Deserialise Xml to List using Jackson failed

Roth :

Im trying to deserialise my Xml file and map it to my Class, it is working fine if I did not attach List to my class.

Ive already added static class,jsonIgnoreProperties, using XMLElementWrapper, but its still not working!

This is the method im calling.

File file = new File(test.xml);
XmlMapper xmlMapper = new XmlMapper();
String xml = inputStreamToString(new FileInputStream(file));

Test test = xmlMapper.readValue(xml, Test.class);

Here is my class.

import java.util.List;
import org.codehaus.jackson.annotate.JsonProperty;
import com.fasterxml.jackson.xml.annotate.JacksonXmlElementWrapper;
import com.fasterxml.jackson.xml.annotate.JacksonXmlRootElement;

@JacksonXmlRootElement(localName = "web-request-form")
public class Test {

@JsonProperty("attachments")
public Attachments attachments;

public Test(Attachments attachments) {
    super();
    this.attachments = attachments;
}

public Test() {
    super();
}

public Attachments getAttachments() {
    return attachments;
}

public void setAttachments(Attachments attachments) {
    this.attachments = attachments;
}

public static class Attachments {


    @JacksonXmlElementWrapper(localName = "attachment")
    public List<Attachment> attachment;

    public Attachments() {
        super();
    }

    public Attachments(List<Attachment> attachment) {
        super();
        this.attachment = attachment;
    }

    public List<Attachment> getAttachment() {
        return attachment;
    }

    public void setAttachment(List<Attachment> attachment) {
        this.attachment = attachment;
    }
}

public static class Attachment {

    @JsonProperty("filename")
    public String fileName;

    @JsonProperty("desc")
    public String desc;

    @JsonProperty("size")
    public String size;

    public Attachment() {
        super();
    }

    public Attachment(String fileName, String desc, String size) {
        super();
        this.fileName = fileName;
        this.desc = desc;
        this.size = size;
    }

    public String getFileName() {
        return fileName;
    }

    public void setFileName(String fileName) {
        this.fileName = fileName;
    }

    public String getDesc() {
        return desc;
    }

    public void setDesc(String desc) {
        this.desc = desc;
    }

    public String getSize() {
        return size;
    }

    public void setSize(String size) {
        this.size = size;
    }
}

}

Here is my xml file.

<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<!--This file was generated from an ASPX file-->
<web-request-form xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="WebRequestForm.elms.xmlbeans.novacitynets.com">
 <attachments>
  <attachment>
    <filename>test</filename>
    <desc />
    <size>2089.801</size>
  </attachment>
 </attachments>
</web-request-form>

This is the error im getting.

Can not instantiate value of type [simple type, class 
package.Test$Attachment] from JSON String; no single-String 
constructor/factory method (through reference chain: 
package.Test["attachments"]->package.Attachments["attachment"])

Madplay :

I'm not sure of your Jackson library version, but if you are using version 2.1 or later, Can you try this code below? Also, it seems not good to mix codehaus and fasterxml.

try the following:

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;

import java.util.List;

@JacksonXmlRootElement(localName = "web-request-form")
public class Test {
    @JsonProperty("attachments")
    public Attachments attachments;

    public static class Attachments {
        // @JacksonXmlElementWrapper(localName = "attachment")
        @JacksonXmlElementWrapper(useWrapping = false, localName = "attachment")
        public List<Attachment> attachment;

        // ...
    }

    public static class Attachment {
        @JsonProperty("filename")
        public String fileName;

        @JsonProperty("desc")
        public String desc;

        @JsonProperty("size")
        public String size;

        // ...
    }
}

If you have applied the useWrapping option to the JacksonXmlElementWrapperannotation, nothing will change. Call the method as follows:

File file = new File("test.xml");

// If you use the useWrapping option globally
// JacksonXmlModule module = new JacksonXmlModule();
// module.setDefaultUseWrapper(false);

XmlMapper xmlMapper = new XmlMapper(module);
String xml = inputStreamToString(new FileInputStream(file));
Test test = xmlMapper.readValue(xml, Test.class);