com.groupbyinc.common.apache.commons.text.lookup.UrlStringLookup 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.io.BufferedInputStream;
import java.io.InputStreamReader;
import java.io.StringWriter;
import java.net.URL;
/**
* Looks up keys from an XML document.
*
* Looks up the value for a given key in the format "Charset:URL".
*
*
* For example: "UTF-8:com/domain/document.properties".
*
*
* @since 1.5
*/
final class UrlStringLookup extends AbstractStringLookup {
/**
* Defines the singleton for this class.
*/
static final UrlStringLookup INSTANCE = new UrlStringLookup();
/**
* No need to build instances for now.
*/
private UrlStringLookup() {
// 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 URL key format [%s]; expected format is DocumentPath:Key.",
key);
}
final String charsetName = keys[0];
final String urlStr = substringAfter(key, SPLIT_CH);
try {
final URL url = new URL(urlStr);
final int size = 8192;
final StringWriter writer = new StringWriter(size);
final char[] buffer = new char[size];
try (InputStreamReader reader = new InputStreamReader(new BufferedInputStream(url.openStream()),
charsetName)) {
int n;
while (-1 != (n = reader.read(buffer))) {
writer.write(buffer, 0, n);
}
}
return writer.toString();
} catch (final Exception e) {
throw IllegalArgumentExceptions.format(e, "Error looking up URL [%s] with Charset [%s].", urlStr,
charsetName);
}
}
}