com.mycila.xmltool.CachedEntityResolver Maven / Gradle / Ivy
/**
* Copyright (C) 2008 Mycila ([email protected])
*
* 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.mycila.xmltool;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.ext.EntityResolver2;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.StringReader;
import java.io.StringWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.LinkedHashMap;
import java.util.Map;
/**
* @author Mathieu Carbou ([email protected])
*/
final class CachedEntityResolver implements EntityResolver, EntityResolver2 {
static final CachedEntityResolver instance = new CachedEntityResolver();
private Map cache = new LinkedHashMap();
private CachedEntityResolver() {
}
public InputSource getExternalSubset(String name, String baseURI) throws SAXException, IOException {
return new InputSource(new StringReader(""));
}
public InputSource resolveEntity(String name, String publicId, String baseURI, String systemId) throws SAXException, IOException {
return resolveEntity(publicId, systemId);
}
public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
String content = cache.get(systemId);
if (content == null) {
content = read(systemId);
cache.put(systemId, content);
}
return new InputSource(new StringReader(content));
}
private String read(String url) {
try {
URL u = new URL(url);
URLConnection con = u.openConnection();
con.setConnectTimeout(1000);
con.setReadTimeout(1000);
con.setDefaultUseCaches(true);
con.setUseCaches(true);
con.connect();
StringWriter sw = new StringWriter();
BufferedReader br = new BufferedReader(new InputStreamReader(new BufferedInputStream(con.getInputStream()), con.getContentEncoding() != null ? con.getContentEncoding() : "UTF-8"));
char[] buffer = new char[8192];
int c;
while ((c = br.read(buffer)) != -1) {
sw.write(buffer, 0, c);
}
return sw.toString();
} catch (IOException e) {
return "";
}
}
}