feign.jaxb.JAXBDecoder Maven / Gradle / Ivy
/*
* Copyright © 2012 The Feign Authors ([email protected])
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package feign.jaxb;
import feign.Response;
import feign.Util;
import feign.codec.DecodeException;
import feign.codec.Decoder;
import jakarta.xml.bind.JAXBException;
import java.io.IOException;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.transform.sax.SAXSource;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
/**
* Decodes responses using JAXB with Jakarta Api.
*
* Basic example with with Feign.Builder:
*
*
* JAXBContextFactory jaxbFactory = new JAXBContextFactory.Builder()
* .withMarshallerJAXBEncoding("UTF-8")
* .withMarshallerSchemaLocation("http://apihost http://apihost/schema.xsd")
* .build();
*
* api = Feign.builder()
* .decoder(new JAXBDecoder(jaxbFactory))
* .target(MyApi.class, "http://api");
*
*
* The JAXBContextFactory should be reused across requests as it caches the created JAXB
* contexts.
*/
public class JAXBDecoder implements Decoder {
private final JAXBContextFactory jaxbContextFactory;
private final boolean namespaceAware;
public JAXBDecoder(JAXBContextFactory jaxbContextFactory) {
this.jaxbContextFactory = jaxbContextFactory;
this.namespaceAware = true;
}
private JAXBDecoder(Builder builder) {
this.jaxbContextFactory = builder.jaxbContextFactory;
this.namespaceAware = builder.namespaceAware;
}
@Override
public Object decode(Response response, Type type) throws IOException {
if (response.status() == 404 || response.status() == 204) return Util.emptyValueOf(type);
if (response.body() == null) return null;
while (type instanceof ParameterizedType) {
ParameterizedType ptype = (ParameterizedType) type;
type = ptype.getRawType();
}
if (!(type instanceof Class)) {
throw new UnsupportedOperationException(
"JAXB only supports decoding raw types. Found " + type);
}
try {
SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
/* Explicitly control sax configuration to prevent XXE attacks */
saxParserFactory.setFeature("http://xml.org/sax/features/external-general-entities", false);
saxParserFactory.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
saxParserFactory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", false);
saxParserFactory.setFeature(
"http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
saxParserFactory.setNamespaceAware(namespaceAware);
return jaxbContextFactory
.createUnmarshaller((Class) type)
.unmarshal(
new SAXSource(
saxParserFactory.newSAXParser().getXMLReader(),
new InputSource(response.body().asInputStream())));
} catch (JAXBException | ParserConfigurationException | SAXException e) {
throw new DecodeException(response.status(), e.toString(), response.request(), e);
} finally {
if (response.body() != null) {
response.body().close();
}
}
}
public static class Builder {
private boolean namespaceAware = true;
private JAXBContextFactory jaxbContextFactory;
/** Controls whether the underlying XML parser is namespace aware. Default is true. */
public Builder withNamespaceAware(boolean namespaceAware) {
this.namespaceAware = namespaceAware;
return this;
}
public Builder withJAXBContextFactory(JAXBContextFactory jaxbContextFactory) {
this.jaxbContextFactory = jaxbContextFactory;
return this;
}
public JAXBDecoder build() {
if (jaxbContextFactory == null) {
throw new IllegalStateException("JAXBContextFactory must be non-null");
}
return new JAXBDecoder(this);
}
}
}