/*
* ====================================================================
* 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.conn.util;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
/**
* Parses the list from <a href="http://publicsuffix.org/">publicsuffix.org</a>
* and configures a PublicSuffixFilter.
*
* @since 4.4
*/
public final class PublicSuffixListParser {
private static final int MAX_LINE_LEN = 256;
public PublicSuffixListParser() {
}
/**
* Parses the public suffix list format. When creating the reader from the file, make sure to
* use the correct encoding (the original list is in UTF-8).
*
* @param reader the data reader. The caller is responsible for closing the reader.
* @throws java.io.IOException on error while reading from list
*/
public PublicSuffixList parse(final Reader reader) throws IOException {
final List<String> rules = new ArrayList<String>();
final List<String> exceptions = new ArrayList<String>();
final BufferedReader r = new BufferedReader(reader);
final StringBuilder sb = new StringBuilder(256);
boolean more = true;
while (more) {
more = readLine(r, sb);
String line = sb.toString();
if (line.isEmpty()) {
continue;
}
if (line.startsWith("//")) {
continue; //entire lines can also be commented using //
}
if (line.startsWith(".")) {
line = line.substring(1); // A leading dot is optional
}
// An exclamation mark (!) at the start of a rule marks an exception to a previous wildcard rule
final boolean isException = line.startsWith("!");
if (isException) {
line = line.substring(1);
}
if (isException) {
exceptions.add(line);
} else {
rules.add(line);
}
}
return new PublicSuffixList(rules, exceptions);
}
private boolean readLine(final Reader r, final StringBuilder sb) throws IOException {
sb.setLength(0);
int b;
boolean hitWhitespace = false;
while ((b = r.read()) != -1) {
final char c = (char) b;
if (c == '\n') {
break;
}
// Each line is only read up to the first whitespace
if (Character.isWhitespace(c)) {
hitWhitespace = true;
}
if (!hitWhitespace) {
sb.append(c);
}
if (sb.length() > MAX_LINE_LEN) {
return false; // prevent excess memory usage
}
}
return (b != -1);
}
}