package org.osmtools.osmchange;
import java.io.IOException;
import java.io.InputStream;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.zip.GZIPInputStream;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBElement;
import javax.xml.bind.JAXBException;
import javax.xml.bind.UnmarshalException;
import javax.xml.bind.Unmarshaller;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;
import javax.xml.transform.Source;
import javax.xml.transform.stream.StreamSource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.MediaType;
import org.springframework.http.converter.AbstractHttpMessageConverter;
import org.springframework.http.converter.HttpMessageConversionException;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.http.converter.HttpMessageNotWritableException;
import org.springframework.util.Assert;
public class ReadOnlyGzipJaxb2HttpMessageConverter extends AbstractHttpMessageConverter<Object> {
private final ConcurrentMap<Class, JAXBContext> jaxbContexts = new ConcurrentHashMap<Class, JAXBContext>(64);
public ReadOnlyGzipJaxb2HttpMessageConverter() {
super(new MediaType("application", "x-gzip"));
}
@Override
public boolean canRead(Class<?> clazz, MediaType mediaType) {
return (clazz.isAnnotationPresent(XmlRootElement.class) || clazz.isAnnotationPresent(XmlType.class))
&& canRead(mediaType);
}
@Override
public boolean canWrite(Class<?> clazz, MediaType mediaType) {
return false;
}
@Override
protected boolean supports(Class<?> clazz) {
throw new UnsupportedOperationException();
}
protected Object readFromSource(Class<?> clazz, HttpHeaders headers, Source source) throws IOException {
try {
Unmarshaller unmarshaller = createUnmarshaller(clazz);
if (clazz.isAnnotationPresent(XmlRootElement.class)) {
return unmarshaller.unmarshal(source);
}
else {
JAXBElement jaxbElement = unmarshaller.unmarshal(source, clazz);
return jaxbElement.getValue();
}
}
catch (UnmarshalException ex) {
throw new HttpMessageNotReadableException("Could not unmarshal to [" + clazz + "]: " + ex.getMessage(), ex);
}
catch (JAXBException ex) {
throw new HttpMessageConversionException("Could not instantiate JAXBContext: " + ex.getMessage(), ex);
}
}
@Override
protected Object readInternal(Class<? extends Object> clazz, HttpInputMessage inputMessage) throws IOException,
HttpMessageNotReadableException {
InputStream in = new GZIPInputStream(inputMessage.getBody());
return readFromSource(clazz, inputMessage.getHeaders(), new StreamSource(in));
}
@Override
protected void writeInternal(Object t, HttpOutputMessage outputMessage) throws IOException,
HttpMessageNotWritableException {
throw new UnsupportedOperationException();
}
protected final Unmarshaller createUnmarshaller(Class clazz) throws JAXBException {
try {
JAXBContext jaxbContext = getJaxbContext(clazz);
return jaxbContext.createUnmarshaller();
}
catch (JAXBException ex) {
throw new HttpMessageConversionException("Could not create Unmarshaller for class [" + clazz + "]: "
+ ex.getMessage(), ex);
}
}
protected final JAXBContext getJaxbContext(Class clazz) {
Assert.notNull(clazz, "'clazz' must not be null");
JAXBContext jaxbContext = this.jaxbContexts.get(clazz);
if (jaxbContext == null) {
try {
jaxbContext = JAXBContext.newInstance(clazz);
this.jaxbContexts.putIfAbsent(clazz, jaxbContext);
}
catch (JAXBException ex) {
throw new HttpMessageConversionException("Could not instantiate JAXBContext for class [" + clazz
+ "]: " + ex.getMessage(), ex);
}
}
return jaxbContext;
}
}