Jackson XmlMapper读取XML文档，但生成null

Question

Java 1.8

Maven片段：

<dependency>
<groupId>com.fasterxml.jackson.dataformat</groupId>
<artifactId>jackson-dataformat-xml</artifactId>
<version>2.11.2</version>
</dependency>

snipped.xml

<?xml version="1.0" standalone="no"?>
<ledesxml_snipped>
<lede_name>Fitzhume</lede_name>
<firm>
<lf_tax_id>999999999</lf_tax_id>
<lf_id>Cogswell Cogs</lf_id>
<lf_name>Cogswell Cogs, Inc.</lf_name>
<lf_address>
<address_info>
<address_1>404 Asteroid Drive</address_1>
<address_3>Suite 2600</address_3>
<city>Dallas</city>
<state_province>TX</state_province>
<zip_postal_code>75203</zip_postal_code>
<country>USA</country>
</address_info>
</lf_address>
<lf_billing_contact_phone>2145551212</lf_billing_contact_phone>
<lf_billing_contact_fax>2148761234</lf_billing_contact_fax>
<lf_billing_contact_email>[e-mail]</lf_billing_contact_email>
<source_app>AimPoint</source_app>
<app_version>
</app_version>
</firm>
</ledesxml_snipped>

LedesSnipped.java

package com.my.application.model;
import java.io.*;
import java.util.*;
import javax.xml.bind.annotation.*;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlElementWrapper;
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "", propOrder = {
"ledeName",
"firm"
})
@XmlRootElement(name = "ledesxml_snipped")
public class LedesxmlSnipped {
@XmlElement(name = "lede_name", required = true)
protected String ledeName;
@XmlElement(required = true)
@JacksonXmlElementWrapper( useWrapping = false)
protected LedesxmlSnipped.Firm firm;

public String getLedeName() {
return ledeName;
}

public void setLedName( String ledeName) {
this.ledeName = ledeName;
}
public LedesxmlSnipped.Firm getFirm() {
return firm;
}
public void setFirm(LedesxmlSnipped.Firm value) {
this.firm = value;
}

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "", propOrder = {
"lfTaxId",
"lfId",
"lfName",
"lfAddress",
"lfBillingContactPhone",
"lfBillingContactFax",
"lfBillingContactEmail",
"sourceApp",
"appVersion"
})
public static class Firm {
@XmlElement(name = "lf_tax_id")
protected int lfTaxId;
@XmlElement(name = "lf_id", required = true)
protected String lfId;
@XmlElement(name = "lf_name", required = true)
protected String lfName;
@XmlElement(name = "lf_address", required = true)
@JacksonXmlElementWrapper( useWrapping = false)
protected Ledesxml.Firm.LfAddress lfAddress;
@XmlElement(name = "lf_billing_contact_phone")
protected long lfBillingContactPhone;
@XmlElement(name = "lf_billing_contact_fax")
protected long lfBillingContactFax;
@XmlElement(name = "lf_billing_contact_email", required = true)
protected String lfBillingContactEmail;
@XmlElement(name = "source_app", required = true)
protected String sourceApp;
@XmlElement(name = "app_version", required = true)
protected String appVersion;
public int getLfTaxId() {
return lfTaxId;
}
public void setLfTaxId(int value) {
this.lfTaxId = value;
}
public String getLfId() {
return lfId;
}
public void setLfId(String value) {
this.lfId = value;
}
public String getLfName() {
return lfName;
}
public void setLfName(String value) {
this.lfName = value;
}
public Ledesxml.Firm.LfAddress getLfAddress() {
return lfAddress;
}
public void setLfAddress(Ledesxml.Firm.LfAddress value) {
this.lfAddress = value;
}
public long getLfBillingContactPhone() {
return lfBillingContactPhone;
}
public void setLfBillingContactPhone(long value) {
this.lfBillingContactPhone = value;
}
public long getLfBillingContactFax() {
return lfBillingContactFax;
}
public void setLfBillingContactFax(long value) {
this.lfBillingContactFax = value;
}
public String getLfBillingContactEmail() {
return lfBillingContactEmail;
}
public void setLfBillingContactEmail(String value) {
this.lfBillingContactEmail = value;
}
public String getSourceApp() {
return sourceApp;
}
public void setSourceApp(String value) {
this.sourceApp = value;
}
public String getAppVersion() {
return appVersion;
}
public void setAppVersion(String value) {
this.appVersion = value;
}
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "", propOrder = {
"addressInfo"
})
public static class LfAddress {
@XmlElement(name = "address_info", required = true)
protected Ledesxml.Firm.LfAddress.AddressInfo addressInfo;
public Ledesxml.Firm.LfAddress.AddressInfo getAddressInfo() {
return addressInfo;
}
public void setAddressInfo(Ledesxml.Firm.LfAddress.AddressInfo value) {
this.addressInfo = value;
}

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "", propOrder = {
"address1",
"address3",
"city",
"stateProvince",
"zipPostalCode",
"country"
})
public static class AddressInfo {
@XmlElement(name = "address_1", required = true)
protected String address1;
@XmlElement(name = "address_3", required = true)
protected String address3;
@XmlElement(required = true)
protected String city;
@XmlElement(name = "state_province", required = true)
protected String stateProvince;
@XmlElement(name = "zip_postal_code")
protected int zipPostalCode;
@XmlElement(required = true)
protected String country;
public String getAddress1() {
return address1;
}
public void setAddress1(String value) {
this.address1 = value;
}
public String getAddress3() {
return address3;
}
public void setAddress3(String value) {
this.address3 = value;
}
public String getCity() {
return city;
}
public void setCity(String value) {
this.city = value;
}
public String getStateProvince() {
return stateProvince;
}
public void setStateProvince(String value) {
this.stateProvince = value;
}
public int getZipPostalCode() {
return zipPostalCode;
}
public void setZipPostalCode(int value) {
this.zipPostalCode = value;
}
public String getCountry() {
return country;
}
public void setCountry(String value) {
this.country = value;
} 
}
}
}
}

最后，TryThis.java

package com.my.application;
import java.util.*;
import java.io.*;
import java.time.*;
import java.time.format.*;
import javax.xml.stream.*;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.dataformat.xml.*;
import com.my.application.model.*;
public class TryThis {
public static void main(String[] args) {
XmlMapper mapper = new XmlMapper();
mapper.enable( SerializationFeature.INDENT_OUTPUT);
mapper.disable( DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);

try {
File innFile = new File("snipped.xml");
LedesxmlSnipped asfda = mapper.readValue(innFile, LedesxmlSnipped.class);
System.out.println( "ledeName=" + asfda.getFirm().getLedeName());
} catch (JsonParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JsonMappingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

这一切的结果只是

ledeName=null

我希望在哪里看到

ledeName=Fitzhume

没有错误。那么我错过了什么？某种极其微妙的配置？我是否在错误的位置定义了XmlMapper？我看过的许多例子跨越了Jackson的各个版本，其中一些可以追溯到使用javax.xml.

Answer 1

只需添加

import com.fasterxml.jackson.module.jaxb.JaxbAnnotationModule;

和

mapper.registerModule( new JaxbAnnotationModule());

TryThis.java成功了。确实存在极其微妙的配置问题！

感谢所有读过这个问题的人。