com.groupbyinc.common.apache.commons.text.lookup.XmlStringLookup Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.commons.text.lookup;
import java.nio.file.Files;
import java.nio.file.Paths;
import javax.xml.xpath.XPathFactory;
import org.xml.sax.InputSource;
/**
* Looks up keys from an XML document.
*
* Looks up the value for a given key in the format "Document:XPath".
*
*
* For example: "com/domain/document.xml:/path/to/node".
*
*
* @since 1.5
*/
final class XmlStringLookup extends AbstractStringLookup {
/**
* Defines the singleton for this class.
*/
static final XmlStringLookup INSTANCE = new XmlStringLookup();
/**
* No need to build instances for now.
*/
private XmlStringLookup() {
// empty
}
/**
* Looks up the value for the key in the format "DocumentPath:XPath".
*
* For example: "com/domain/document.xml:/path/to/node".
*
*
* @param key
* the key to be looked up, may be null
* @return The value associated with the key.
*/
@Override
public String lookup(final String key) {
if (key == null) {
return null;
}
final String[] keys = key.split(SPLIT_STR);
final int keyLen = keys.length;
if (keyLen != 2) {
throw IllegalArgumentExceptions.format("Bad XML key format [%s]; expected format is DocumentPath:XPath.",
key);
}
final String documentPath = keys[0];
final String xpath = substringAfter(key, SPLIT_CH);
try {
return XPathFactory.newInstance().newXPath().evaluate(xpath,
new InputSource(Files.newInputStream(Paths.get(documentPath))));
} catch (final Exception e) {
throw IllegalArgumentExceptions.format(e, "Error looking up XML document [%s] and XPath [%s].",
documentPath, xpath);
}
}
}