com.alibaba.cloud.nacos.parser.NacosXmlPropertySourceLoader Maven / Gradle / Ivy
/*
* Copyright 2013-2023 the original author or authors.
*
* 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
*
* https://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 com.alibaba.cloud.nacos.parser;
import java.io.IOException;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import com.alibaba.cloud.nacos.utils.StringUtils;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.springframework.boot.env.OriginTrackedMapPropertySource;
import org.springframework.boot.env.PropertiesPropertySourceLoader;
import org.springframework.core.Ordered;
import org.springframework.core.env.PropertySource;
import org.springframework.core.io.Resource;
/**
* Parsing for XML requires overwriting the default
* {@link PropertiesPropertySourceLoader}, because it internally rigorously validates
* ({@code DOCTYPE}) THE XML in a way that makes it difficult to customize the
* configuration; at finally, make sure it's in the first place.
*
* @author zkz
*/
public class NacosXmlPropertySourceLoader extends AbstractPropertySourceLoader
implements Ordered {
/**
* Get the order value of this object.
*
* Higher values are interpreted as lower priority. As a consequence, the object with
* the lowest value has the highest priority (somewhat analogous to Servlet
* {@code load-on-startup} values).
*
* Same order values will result in arbitrary sort positions for the affected objects.
* @return the order value
* @see #HIGHEST_PRECEDENCE
* @see #LOWEST_PRECEDENCE
*/
@Override
public int getOrder() {
return Integer.MIN_VALUE;
}
/**
* Returns the file extensions that the loader supports (excluding the '.').
* @return the file extensions
*/
@Override
public String[] getFileExtensions() {
return new String[] { "xml" };
}
/**
* Load the resource into one or more property sources. Implementations may either
* return a list containing a single source, or in the case of a multi-document format
* such as yaml a source for each document in the resource.
* @param name the root name of the property source. If multiple documents are loaded
* an additional suffix should be added to the name for each source loaded.
* @param resource the resource to load
* @return a list property sources
* @throws IOException if the source cannot be loaded
*/
@Override
protected List> doLoad(String name, Resource resource)
throws IOException {
Map nacosDataMap = parseXml2Map(resource);
return Collections.singletonList(
new OriginTrackedMapPropertySource(name, nacosDataMap, true));
}
private Map parseXml2Map(Resource resource) throws IOException {
Map map = new LinkedHashMap<>(32);
try {
DocumentBuilder documentBuilder = DocumentBuilderFactory.newInstance()
.newDocumentBuilder();
Document document = documentBuilder.parse(resource.getInputStream());
if (null == document) {
return null;
}
parseNodeList(document.getChildNodes(), map, "");
}
catch (Exception e) {
throw new IOException("The xml content parse error.", e.getCause());
}
return map;
}
private void parseNodeList(NodeList nodeList, Map map,
String parentKey) {
if (nodeList == null || nodeList.getLength() < 1) {
return;
}
parentKey = parentKey == null ? "" : parentKey;
for (int i = 0; i < nodeList.getLength(); i++) {
Node node = nodeList.item(i);
String value = node.getNodeValue();
value = value == null ? "" : value.trim();
String name = node.getNodeName();
name = name == null ? "" : name.trim();
if (StringUtils.isEmpty(name)) {
continue;
}
String key = StringUtils.isEmpty(parentKey) ? name : parentKey + AbstractPropertySourceLoader.DOT + name;
NamedNodeMap nodeMap = node.getAttributes();
parseNodeAttr(nodeMap, map, key);
if (node.getNodeType() == Node.ELEMENT_NODE && node.hasChildNodes()) {
parseNodeList(node.getChildNodes(), map, key);
continue;
}
if (value.length() < 1) {
continue;
}
map.put(parentKey, value);
}
}
private void parseNodeAttr(NamedNodeMap nodeMap, Map map,
String parentKey) {
if (null == nodeMap || nodeMap.getLength() < 1) {
return;
}
for (int i = 0; i < nodeMap.getLength(); i++) {
Node node = nodeMap.item(i);
if (null == node) {
continue;
}
if (node.getNodeType() == Node.ATTRIBUTE_NODE) {
if (StringUtils.isEmpty(node.getNodeName())) {
continue;
}
if (StringUtils.isEmpty(node.getNodeValue())) {
continue;
}
map.put(String.join(AbstractPropertySourceLoader.DOT, parentKey, node.getNodeName()),
node.getNodeValue());
}
}
}
}