Generation of XSD restrictions in a schema generated from Java JAXB annotated classes

问题

MOXy BeanValidation gives me the ability to add validation to my JAXB classes.

Using MOXy's "Bean Validation Plugin" I can have Bean Validation in generated JAXB classes based on restrictions/facets from a prexisting Schema.

However is there any way of generating a schema with restrictions/facetsbased on Bean Validation annotations from a JAXB annotated java class?

XJC has a handy plugin architecture when doing 'schema first' generating java, but is there any equivalent 'java first' way to enhance the generated XSD with additional restrictions, or even to add XML comments ? Either in MOXy or JAXB-RI?

MOXy is extremely flexible with meet in the middle mappings, can this be used during schema generation?

The jaxb-facets project seems to do what I want but the implementer had to fork an entire new JAXB-RI to get it in and it seems that it won't be adopted any time soon.(See this Java JIRA)

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I tried the resolution specified by @m0mus but had to use the 2.7.0-SNAPSHOT versions from the sonatype repository. I still had a couple of problems; 1. I had to annotate the java fields with @XmlElement to get the facets to appear in the xsd. @XmlAttribute, @XmlAccessorType(XmlAccessType.FIELD) made no difference. @Pattern did not work; I had to work around with a single Pattern in Pattern.List;

@XmlElement
@Pattern.List(value = { @Pattern(regexp="[0-9]*") })
public String phoneNumber2;

For more info see the EclipseLink Forum

回答1:

I think it is there. MOXy uses its own SchemaGen implementation for the process of generating XSD files from Java classes. SchemaGen was extended to automatically generate XSD Restrictions and Facets based on BV annotations found on Java classes. Since the schema generation process takes place upon creation of JAXBContext, the BV enhancement feature can be turned on/off by setting the following property (found in JAXBContextProperties) on JAXBContext:

/**
 * Property for disabling/enabling generation of XML Facets during schemagen.
 * The mapped value must be of type Boolean.
 * If it's true, then facets will be generated, based on the BV annotations.
 * If false, the BV annotations processing will be skipped during schemagen
 * and no facets will be generated.
 *
 * @since 2.6
 */
public static final String GENERATE_FACETS = "eclipselink.generate.facets";

SchemaGen recognizes annotations provided by the BV API, including @Pattern.List. If SchemaGen encounters a field annotated with both @NotNull and @XmlElement(nillable = true), it will raise the BeanValidationException.notNullAndNillable().

Sample:

Map props = new HashMap( );
props.put("eclipselink.beanvalidation.facets", true);
JAXBContext jc = JAXBContext.newInstance(classes, properties);
SchemaOutputResolver sor = new MSOR();
jc.generateSchema(sor);

回答2:

Filed a request for enhancement to process @XMLAttribute fields: Bugs Page

The reason you need to use v2.7 is that in some unusual call trees for schema generation, the enable facets property value is not propagated down the call tree. It was fixed on May 5th. Asked for backport to EL v2.6 now.

回答3:

You could also look to xjc plugin https://github.com/krasa/krasa-jaxb-tools

By documentation it support XJsr303Annotations and can generate:

• @Valid annotation for all complex types, can be further restricted to generate only for types from defined schema: -XJsr303Annotations:targetNamespace=http://www.foo.com/bar
• @NotNull annotation for objects that has a MinOccur value >= 1 or for attributes with required use
• @Size for lists that have minOccurs > 1
• @Size if there is a maxLength or minLength or length restriction
• @DecimalMax for maxInclusive restriction
• @DecimalMin for minInclusive restriction
• @DecimalMax for maxExclusive restriction, enable new parameter (inclusive=false) with: -XJsr303Annotations:JSR_349=true
• @DecimalMin for minExclusive restriction, enable new parameter (inclusive=false) with: -XJsr303Annotations:JSR_349=true
• @Digits if there is a totalDigits or fractionDigits restriction.
• @Pattern if there is a Pattern restriction

If you wonder how to use XJC plugins in your build environment (ant, maven, gradle) I may recomment look at examples of another plugin: immutable-xjc

So I hope it helps.

来源：https://stackoverflow.com/questions/32403146/generation-of-xsd-restrictions-in-a-schema-generated-from-java-jaxb-annotated-cl