dnet-hadoop/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/plugin/utils/JsonUtils.java

145 lines
3.7 KiB
Java

package eu.dnetlib.dhp.collection.plugin.utils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.json.JSONArray;
import org.json.JSONObject;
public class JsonUtils {
public static final String XML_WRAP_TAG = "recordWrap";
private static final String XML_HEADER = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>";
private static final String INVALID_XMLTAG_CHARS = "!\"#$%&'()*+,/;<=>?@[\\]^`{|}~,";
private static final Log log = LogFactory.getLog(JsonUtils.class);
/**
* cleanup in JSON-KeyName
* check W3C XML syntax: https://www.w3.org/TR/2006/REC-xml11-20060816/#sec-starttags for valid tag names
* and work-around for the JSON to XML converting of org.json.XML-package.
*
* @param input
* @return converted json object
*/
public static JSONObject cleanJsonObject(final JSONObject input) {
if (null == input) {
return null;
}
JSONObject result = new JSONObject();
for (String key : input.keySet()) {
Object value = input.opt(key);
if (value != null) {
result.put(cleanKey(key), cleanValue(value));
}
}
return result;
}
private static Object cleanValue(Object object) {
if (object instanceof JSONObject) {
return cleanJsonObject((JSONObject) object);
} else if (object instanceof JSONArray) {
JSONArray array = (JSONArray) object;
JSONArray res = new JSONArray();
for (int i = array.length() - 1; i >= 0; i--) {
res.put(i, cleanValue(array.opt(i)));
}
return res;
} else if (object instanceof String) {
String value = (String) object;
// XML 1.0 Allowed characters
// Char ::= #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]
return value
.codePoints()
.filter(
cp -> cp == 0x9 || cp == 0xA || cp == 0xD || (cp >= 0x20 && cp <= 0xD7FF)
|| (cp >= 0xE000 && cp <= 0xFFFD)
|| (cp >= 0x10000 && cp <= 0x10FFFF))
.collect(
StringBuilder::new,
StringBuilder::appendCodePoint,
StringBuilder::append)
.toString();
}
return object;
}
private static String cleanKey(String key) {
if (key == null || key.isEmpty()) {
return key;
}
// xml tag cannot begin with "-", ".", or a numeric digit.
switch (key.charAt(0)) {
case '-':
case '.':
key = "_" + key.substring(1);
break;
}
if (Character.isDigit(key.charAt(0))) {
if (key.matches("^[0-9]+$")) {
// add prefix of only numbers in JSON Keynames with 'm_'
key = "m_" + key;
} else {
// add prefix of startNumbers in JSON Keynames with 'n_'
key = "n_" + key;
}
}
StringBuilder res = new StringBuilder(key.length());
for (int i = 0; i < key.length(); i++) {
char c = key.charAt(i);
// sequence of whitespaces are rendered as a single '_'
if (Character.isWhitespace(c)) {
while (i + 1 < key.length() && Character.isWhitespace(key.charAt(i + 1))) {
i++;
}
res.append('_');
}
// remove invalid chars for xml tags with the expception of '=' and '/'
else if (INVALID_XMLTAG_CHARS.indexOf(c) >= 0) {
switch (c) {
case '=':
res.append('-');
break;
case '/':
res.append('_');
break;
default:
break;
}
// nothing
}
// all other chars are kept
else {
res.append(c);
}
}
return res.toString();
}
static public String convertToXML(final String jsonRecord) {
if (log.isTraceEnabled()) {
log.trace("input json: " + jsonRecord);
}
JSONObject jsonObject = cleanJsonObject(new org.json.JSONObject(jsonRecord));
String res = XML_HEADER + org.json.XML.toString(jsonObject, XML_WRAP_TAG); // wrap xml in single root element
if (log.isTraceEnabled()) {
log.trace("outout xml: " + res);
}
return res;
}
}