="test2"/>"""
          """<div class="ODECN"><div class="extras"><div class="phrase"><span class="word_title"><i>test</i></span>:
          """</d:entry>""")

Answer 2

通常，您始终可以将任何JSON对象映射到Map<String, Object>。如果JSON包含许多嵌套对象，则Jackson将自动选择正确的类型：Map用于对象，List用于数组。

您还可以为Description属性声明如下的类。

class Description {
    private String label;
    private String description;
    // getters, setters, toString
}

整个Description是一个很大的JSON，您可以将其映射到Map<String, Description>。因此，它可能如下所示：

class FieldDefinitions {

    public static final String FIELDS = "Fields";
    public static final String DESCRIPTION = "Description";

    @JsonProperty(value = FIELDS, required = true)
    private FieldDetails fields;

    @JsonProperty(value = DESCRIPTION, required = true)
    private Map<String, Description> descriptions;

    // getters, setters, toString
}

其余部分相同。示例应用程序：

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.File;
import java.util.List;
import java.util.Map;

public class JsonApp {

    public static void main(String[] args) throws Exception {
        File json = new File("./resource/test.json").getAbsoluteFile();

        ObjectMapper mapper = new ObjectMapper();

        FieldDefinitions fields = mapper.readValue(json, FieldDefinitions.class);
        System.out.println("Required");
        fields.getFields().getRequired().forEach(r ->
                System.out.println(r + " = " + fields.getDescriptions().get(r)));
        System.out.println("Optional");
        fields.getFields().getOptional().forEach(r ->
                System.out.println(r + " = " + fields.getDescriptions().get(r)));
    }
}

对于给定的JSON payload打印：

Required
ftp.hostname = Description{label='SFTP Hostname', description='SFTP server hostname or IP address'}
Optional
ftp.rootDirectory = Description{label='Root Directory', description='The root path on the Data Store accessible by this connector'}

如何为JsonObjects的JsonObject创建Jackson XML POJO类

2 个答案: