使用Jackson XML jar将XML数据转换为POJO？

Question

Am work on java project with XML data from another web-service. Am new to Jackson framework. Create the POJO file but while mapping it show error like Unrecognized field column. Don't know how to map my response

XML Response

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<CellSet>
    <Row key="MNg==">
        <Cell column="ZG9ybWFudF9kZXRhaW29u" timestamp="1563189660088">MjAQ==</Cell>
        <Cell column="ZG9yxzOkV5ZXBsdXM=" timestamp="1563189660088">RI0</Cell>
        <Cell column="ZG9ybWFudF9kZWxzOl=" timestamp="1563189660088"/>
        <Cell column="ZG9ybaWxzOlVDSUM=" timestamp="1563189660088">Mg==</Cell>
        <Cell column="ZG9ybWFudF9kZXRhYXRl" timestamp="1563189660088">MMQ==</Cell>
        <Cell column="ZG9ybWxzOlpveWE=" timestamp="1563189660088"/>
        <Cell column="ZzOndhdGNoZXM=" timestamp="1563189660088"/>
    </Row>
</CellSet>

CellSet Class

@JacksonXmlRootElement(localName = "CellSet")
public final class CellSet {

public CellSet() {}

@JacksonXmlElementWrapper(localName = "Row")
private Row[] rows;

public Row[] getRows() {
    return rows;
}

}

Row Class

public final class Row {

public Row() {}

@JacksonXmlElementWrapper(localName = "Cell")
private Cell[] cells;

public Cell[] getCells() {
    return cells;
}

}

Cell Class

public final class Cell {

public Cell() {
    // TODO Auto-generated constructor stub
}

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

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

public String getColumn() {
    return column;
}

public String getTimestamp() {
    return timestamp;
}
}

Help me to solve this issue.

Answer 1

First of all, looking at the xml document and the Java bean tree, I made the assumption that a response can have multiple Row elements under the CellSet root element.

So, given the above assumption, there are several problems with your object model. The first is the misuse of the @JacksonXmlElementWrapper . This annotation signifies that an array of XML elements is wrapped by a higer-hierarchy element. so when you write

@JacksonXmlElementWrapper(localName = "Row")
private Row[] rows;

jackson expects an input like this

<Row>  // xml wrapper
  <rows>  // xml array 
  <rows>
  <rows>
</Row>

in fact, you need to tell jackson that the row array is unwrapped like this

@JacksonXmlElementWrapper(useWrapping = false)
@JacksonXmlProperty(localName = "Row")
private Row[] rows;

and same for cell array.

the other problem is that Row class does not have a target for key attribute and Cell does not have a target for the text value of the cell element.
the complete solution is given below

@JacksonXmlRootElement(localName = "CellSet")
public class CellSet {

    @JacksonXmlElementWrapper(useWrapping = false)
    @JacksonXmlProperty(localName = "Row")
    public Row[] rows;
}

public class Row {

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

    @JacksonXmlElementWrapper(useWrapping = false)
    @JacksonXmlProperty(localName = "Cell")
    public Cell[] cells;
}

public class Cell {

    @JacksonXmlText()
    public String value;

    @JacksonXmlProperty(localName = "column", isAttribute = true)
    public String column;

    @JacksonXmlProperty(localName = "timestamp", isAttribute = true)
    public String timestamp;

}

last note: your classes are also missing setter methods (this is deserialization/unmarshalling, right?) in the above solution, all variables were made public for brevity