There is a problem that using XMLMapper.getValue(InputStream,Map.class) to deserializing property list

Here is my maven dependency

    <dependency>
        <groupId>com.fasterxml.jackson.dataformat</groupId>
        <artifactId>jackson-dataformat-xml</artifactId>
        <version>2.3.2</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.3.2</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-annotations</artifactId>
        <version>2.3.2</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.3.2</version>
    </dependency>

Here is my xml file.

<?xml version="1.0" encoding="UTF-8"?>
<vendor>
    <location id="store101">
        <address>
            <province>S.T</province>
            <street>Orchard Road</street>
        </address>
    </location>

    <location id="store102">
        <address>
            <province>S.T</province>
            <street>Tangerine Drive</street>
        </address>
    </location>
</vendor>

and here is my java code

package com.jackson.test;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;







import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.DeserializationFeature;;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.dataformat.xml.JacksonXmlModule;
import com.fasterxml.jackson.dataformat.xml.XmlMapper;

import java.util.ArrayList;


public class UnitTest {

    public static void main(String[] args) {
        new UnitTest().testReadXmlToBean();
    }

    public void testReadXmlToBean() {
        JacksonXmlModule jacksonXmlModule = new JacksonXmlModule();
        jacksonXmlModule.setDefaultUseWrapper(false);
        ObjectMapper xmlMapper = new XmlMapper(jacksonXmlModule);

        InputStream is=null;
        String path="";
//      path="/META-INF/persistence.xml";
        path="/META-INF/Vendor.xml";
         is=this.getClass().getResourceAsStream(path);
        File file = new File(this.getClass().getResource(path).getPath());
        try {
            // JsonNode jsonNode=xmlMapper.readTree(is);
            Object obj= null;
//          obj = xmlMapper.readValue(is, Vendor.class);
//          obj = xmlMapper.readValue(is, List.class);
            obj = xmlMapper.readValue(is, Map.class);
            /*JsonNode jsonNode = xmlMapper.readTree(file);
            String value=jsonNode.path("persistence-unit[name]").asText();
            System.out.println(value);*/
            ObjectMapper jsonMapper = new ObjectMapper();
            String json = jsonMapper.writeValueAsString(obj);
            System.out.println(json);
        } catch (JsonParseException e) {
            e.printStackTrace();
        } catch (JsonMappingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            is.close();
        } catch (IOException e) {
        }
    }

}


class Vendor {
    private List<Location> location = new ArrayList<Location>();

    public List<Location> getLocation() {
        return location;
    }

    public void setLocation(List<Location> location) {
        this.location = location;
    }

}
class Location {
    private Adress address;
    private String id;

    public Adress getAddress() {
        return address;
    }

    public void setAddress(Adress address) {
        this.address = address;
    }

    public String getId() {
        return id;
    }

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

}
class Adress {
    private String province;
    private String street;

    public String getProvince() {
        return province;
    }

    public void setProvince(String province) {
        this.province = province;
    }

    public String getStreet() {
        return street;
    }

    public void setStreet(String street) {
        this.street = street;
    }

}

I tried all of this (see below).Only the first one can get the correct result.Why?

//1
obj = xmlMapper.readValue(is, Vendor.class);
//2
obj = xmlMapper.readValue(is, List.class);
//3
obj = xmlMapper.readValue(is, Map.class);
//4
JsonNode jsonNode = xmlMapper.readTree(file);

I don’t want to create bean class.How can I deserialize property list to a Map and List object?

[cowtowncoder]

The first reason is that you did not specify actual type of values for Map or List. Instead of List.class, you need to use something like

List<Location> list = xmlMapper.readValue(is, new TypeReference<List<Location>>() { });
// or:
static class LocationList extends ArrayList<Location> { }
LocationList list = xmlMapper.readValue(is, LocationList.class);

because otherwise you are just asking for List<Object>.

Map would not work since structure is not compatible with maps.

As to tree model (JsonNode); XML and JSON are structurally incompatible, and use of tree model is not fully supported with XML module. It does work for some cases but not all; so I generally suggest not using it with XML. There are XML-specific tree models (DOM, Dom4j, JDOM) that work better.

Hope this helps.

[cowtowncoder]

Ok no problem. This is just bit of a FAQ, I should write down better explanation. It is not at all unreasonable to wish for smoother handling; especially given that this works just fine for JSON. Unfortunately XML imposes more limitations.