com.predic8.membrane.core.interceptor.xml.Xml2JsonInterceptor Maven / Gradle / Ivy
/* Copyright 2021 predic8 GmbH, www.predic8.com
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 com.predic8.membrane.core.interceptor.xml;
import com.predic8.membrane.annot.MCElement;
import com.predic8.membrane.core.exchange.Exchange;
import com.predic8.membrane.core.http.Message;
import com.predic8.membrane.core.http.MimeType;
import com.predic8.membrane.core.interceptor.AbstractInterceptor;
import com.predic8.membrane.core.interceptor.Outcome;
import org.json.XML;
import org.w3c.dom.Document;
import javax.xml.XMLConstants;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.*;
import static com.predic8.membrane.core.interceptor.Outcome.CONTINUE;
import static java.nio.charset.StandardCharsets.UTF_8;
import static javax.xml.transform.OutputKeys.*;
/**
* @description If enabled converts body content from xml to json.
* @explanation Can be used for both request and response. Xml file assumed to be in UTF-8. If input is invalid it returns
* empty json object.
* @topic 4. Interceptors/Features
*/
@MCElement(name="xml2Json")
public class Xml2JsonInterceptor extends AbstractInterceptor {
@Override
public Outcome handleRequest(Exchange exc) throws Exception {
return handleInternal(exc.getRequest());
}
@Override
public Outcome handleResponse(Exchange exc) throws Exception {
return handleInternal(exc.getResponse());
}
private Outcome handleInternal(Message msg) throws Exception {
if(!msg.isXML()){
return CONTINUE;
}
if(msg.getHeader().getContentEncoding() != null){
msg.setBodyContent(xml2json(msg.getBodyAsStreamDecoded(), msg.getHeader().getContentEncoding()));
}
else{
msg.setBodyContent(xml2json(loadXMLFromStream(msg.getBodyAsStreamDecoded())));
}
msg.getHeader().setContentType(MimeType.APPLICATION_JSON_UTF8);
return CONTINUE;
}
private byte[] xml2json(InputStream body, String encoding) throws UnsupportedEncodingException {
return XML.toJSONObject(new InputStreamReader(body, encoding)).toString().getBytes(UTF_8);
}
private byte[] xml2json(String xml) {
return XML.toJSONObject(xml).toString().getBytes(UTF_8);
}
public static String loadXMLFromStream(InputStream stream) throws Exception
{
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
return documentToString(factory.newDocumentBuilder().parse(stream));
}
public static String documentToString(Document doc) {
try {
StringWriter sw = new StringWriter();
TransformerFactory tf = TransformerFactory.newInstance();
tf.setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, "");
tf.setAttribute(XMLConstants.ACCESS_EXTERNAL_STYLESHEET, "");
Transformer transformer = tf.newTransformer();
transformer.setOutputProperty(OMIT_XML_DECLARATION, "no");
transformer.setOutputProperty(METHOD, "xml");
transformer.setOutputProperty(INDENT, "no");
transformer.setOutputProperty(ENCODING, "UTF-8");
transformer.transform(new DOMSource(doc), new StreamResult(sw));
return sw.toString();
} catch (Exception ex) {
throw new RuntimeException("Error converting to String", ex);
}
}
@Override
public String getDisplayName() {
return "XML2JSON";
}
}