Description
Transform XML to JSON
License
Open Source License
Parameter
| Parameter | Description |
|---|
| xml | a parameter |
Exception
| Parameter | Description |
|---|
| ParserConfigurationException | an exception |
| SAXException | an exception |
| IOException | an exception |
Declaration
public static String toJson(String xml) throws ParserConfigurationException, SAXException, IOException
Method Source Code
//package com.java2s;
//License from project: Open Source License
import java.io.IOException;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.Base64;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonPrimitive;
public class Main {
private static final String EQ = "\"";
private static final String EMPTY = "";
private static final String ATTR_TEXT = "#text";
static List<Object> ADDED_BY_VALUE = new ArrayList<Object>();
static Map<String, JsonElement> REORGANIZED = new HashMap<String, JsonElement>();
/**// w w w. j av a 2s.c o m
* Transform XML to JSON
*
* @param xml
* @return
* @throws ParserConfigurationException
* @throws SAXException
* @throws IOException
*/
public static String toJson(String xml) throws ParserConfigurationException, SAXException, IOException {
JsonObject rootJson = new JsonObject();
DocumentBuilder dBuilder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document doc = dBuilder.parse(new InputSource(new StringReader(xml)));
if (doc.hasChildNodes()) {
traverseNode(doc, rootJson, null);
}
Gson gson = new GsonBuilder().setPrettyPrinting().disableHtmlEscaping().create();
String json = gson.toJson(rootJson);
return json;
}
private static void traverseNode(Node parentNode, JsonObject parentJson, JsonObject upperJson) {
NodeList childList = parentNode.getChildNodes();
for (int i = 0; i < childList.getLength(); i++) {
JsonObject childJson = new JsonObject();
Node childNode = childList.item(i);
if (childNode.getNodeType() == Node.TEXT_NODE) {
if (childNode.getNodeValue().trim().length() != 0) {
// non empty text node reached, so add to the parent
processTextNode(parentNode, upperJson, childJson, childNode);
}
} else if (childNode.getNodeType() == Node.ELEMENT_NODE) {
if (childNode.hasAttributes()) {
// attributes exist, so go thru them
traverseAttributes(childJson, childNode);
}
if (childNode.hasChildNodes()) {
// child nodes exist, so go into them
traverseNode(childNode, childJson, parentJson);
}
if (childNode.getNodeType() != Node.TEXT_NODE) {
// non text node element
if (ADDED_BY_VALUE.contains(childNode)) {
// already added as a value
if (parentJson.has(childNode.getNodeName())) {
// there is already such an element as expected
JsonElement existing = parentJson.get(childNode.getNodeName());
if (existing instanceof JsonPrimitive) {
// it is a primitive as expected
Iterator attrs = childJson.entrySet().iterator();
if (attrs.hasNext()) {
// there are attributes, so reorganize the element to include the attributes and the
// value as property - #text
reorganizeForAttributes(parentJson, childNode, existing, attrs);
}
} else if (existing instanceof JsonArray) {
// already added and reorganized as an array, so take the last element of this type and
// add the attributes
Iterator attrs = childJson.entrySet().iterator();
if (attrs.hasNext()) {
reorganizeAddAttributes(childNode, attrs);
}
} else if (existing instanceof JsonObject) {
System.err.println("ERROR: found object, but expected primitive or array");
}
} else {
System.err.println("ERROR: expected element, but it does not exist");
}
// remove it from the list
ADDED_BY_VALUE.remove(childNode);
} else {
if (parentJson.has(childNode.getNodeName())) {
// parent already has such an element
JsonElement existing = parentJson.get(childNode.getNodeName());
if (existing instanceof JsonArray) {
// and it is already an array, so just add the child to the array
((JsonArray) existing).add(childJson);
} else if (existing instanceof JsonObject) {
// and it not an array, so reorganize the element
reorganizeElement(parentNode, parentJson, childJson, childNode, existing);
}
} else {
// no such an element yet, so add it to the parent
parentJson.add(childNode.getNodeName(), childJson);
}
}
}
} else if (childNode.getNodeType() == Node.CDATA_SECTION_NODE) {
// processTextNode(parentNode, upperJson, childJson, childNode);
String base64 = Base64.getEncoder().encodeToString(childNode.getNodeValue().getBytes());
parentJson.addProperty(childNode.getNodeName(), base64);
} else {
System.err.println("ERROR: unsupported node type: " + childNode.getNodeType());
}
}
}
private static void processTextNode(Node parentNode, JsonObject upperJson, JsonObject childJson,
Node childNode) {
if (upperJson.has(parentNode.getNodeName())) {
// upper already has such an element
JsonElement existing = upperJson.get(parentNode.getNodeName());
if (existing instanceof JsonArray) {
// adding to the already reorganized array
((JsonArray) existing).add(new JsonPrimitive(childNode.getNodeValue()));
REORGANIZED.put(parentNode.hashCode() + EMPTY, childJson);
} else if (existing instanceof JsonObject) {
// found it as an object, so reorganize it
reorganizeObjectToArray(parentNode, upperJson, childJson, childNode, existing);
} else {
// found as a primitive, so reorganize it
reorganizePrimitiveToArray(parentNode, upperJson, childJson, childNode, existing);
}
} else {
// no such a node exists yet, so add it as a property to the upper element
upperJson.addProperty(parentNode.getNodeName(), childNode.getNodeValue());
}
// add the parent node to the added as a value list
ADDED_BY_VALUE.add(parentNode);
}
private static void traverseAttributes(JsonObject childJson, Node childNode) {
NamedNodeMap attrNodeMap = childNode.getAttributes();
for (int j = 0; j < attrNodeMap.getLength(); j++) {
Node attrNode = attrNodeMap.item(j);
childJson.addProperty("-" + attrNode.getNodeName(), attrNode.getNodeValue());
}
}
private static void reorganizeForAttributes(JsonObject parentJson, Node childNode, JsonElement existing,
Iterator attrs) {
parentJson.remove(childNode.getNodeName());
JsonObject objectJson = new JsonObject();
objectJson.addProperty(ATTR_TEXT, ((JsonPrimitive) existing).getAsString());
while (attrs.hasNext()) {
Entry entry = (Entry) attrs.next();
objectJson.addProperty(entry.getKey().toString(), entry.getValue().toString().replace(EQ, EMPTY));
}
parentJson.add(childNode.getNodeName(), objectJson);
}
private static void reorganizeAddAttributes(Node childNode, Iterator attrs) {
JsonElement reorganizedJson = REORGANIZED.get(childNode.hashCode() + EMPTY);
if (reorganizedJson instanceof JsonObject) {
JsonObject objectJson = (JsonObject) reorganizedJson;
while (attrs.hasNext()) {
Entry entry = (Entry) attrs.next();
objectJson.addProperty(entry.getKey().toString(), entry.getValue().toString().replace(EQ, EMPTY));
}
} else {
System.err.println("ERROR: expected object, found element or null");
}
REORGANIZED.remove(childNode.hashCode() + EMPTY);
}
private static void reorganizeElement(Node parentNode, JsonObject parentJson, JsonObject childJson,
Node childNode, JsonElement existing) {
parentJson.remove(childNode.getNodeName());
JsonArray arrayJson = new JsonArray();
arrayJson.add(existing);
arrayJson.add(childJson);
parentJson.add(childNode.getNodeName(), arrayJson);
}
private static void reorganizeObjectToArray(Node parentNode, JsonObject upperJson, JsonObject childJson,
Node childNode, JsonElement existing) {
upperJson.remove(parentNode.getNodeName());
JsonArray arrayJson = new JsonArray();
arrayJson.add(existing);
childJson.addProperty(childNode.getNodeName(), childNode.getNodeValue());
arrayJson.add(childJson);
upperJson.add(parentNode.getNodeName(), arrayJson);
REORGANIZED.put(parentNode.hashCode() + EMPTY, childJson);
}
private static void reorganizePrimitiveToArray(Node parentNode, JsonObject upperJson, JsonObject childJson,
Node childNode, JsonElement existing) {
upperJson.remove(parentNode.getNodeName());
JsonArray arrayJson = new JsonArray();
arrayJson.add(existing);
arrayJson.add(new JsonPrimitive(childNode.getNodeValue()));
upperJson.add(parentNode.getNodeName(), arrayJson);
REORGANIZED.put(parentNode.hashCode() + EMPTY, childJson);
}
}
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- toElement(String xml)
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- tomcatPort(String fileName)
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- toString(Source input)