Question

My enum class

@XmlType
@XmlEnum(Integer.class)
public enum  Error {

 @XmlEnumValue("1")
    ENUM_VALUE_1(1, "some string 1", "some string 1"),
 @XmlEnumValue("2")
    ENUM_VALUE_2(2, "some string 2", "some string 2");

  private Error(int errorCode, String msgKey, String message) {
    this.errorCode = errorCode;
    this.msgKey = msgKey;
    this.message = message;
 }
}

Generated xsd

<xs:simpleType name="error">
   <xs:restriction base="xs:int">
     <xs:enumeration value="1"/>
     <xs:enumeration value="2"/>
   </xs:restriction>
</xs:simpleType> 

binding I am using

 <jaxb:bindings schemaLocation="schema.xsd">
     <jaxb:bindings node="//xs:simpleType[@name='error']">
         <jaxb:typesafeEnumClass ref="packageName.Error" />
     </jaxb:bindings>
 </jaxb:bindings>

The problem is there is no enum file is getting generated. I am using “maven-jaxb2-plugin” for code generation.

Answer 1

By default a JAXB (JSR-222) implementation will not create a Java enum for XML enumerations that start with numeric values. You can use an external binding file to cause an enum to be generated.

<jxb:bindings 
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns:jxb="http://java.sun.com/xml/ns/jaxb"
    version="2.1">
    <jxb:bindings schemaLocation="schema.xsd">
        <jxb:bindings node="//xs:simpleType[@name='error']/xs:restriction/xs:enumeration[@value='1']">
            <jxb:typesafeEnumMember name="ONE"/>
        </jxb:bindings>
        <jxb:bindings node="//xs:simpleType[@name='error']/xs:restriction/xs:enumeration[@value='2']">
            <jxb:typesafeEnumMember name="TWO"/>
        </jxb:bindings>
    </jxb:bindings>
</jxb:bindings>

Full Example

• Enums don't match schema: problem with jaxb or xsd?

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UPDATE

Then what is the point of adding following annotation –
@XmlEnumValue(“1”)

In your start from Java classes use case you used the @XmlEnumValue("1") annotation to map your enum to the desired XML structure.

  <xs:simpleType name="error">
    <xs:restriction base="xs:int">
      <xs:enumeration value="1"/>
      <xs:enumeration value="2"/>
    </xs:restriction>
  </xs:simpleType>

JAXB implementations don’t generate JAXB information into the XML schema, so if someone wants to generate a Java model from the generated schema then a binding file can be used.