Deserialize XML containing Properties and Values with Jackson

Question

I'm trying to deserialize the following XML.

<RESPONSE>
    <FIELDS>
        <FIELD KEY="MSG_VERSION">003</FIELD>
        <FIELD KEY="CUSTOMER_NBR">001</FIELD>
        ...
        <FIELD KEY="ORIGINAL_TYPE">RM1</FIELD>
    </FIELDS>
</RESPONSE>

I need to capture the values from KEY properties and the values. Following is the Java class I have created.

package io.app.domain;

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlElementWrapper;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlText;
import lombok.Data;

import java.util.ArrayList;
import java.util.List;

@Data
@JsonInclude(JsonInclude.Include.NON_NULL)
@JacksonXmlRootElement(localName = "RESPONSE")
public class ResponseData {
    @JacksonXmlElementWrapper(localName = "FIELDS")
    @JacksonXmlProperty(localName = "FIELD")
    private List<Field> fields = new ArrayList<>();
    @Data
    public static class Field {
        @JacksonXmlProperty(isAttribute = true)
        private String key;
        @JacksonXmlText(value = true)
        private String content;
    }
}

The XmlMapper has been initialized as follows.

private final XmlMapper xmlMapper = new XmlMapper();

xmlMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
xmlMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);

The issue is that, although the content is properly getting set, the key value is always null. What am I doing wrong here?

Could be a case of case-differences, i.e. the field `key` might be interpreted as attribute `Key` which is different from `KEY`. — Thomas, Feb 14 '22 at 07:52

score 1 · Answer 1 · answered Feb 14 '22 at 07:59

1

As @Thomas pointed out in a comment on the post, it was the case of the property that was causing the issue.

@JacksonXmlProperty(isAttribute = true, localName = "KEY")
private String key;

This was the fix.

answered Feb 14 '22 at 07:59

Nimila Hiranya

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smilyface · Answer 2 · 2022-02-14T12:15:18.063

Or you can have like below. (I haven't tried). More readable.

@JacksonXmlRootElement(localName = "RESPONSE")
class ResponseFields {

    @JacksonXmlProperty(localName = "FIELDS")
    @JacksonXmlElementWrapper(useWrapping = false)
    private Fields[] fields;

    //getters, setters, toString
}


class Fields {
    @JacksonXmlProperty(localName = "FIELD")
    private Field[] field;

    //getters, setters, toString
}

class Field {
    @JacksonXmlProperty(isAttribute = true)
    private String key;
    @JacksonXmlText(value = true)
    private String value;

    //getters, setters, toString
}

And then;

XmlMapper mapper = new XmlMapper();
ResponseFields responseFields = mapper.readValue(XML, ResponseFields.class);
System.out.println(responseFields);

Deserialize XML containing Properties and Values with Jackson

2 Answers2