在 JPA/JAX-RS Web 服务中验证 JAXBElement

2022-01-19 00:00:00 validation java jaxb eclipselink jersey

我有一个 JAX-RS Web 服务 (Jersey)，它是 JPA (EclipseLink) 实体的 CRUD 接口.我的实体是从数据库表中自动生成的，并且我使用 JAXB 注释对它们进行了注释，以便可以将它们编组/解组到 XML.我的资源方法在需要时将 JAXBElement 对象作为参数.

I have a JAX-RS webservice (Jersey) that is a CRUD interface for JPA (EclipseLink) entities. My entities were autogenerated from the database tables and I have annotated them with JAXB annotations so that they can be marshalled/unmarshalled to/from XML. My resource methods take JAXBElement objects as a parameter where required.

我没有 XSD，但是，我愿意编写一个来验证请求中收到的 XML.但是，我不知道如何启动验证.Jersey 会自动处理编组/解组，并且我发现的有关验证的任何参考都是在该级别完成的.

I don't have an XSD, however, I'm willing to write one to validate the XML received in the requests. But, I don't know how to initiate the validation. Jersey is automatically handling the marshalling/unmarshalling and any references I've found about validation is done at that level.

有人知道说明如何执行此操作的示例/教程吗?

Does someone know of an example/tutorial that shows how to do this?

谢谢！

推荐答案

您可以通过创建自定义 MessageBodyReader 来处理这个问题.下面的示例基于 Customer 模型:

You could handle this by creating a custom MessageBodyReader. The example below is based on a Customer model:

import java.io.IOException;
import java.io.InputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.net.URL;

import javax.ws.rs.Consumes;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.ContextResolver;
import javax.ws.rs.ext.MessageBodyReader;
import javax.ws.rs.ext.Provider;
import javax.ws.rs.ext.Providers;
import javax.xml.XMLConstants;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;

@Provider
@Consumes("application/xml")
public class ValidatingReader implements MessageBodyReader<Customer> {

    @Context
    protected Providers providers;

    private Schema schema;

    public ValidatingReader() {
        try {
            SchemaFactory sf = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
            URL schemaURL = null;
            schema = sf.newSchema(schemaURL);
        } catch(Exception e) {
            throw new RuntimeException(e);
        }
    }

    public boolean isReadable(Class<?> arg0, Type arg1, Annotation[] arg2, MediaType arg3) {
        return arg0 == Customer.class;
    }

    public Customer readFrom(Class<Customer> arg0, Type arg1, Annotation[] arg2, MediaType arg3, MultivaluedMap<String, String> arg4, InputStream arg5)
            throws IOException, WebApplicationException {
        try {
            JAXBContext jaxbContext = null;
            ContextResolver<JAXBContext> resolver = providers.getContextResolver(JAXBContext.class, arg3);
            if(null != resolver) {
                jaxbContext = resolver.getContext(arg0);
            }
            if(null == jaxbContext) {
                jaxbContext = JAXBContext.newInstance(arg0);
            }
            Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
            unmarshaller.setSchema(schema);
            return (Customer) unmarshaller.unmarshal(arg5);
        } catch(JAXBException e) {
            throw new RuntimeException(e);
        }
    }

}

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