com.blazebit.persistence.parser.XmlParser Maven / Gradle / Ivy
/*
* Copyright 2014 - 2020 Blazebit.
*
* 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.blazebit.persistence.parser;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* This is a specialized parser for the XML structure that will be produced by the XML functions in Blaze-Persistence.
* The parser can only parse valid XML that conforms to that structure. Other XML may run into problems.
*
* @author Christian Beikov
* @since 1.5.0
*/
public final class XmlParser {
private XmlParser() {
}
public static List parse(CharSequence xml, String... fields) {
List list = new ArrayList<>();
StringBuilder sb = new StringBuilder();
if (xml != null && xml.length() != 0) {
Map fieldMap = new HashMap<>(fields.length);
for (int i = 0; i < fields.length; i++) {
fieldMap.put(fields[i], i);
}
for (int i = 0; i < xml.length(); i++) {
Object[] object = new Object[fields.length];
boolean key = true;
boolean escape = false;
int fieldIndex = -1;
i = CharSequenceUtils.indexOf(xml, "", i) + 3;
LOOP: for (; i < xml.length(); i++) {
char c = xml.charAt(i);
switch (c) {
case '<':
int endIndex = CharSequenceUtils.indexOf(xml, '>', i);
if (key) {
if (xml.charAt(i + 1) == '/') {
i = endIndex;
break LOOP;
}
String tag = xml.subSequence(i + 1, endIndex).toString();
fieldIndex = fieldMap.get(tag);
i = endIndex;
key = false;
} else {
String tag = xml.subSequence(i + 2, endIndex).toString();
if (xml.charAt(i + 1) != '/' || !tag.equals(fields[fieldIndex])) {
throw new IllegalStateException("Unexpected tag at position: " + i);
}
if (escape) {
object[fieldIndex] = sb.toString();
} else {
object[fieldIndex] = new SubSequence(xml, i - sb.length(), i);
}
key = true;
fieldIndex = -1;
i = endIndex;
}
sb.setLength(0);
break;
case '&':
escape = true;
switch (xml.charAt(i + 1)) {
case 'a':
sb.append('&');
i += 4;
break;
case 'l':
sb.append('<');
i += 3;
break;
case 'g':
sb.append('>');
i += 3;
break;
default:
throw new IllegalStateException("Unexpected escape sequence at position: " + i);
}
break;
default:
sb.append(c);
break;
}
}
list.add(object);
}
}
return list;
}
}