package org.opendaylight.yangtools.yang.data.impl.codec.xml;
+import com.google.common.annotations.Beta;
+import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
-
import java.net.URI;
+import java.util.Map;
import java.util.Map.Entry;
-
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
-
import org.opendaylight.yangtools.yang.common.QName;
import org.opendaylight.yangtools.yang.data.api.AttributesContainer;
import org.opendaylight.yangtools.yang.data.api.CompositeNode;
-import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
import org.opendaylight.yangtools.yang.data.api.Node;
import org.opendaylight.yangtools.yang.data.api.SimpleNode;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
import org.opendaylight.yangtools.yang.data.impl.codec.TypeDefinitionAwareCodec;
import org.opendaylight.yangtools.yang.data.impl.schema.SchemaUtils;
import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
+/**
+ * Utility class for bridging JAXP Stream and YANG Data APIs. Note that the definition of this class
+ * by no means final and subject to change as more functionality is centralized here.
+ */
+@Beta
public class XmlStreamUtils {
private static final Logger LOG = LoggerFactory.getLogger(XmlStreamUtils.class);
+ private final XmlCodecProvider codecProvider;
- public static void writeDataDocument(final XMLStreamWriter writer, final CompositeNode data, final SchemaNode schema, final XmlCodecProvider codecProvider) throws XMLStreamException {
- // final Boolean repairing = (Boolean) writer.getProperty(XMLOutputFactory.IS_REPAIRING_NAMESPACES);
- // Preconditions.checkArgument(repairing == true, "XML Stream Writer has to be repairing namespaces");
+ protected XmlStreamUtils(final XmlCodecProvider codecProvider) {
+ this.codecProvider = Preconditions.checkNotNull(codecProvider);
+ }
- writer.writeStartDocument();
- writeData(writer, data, schema, codecProvider);
- writer.writeEndDocument();
- writer.flush();
+ /**
+ * Create a new instance encapsulating a particular codec provider.
+ *
+ * @param codecProvider XML codec provider
+ * @return A new instance
+ */
+ public static XmlStreamUtils create(final XmlCodecProvider codecProvider) {
+ return new XmlStreamUtils(codecProvider);
}
- public static void writeDataDocument(final XMLStreamWriter writer, final CompositeNode data, final XmlCodecProvider codecProvider) throws XMLStreamException {
- writeDataDocument(writer, data, null, codecProvider);
+ /**
+ * Check if a particular data element can be emitted as an empty element, bypassing value encoding. This
+ * functionality is optional, as valid XML stream is produced even if start/end element is produced unconditionally.
+ *
+ * @param data Data node
+ * @return True if the data node will result in empty element body.
+ */
+ public static boolean isEmptyElement(final Node<?> data) {
+ if (data == null) {
+ return true;
+ }
+
+ if (data instanceof CompositeNode) {
+ return ((CompositeNode) data).getValue().isEmpty();
+ }
+ if (data instanceof SimpleNode) {
+ return data.getValue() == null;
+ }
+
+ // Safe default
+ return false;
}
- public static void write(final XMLStreamWriter writer, final InstanceIdentifier id) throws XMLStreamException {
+ /**
+ * Write an InstanceIdentifier into the output stream. Calling corresponding {@link XMLStreamWriter#writeStartElement(String)}
+ * and {@link XMLStreamWriter#writeEndElement()} is the responsibility of the caller.
+ *
+ * @param writer XML Stream writer
+ * @param id InstanceIdentifier
+ * @throws XMLStreamException
+ */
+ public static void write(final @Nonnull XMLStreamWriter writer, final @Nonnull YangInstanceIdentifier id) throws XMLStreamException {
Preconditions.checkNotNull(writer, "Writer may not be null");
Preconditions.checkNotNull(id, "Variable should contain instance of instance identifier and can't be null");
final String str = XmlUtils.encodeIdentifier(prefixes, id);
for (Entry<URI, String> e: prefixes.getPrefixes()) {
- writer.writeNamespace(e.getValue(), e.getKey().toString());
+ final String ns = e.getKey().toString();
+ final String p = e.getValue();
+
+ writer.writeNamespace(p, ns);
}
writer.writeCharacters(str);
}
- public static void writeData(final XMLStreamWriter writer, final Node<?> data, final SchemaNode schema, final XmlCodecProvider codecProvider) throws XMLStreamException {
+ /**
+ * Write a full XML document corresponding to a CompositeNode into an XML stream writer.
+ *
+ * @param writer XML Stream writer
+ * @param data data node
+ * @param schema corresponding schema node, may be null
+ * @throws XMLStreamException if an encoding problem occurs
+ */
+ public void writeDocument(final @Nonnull XMLStreamWriter writer, final @Nonnull CompositeNode data, final @Nullable SchemaNode schema) throws XMLStreamException {
+ // final Boolean repairing = (Boolean) writer.getProperty(XMLOutputFactory.IS_REPAIRING_NAMESPACES);
+ // Preconditions.checkArgument(repairing == true, "XML Stream Writer has to be repairing namespaces");
+
+ writer.writeStartDocument();
+ writeElement(writer, data, schema);
+ writer.writeEndDocument();
+ writer.flush();
+ }
+
+ /**
+ * Short-hand for {@link #writeDataDocument(XMLStreamWriter, CompositeNode, SchemaNode, XmlCodecProvider)} with
+ * null SchemaNode.
+ *
+ * @param writer XML Stream writer
+ * @param data data node
+ * @param schema corresponding schema node, may be null
+ * @throws XMLStreamException if an encoding problem occurs
+ */
+ public void writeDocument(final XMLStreamWriter writer, final CompositeNode data) throws XMLStreamException {
+ writeDocument(writer, data, null);
+ }
+
+ /**
+ * Write an element into a XML stream writer. This includes the element start/end tags and
+ * the value of the element.
+ *
+ * @param writer XML Stream writer
+ * @param data data node
+ * @param schema Schema node
+ * @throws XMLStreamException if an encoding problem occurs
+ */
+ public void writeElement(final XMLStreamWriter writer, final @Nonnull Node<?> data, final SchemaNode schema) throws XMLStreamException {
final QName qname = data.getNodeType();
final String pfx = qname.getPrefix() != null ? qname.getPrefix() : "";
- final String ns;
- if (qname.getNamespace() != null) {
- ns = qname.getNamespace().toString();
- } else {
- ns = "";
+ final String ns = qname.getNamespace() != null ? qname.getNamespace().toString() : "";
+
+ if (isEmptyElement(data)) {
+ if (hasAttributes(data)) {
+ writer.writeStartElement(pfx, qname.getLocalName(), ns);
+ final RandomPrefix randomPrefix = new RandomPrefix();
+ writeAttributes(writer, (AttributesContainer) data, randomPrefix);
+ writer.writeEndElement();
+ } else {
+ writer.writeEmptyElement(pfx, qname.getLocalName(), ns);
+ }
+ return;
}
writer.writeStartElement(pfx, qname.getLocalName(), ns);
- if (data instanceof AttributesContainer && ((AttributesContainer) data).getAttributes() != null) {
- for (Entry<QName, String> attribute : ((AttributesContainer) data).getAttributes().entrySet()) {
- writer.writeAttribute(attribute.getKey().getNamespace().toString(), attribute.getKey().getLocalName(), attribute.getValue());
- }
+ writeValue(writer, data, schema);
+ writer.writeEndElement();
+ }
+
+ /**
+ * Write a value into a XML stream writer. This method assumes the start and end of element is
+ * emitted by the caller.
+ *
+ * @param writer XML Stream writer
+ * @param data data node
+ * @param schema Schema node
+ * @throws XMLStreamException if an encoding problem occurs
+ */
+ public void writeValue(final XMLStreamWriter writer, final @Nonnull Node<?> data, final SchemaNode schema) throws XMLStreamException {
+ if (hasAttributes(data)) {
+ RandomPrefix randomPrefix = new RandomPrefix();
+ writeAttributes(writer, (AttributesContainer) data, randomPrefix);
}
if (data instanceof SimpleNode<?>) {
// Simple node
if (schema instanceof LeafListSchemaNode) {
- writeValue(writer, ((LeafListSchemaNode) schema).getType(), codecProvider, data.getValue());
+ writeValue(writer, ((LeafListSchemaNode) schema).getType(), data.getValue());
} else if (schema instanceof LeafSchemaNode) {
- writeValue(writer, ((LeafSchemaNode) schema).getType(), codecProvider, data.getValue());
+ writeValue(writer, ((LeafSchemaNode) schema).getType(), data.getValue());
} else {
Object value = data.getValue();
if (value != null) {
}
}
- writeData(writer, child, childSchema, codecProvider);
+ writeElement(writer, child, childSchema);
}
}
+ }
- writer.writeEndElement();
+ private static void writeAttributes(final XMLStreamWriter writer, final AttributesContainer data, final RandomPrefix randomPrefix) throws XMLStreamException {
+ for (Entry<QName, String> attribute : data.getAttributes().entrySet()) {
+ writeAttribute(writer, attribute, randomPrefix);
+ }
+ }
+
+ private static boolean hasAttributes(final Node<?> data) {
+ if (data instanceof AttributesContainer) {
+ final Map<QName, String> c = ((AttributesContainer) data).getAttributes();
+ return c != null && !c.isEmpty();
+ } else {
+ return false;
+ }
+ }
+
+ @VisibleForTesting
+ static void writeAttribute(final XMLStreamWriter writer, final Entry<QName, String> attribute, final RandomPrefix randomPrefix)
+ throws XMLStreamException {
+ final QName key = attribute.getKey();
+ final String prefix = randomPrefix.encodePrefix(key.getNamespace());
+ writer.writeAttribute("xmlns:" + prefix, key.getNamespace().toString());
+ writer.writeAttribute(prefix, key.getNamespace().toString(), key.getLocalName(), attribute.getValue());
}
- public static void writeValue(final XMLStreamWriter writer, final TypeDefinition<?> type, final XmlCodecProvider codecProvider, final Object nodeValue) throws XMLStreamException {
- TypeDefinition<?> baseType = XmlUtils.resolveBaseTypeFrom(type);
+ /**
+ * Write a value into a XML stream writer. This method assumes the start and end of element is
+ * emitted by the caller.
+ *
+ * @param writer XML Stream writer
+ * @param type data type
+ * @param value data value
+ * @throws XMLStreamException if an encoding problem occurs
+ */
+ public void writeValue(final @Nonnull XMLStreamWriter writer, final @Nonnull TypeDefinition<?> type, final Object value) throws XMLStreamException {
+ if (value == null) {
+ LOG.debug("Value of {}:{} is null, not encoding it", type.getQName().getNamespace(), type.getQName().getLocalName());
+ return;
+ }
+
+ final TypeDefinition<?> baseType = XmlUtils.resolveBaseTypeFrom(type);
if (baseType instanceof IdentityrefTypeDefinition) {
- if (nodeValue instanceof QName) {
- QName value = (QName) nodeValue;
- String prefix = "x";
- if (value.getPrefix() != null && !value.getPrefix().isEmpty()) {
- prefix = value.getPrefix();
+ write(writer, (IdentityrefTypeDefinition) baseType, value);
+ } else if (baseType instanceof InstanceIdentifierTypeDefinition) {
+ write(writer, (InstanceIdentifierTypeDefinition) baseType, value);
+ } else {
+ final TypeDefinitionAwareCodec<Object, ?> codec = codecProvider.codecFor(baseType);
+ String text;
+ if (codec != null) {
+ try {
+ text = codec.serialize(value);
+ } catch (ClassCastException e) {
+ LOG.error("Provided node value {} did not have type {} required by mapping. Using stream instead.", value, baseType, e);
+ text = String.valueOf(value);
}
-
- writer.writeNamespace(prefix, value.getNamespace().toString());
- writer.writeCharacters(prefix + ':' + value.getLocalName());
} else {
- Object value = nodeValue;
- LOG.debug("Value of {}:{} is not instance of QName but is {}", baseType.getQName().getNamespace(),
- baseType.getQName().getLocalName(), value != null ? value.getClass() : "null");
- if (value != null) {
- writer.writeCharacters(String.valueOf(value));
- }
+ LOG.error("Failed to find codec for {}, falling back to using stream", baseType);
+ text = String.valueOf(value);
}
- } else if (baseType instanceof InstanceIdentifierTypeDefinition) {
- if (nodeValue instanceof InstanceIdentifier) {
- write(writer, (InstanceIdentifier)nodeValue);
+ writer.writeCharacters(text);
+ }
+ }
+
+ @SuppressWarnings("deprecation")
+ private static void write(final @Nonnull XMLStreamWriter writer, final @Nonnull IdentityrefTypeDefinition type, final @Nonnull Object value) throws XMLStreamException {
+ if (value instanceof QName) {
+ final QName qname = (QName) value;
+ final String prefix;
+ if (qname.getPrefix() != null && !qname.getPrefix().isEmpty()) {
+ prefix = qname.getPrefix();
} else {
- Object value = nodeValue;
- LOG.debug("Value of {}:{} is not instance of InstanceIdentifier but is {}", baseType.getQName()
- .getNamespace(), //
- baseType.getQName().getLocalName(), value != null ? value.getClass() : "null");
- if (value != null) {
- writer.writeCharacters(String.valueOf(value));
- }
+ prefix = "x";
}
+
+ final String ns = qname.getNamespace().toString();
+ writer.writeNamespace(prefix, ns);
+ writer.writeCharacters(prefix + ':' + qname.getLocalName());
} else {
- if (nodeValue != null) {
- final TypeDefinitionAwareCodec<Object, ?> codec = codecProvider.codecFor(baseType);
- String text;
- if (codec != null) {
- try {
- text = codec.serialize(nodeValue);
- } catch (ClassCastException e) {
- LOG.error("Provided node value {} did not have type {} required by mapping. Using stream instead.", nodeValue, baseType, e);
- text = String.valueOf(nodeValue);
- }
- } else {
- LOG.error("Failed to find codec for {}, falling back to using stream", baseType);
- text = String.valueOf(nodeValue);
- }
- writer.writeCharacters(text);
- }
+ LOG.debug("Value of {}:{} is not a QName but {}", type.getQName().getNamespace(), type.getQName().getLocalName(), value.getClass());
+ writer.writeCharacters(String.valueOf(value));
+ }
+ }
+
+ private static void write(final @Nonnull XMLStreamWriter writer, final @Nonnull InstanceIdentifierTypeDefinition type, final @Nonnull Object value) throws XMLStreamException {
+ if (value instanceof YangInstanceIdentifier) {
+ write(writer, (YangInstanceIdentifier)value);
+ } else {
+ LOG.warn("Value of {}:{} is not an InstanceIdentifier but {}", type.getQName().getNamespace(), type.getQName().getLocalName(), value.getClass());
+ writer.writeCharacters(String.valueOf(value));
}
}
}
Code Review / yangtools.git / blobdiff