| /* |
| * 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. |
| * <p> |
| * Looks up the value for a given key in the format "Charset:URL". |
| * </p> |
| * <p> |
| * For example: "UTF-8:com/domain/document.properties". |
| * </p> |
| * |
| * @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". |
| * <p> |
| * For example: "com/domain/document.xml:/path/to/node". |
| * </p> |
| * |
| * @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); |
| } |
| } |
| |
| } |