Develop Reference

Unmarshalled object is null if namespace prefix is not set

I have the following XSD:
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:x="MY_NAMESPACE"
targetNamespace="MY_NAMESPACE">
<xs:element name="response" type="x:responseType"/>
<xs:complexType name="responseType">
<xs:all>
<xs:element name="param" type="x:responseParam"/>
</xs:all>
</xs:complexType>
<xs:complexType name="responseParam">
<xs:all>
<xs:element name="value" type="xs:string"/>
</xs:all>
</xs:complexType>
</xs:schema>
I use it to generate JAXB classes for unmarshalling a payload like the following:
<x:response xmlns:x="MY_NAMESPACE">
<param>
<value>OK</value>
</param>
</x:response>
via getWebServiceTemplate().marshalSendAndReceive in Spring. Problem is, I also want to unmarshal payloads without the namespace prefix, like this:
<response xmlns="MY_NAMESPACE">
<param>
<value>OK</value>
</param>
</response>
In this case, the response tag is parsed correctly, but the object reference representing param is always null. How can I edit my XSD to make things work? I already tried setting elementFormDefault="qualified" in the schema, or even form="qualified" on the param element.
Additional info that comes to mind (I might edit and add more depending on comments):
The unmarshaller is a Jaxb2Marshaller.

The XML documents
I think you probably know this, but removing that namespace prefix affects the entire document (because the 'param' and 'value' tags do not have any prefix and therefore inherit the default namespace binding). Becauses of this, in the first document the root tag 'response' is in namespace 'MY_NAMESPACE' and the other tags do not have any namespace. In the second document, all of the tags are in namespace 'MY_NAMESPACE'.
The XML Schema
The elementFormDefault attribute defaults to 'unqualified' so your schema should match the first document and reject the second. Your experiments confirm this.
If you set elementFormDefault to 'qualified' then it will reject the first document and match the second one.
There is no value of elementFormDefault that will make the XSD match both XML documents. The namespace is an integral part of the identity of the element.
Possible solution
If you are determined to construct an XSD that matches both documents then it could be done as follows:
explicitly set elementFormDefault to 'unqualified' (optional, but you're about to rely on that setting)b
wrap the current (globally-declared) contents of responseType in a choice group
add a second branch in the choice group containing a local declaration of element 'param' and all of its descendants. Because those are locally declared, they will be in noTargetNamespace.
This is not a general solution to the problem of making JAXB ignore namespaces, and I don't think you will find one (although I'm happy to be corrected by somebody who knows more than I do about JAXB).
Having said all of the above...I think you are probably solving the wrong problem. The JAXB standard is based on XML Schema. An XSD is not meant to tolerate the wrong namespaces. The second XML document is therefore invalid, and should be corrected by whoever is generating it.

How to accept xsd vs xml validation when elements having null values

I have a xml and have to validate against xsd for the structure and data type. but Some fields in the xml has null/empty values. But when using JAXB for validating the xml
"cvc-datatype-valid.1.2.1: '' is not a valid value for 'integer'."
This exception is thrown from JAXB exception with linked SaxParserError Exception. But I have to accept the xml with null values. These threads
validating an XML schema with empty attributes and Element type(long) without content shows we have to modify the xml with respect to xsd such that it should accept the null/empty values.
Is there any other way that I can override the methods of ValidationHandler class and Unmarshaller class to accept null values.

Well I guess you tried to put
<myinteger></myinteger>
in your XML but have an XSD like:
<element name="myinteger" type="integer" />
or
<element minOccurs="0" name="myinteger" type="integer" />
JAXB is right. In terms of XSD validation, this is wrong so you either have to change the XML, change the XSD, or disable validation (will still be wrong but won't crash). MinOccurs="0" means it is accepted that the element is not present at all (remove all the myinteger tags). It doesn't mean that a tag with empty content is accepted. The content must be integer. Empty string is not an integer.
Setting nillable = true doesn't work either. It means that this would be accepted :
<myinteger xsi:nil="true"></myinteger>
But you have to add this xsi:nil="true".
If you do want to accept this:
<myinteger></myinteger>
You can change your XSD as below:
<element name="myinteger" type="IntegerOrNothing" />
<xsd:simpleType name="IntegerOrNoting">
<xsd:union memberTypes="xsd:integer">
<xsd:simpleType>
<xsd:restriction base="xsd:string">
<xsd:enumeration value="" />
</xsd:restriction>
</xsd:simpleType>
</xsd:union>
</xsd:simpleType>
If you generate your beans from the XSD with Jaxb, fields of this type will be of type String by default. You will then need to use custom bindings to get Integer fields.

Can one teach JAXB to generate Java classes including comments? [duplicate]

I'm currently working with an XML Schema that has <xsd:annotation>/<xsd:documentation> on most types and elements. When I generate Java Beans from this XML Schema, then the Javadoc of those Beans only contains some generic generated information about the allowed content of the type/element.
I'd like to see the content of the <xsd:documentation> tag in the relevant places (for example the content of that tag for a complextType should show up in the Javadoc of the class generated to represent that complexType).
Is there any way to achieve this?
Edit: this XML Schema will be used in a WSDL with JAX-WS, so this tag might be appropriate as well.
Edit 2: I've read about <jxb:javadoc>. From what I understand I can specify that either in a separate JAXB binding file or directly in the XML Schema. That would almost solve my problem. But I'd rather use the existing <xsd:documentation> tag, since Javadoc is not the primary target of the documentation (it's information about the data structure primarily and not about the Java Beans generated from it) and to allow non-JAXB tools to access the information as well. Providing the documentation in both <jxb:javadoc> and xsd:documentation> "feels" wrong, because I'm duplicating data (and work) for no good reason.
Edit 3: Thanks to the answer by Pascal I realized that I already have half a solution: The <xsd:documentation> of complexTypes is written to the beginning of its Javadoc! The problem is still that only that complexTypes is used and simpleTypes (which can also result in a class) and elements are still Javadoc-less.

I've never been able to get regular xsd:documentation to be placed in the java source except if and only if it was a Complex Type. Documentation for elements, simple types,
etc are ignored.
So, I end up using jxb:javadoc. To do so, include the definition of xmlns:jxb="http://java.sun.com/xml/ns/jaxb" in your <xsd:schema> element.
Add a child to <xsd:complexType> or <xsd: element> or <xsd:attribute>:
<xsd:annotation><xsd:appinfo><jxb:XXX><jxb:javadoc>
This is my comment for a class/property
</jxb:javadoc></jxb:XXX></xsd:appinfo></xsd:annotation>
Where XXX is either "class" or "property".
For a package you write a child to xsd:schema
<xsd:annotation><xsd:appinfo><jxb:schemaBindings><jxb:package name="com.acme"><jxb:javadoc>
This is my comment for a package
</jxb:javadoc></jxb:package></jxb:schemaBindings></xsd:appinfo></xsd:annotation>
Writing HTML document requires bracketing with <![CDATA[ --- ]]>
(EDIT: While writing my answer, the question has been edited by the OP so I'm updating it accordingly)
In my case, javadoc was the only target so it was acceptable to use jxb:javadoc. But your update makes perfect sense and, actually, I totally agree with you. Sadly, I never found an ideal solution for the situation you describe (so I'll follow this question very carefully). Maybe you could use something like xframe to generate documentation from xsd:documentation, but this doesn't answer the question.

This just isn't possible with the JAXB reference implementation. Even if you were to try to write an XJC plugin, you'd find that the plugin API is given no reference to the Schema definition, so there's no way to extract this information.
Our only hope is that a future version of JAXB fixes the situation. There's an open feature request here.

I find the following techniques work pretty well for adding JavaDoc headers to Java element classes (generated from XML schemas). I nest the JavaDoc in tags defined in the jax-b namespace, nested within the xml schema annotation and appinfo tags. Note the jaxb namespace defines types of documentation tags; I use two of there: the class and the property tags. defined in the following namespace: xmlns:jxb="http://java.sun.com/xml/ns/jaxb"
1) To document a class, I use a jaxb "class" tag in the following sequence:
<xs:complexType name="Structure">
<xs:annotation>
<xs:appinfo>
<jxb:class>
<jxb:javadoc>
Documentation text goes here. Since parsing the schema
into Java involves evaluating the xml, I escape all
the tags I use as follows <p> for <p>.
</jxb:javadoc>
</jxb:class>
</xs:appinfo>
</xs:annotation>
.
.
.
</xs:complexType>
2) To document an element, I use the "property" tag as follows:
<xs:element name="description" type="rep:NamedString">
<xs:annotation>
<xs:appinfo>
<jxb:property>
<jxb:javadoc>
<p>Documentation goes here.</p>
</jxb:javadoc>
</jxb:property>
</xs:appinfo>
</xs:annotation>
</xs:element>
3) I use the same set of tags to document attributes:
<xs:attribute name="name" type="xs:NCName" use="required">
<xs:annotation>
<xs:appinfo>
<jxb:property>
<jxb:javadoc>
<p>Documentation goes here.</p>
</jxb:javadoc>
</jxb:property>
</xs:appinfo>
</xs:annotation>
</xs:attribute>
4) To document a choice, I use the property jaxb tag, and I document the choice.
<xs:choice maxOccurs="unbounded">
<xs:annotation>
<xs:appinfo>
<jxb:property>
<jxb:javadoc>
<p>Documentation goes here.</p>
</jxb:javadoc>
</jxb:property>
</xs:appinfo>
</xs:annotation>
<xs:element name="value" type="rep:NamedValue" />
<xs:element name="list" type="rep:NamedList" />
<xs:element name="structure" type="rep:NamedStructure" />
</xs:choice>
Attempting to document the individual choices here would fail, since this tag
produces an untyped list.

Especially for that case I wrote XJC plugin xjc-documentation-annotation-plugin.
What it does: <annotation><documentation> -> Java class annotations
Said we have this object described in XSD:
<xs:complexType name="CadastralBlock">
<xs:annotation>
<xs:documentation>Cadastral quarter</xs:documentation>
</xs:annotation>
<xs:sequence>
<xs:element name="number" type="xs:string">
<xs:annotation>
<xs:documentation>Cadastral number</xs:documentation>
</xs:annotation>
</xs:element>
</xs:complexType>
We run xjc like:
xjc -npa -no-header -d src/main/generated-java/ -p xsd.generated scheme.xsd
And got class like (getters, setters and any annotations omitted for simplicity):
public class CadastralBlock {
protected String number;
}
But in my case I want known how to class and fields was named in source file! So it what this plugin do!
So you get:
#XsdInfo(name = "Cadastral quarter", xsdElementPart = "<complexType name=\"CadastralBlock\">\n <complexContent>\n <restriction base=\"{http://www.w3.org/2001/XMLSchema}anyType\">\n <sequence>\n <element name=\"number\" type=\"{http://www.w3.org/2001/XMLSchema}string\"/></sequence>\n </restriction>\n </complexContent></complexType>")
public class CadastralBlock {
#XsdInfo(name = "Cadastral number")
protected String number;
}
How to use
Manual call in commandline
If you want run it manually ensure jar class with plugin in run classpath and just add option -XPluginDescriptionAnnotation. F.e.:
xjc -npa -no-header -d src/main/generated-java/ -p xsd.generated -XPluginDescriptionAnnotation scheme.xsd
Call from Java/Groovy
Driver.run(
[
'-XPluginDescriptionAnnotation'
,'-d', generatedClassesDir.absolutePath
,'-p', 'info.hubbitus.generated.test'
,'CadastralBlock.xsd'
] as String[]
,new XJCListener() {...}
)
See test XJCPluginDescriptionAnnotationTest for example.
Use from Gradle
With gradle-xjc-plugin:
plugins {
id 'java'
id 'org.unbroken-dome.xjc' version '1.4.1' // https://github.com/unbroken-dome/gradle-xjc-plugin
}
...
dependencies {
xjcClasspath 'info.hubbitus:xjc-documentation-annotation-plugin:1.0'
}
// Results by default in `build/xjc/generated-sources`
xjcGenerate {
source = fileTree('src/main/resources') { include '*.xsd' }
packageLevelAnnotations = false
targetPackage = 'info.hubbitus.xjc.plugin.example'
extraArgs = [ '-XPluginDescriptionAnnotation' ]
}
Complete gradle example in example-project-gradle directory of project.

Read XML with XSD schema in java (android)

I am receiving a XML string from a webserver that contains a XSD schema-definition in the beginning looking like this:
...
<xs:sequence>
<xs:element name="" .../>
<xs:element name="" .../>
...
</xs:sequence>
...
The attribute name defines the tags of a dataset in the xml part of the string that is underneath the schema-definition, looking like this:
...
<DataSet id="DataSet1">
<name1>value</name1>
<name2>value</name2>
...
</DataSet>
<DataSet id="DataSet2">
<name1>value</name1>
<name2>value</name2>
...
</DataSet>
...
Can someone give me an advice how to parse this.
PS: The number of elements defining the names is variable and can be different everytime so these tags are not static.

I guess that you don't just want to parse it, you also want to process it after parsing (unfortunately this misuse of the word "parse" is becoming endemic). Parsing should be trivial assuming that the file as a whole is well-formed XML (which you haven't said). Processing depends entirely on what you want to do with the data. For example, some kinds of processing might need the schema information, other kinds might not.

JAXB multiple schemas with element reference

I have two schemas which are processed using JAXB. The first schema is preprocessed and information of this is used using an episode file (following http://www.java.net/blog/2006/09/05/separate-compilation-jaxb-ri-21).
The second schema imports the first, and again using jaxb, is processed. This all works as expected.
But now I have an element in the first schema, which is used in the second using a reference.
Schema a:
<schema elementFormDefault="qualified" xmlns="http://www.w3.org/2001/XMLSchema"
xmlns:test="http://www.example.org/Test/"
targetNamespace="http://www.example.org/Test/">
<element name="type" type="test:MyType"></element>
Schema b:
<schema elementFormDefault="qualified"
xmlns="http://www.w3.org/2001/XMLSchema"
xmlns:second="http://www.example.org/Second/"
xmlns:test="http://www.example.org/Test/"
targetNamespace="http://www.example.org/Second/">
<import namespace="http://www.example.org/Test/" />
<complexType name="SomeType">
<sequence>
<element ref="test:type" minOccurs="1" maxOccurs="unbounded" />
</sequence>
</complexType>
During processing nothing is wrong, but the generated code for both schemas provide the same method:
public JAXBElement<EventType> createType(TypeType value)
At runtime, this results in the following error:
com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException: 1 counts of
IllegalAnnotationExceptions
The element name {http://www.example.org/Type/}type has more than one mapping.
How can I prevent JAXB from creating the duplicate createType methods?
Thanks in advance!
Update: I asked this same question on the JAXB mailing list, on that list I also posted a working example. The thread and example can be found at: http://java.net/projects/jaxb/lists/users/archive/2011-03/message/18
On this list I've been suggested a workaround, and now I can use the schemas the way I like. But I still think JAXB should not create the additional "create" method, since it should already be in the episode file.

I've written a few Schema Definitions in my day. You are declaring your first xsd in your second schema declaration and then you are importing it.
As per MSDN, when you import an XSD you do not include it in the Schema Declaration.
This is where it is in your schema declaration.
xmlns:test="http://www.example.org/Test/"
Remove this and just do the import... ( <xs:import namespace="http://www.example.com/IPO" /> )
see:http://msdn.microsoft.com/en-us/library/ms256480.aspx