Java tutorial
/******************************************************************************* * 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 com.shishu.utility.url; import java.net.MalformedURLException; import java.net.URL; import java.nio.ByteBuffer; import org.apache.avro.util.Utf8; import org.apache.commons.lang.StringUtils; public class TableUtil { public static final ByteBuffer YES_VAL = ByteBuffer.wrap(new byte[] { 'y' }); /** * Reverses a url's domain. This form is better for storing in hbase. Because * scans within the same domain are faster. * <p> * E.g. "http://bar.foo.com:8983/to/index.html?a=b" becomes * "com.foo.bar:8983:http/to/index.html?a=b". * * @param url * url to be reversed * @return Reversed url * @throws MalformedURLException */ public static String reverseUrl(String urlString) throws MalformedURLException { return reverseUrl(new URL(urlString)); } /** * Reverses a url's domain. This form is better for storing in hbase. Because * scans within the same domain are faster. * <p> * E.g. "http://bar.foo.com:8983/to/index.html?a=b" becomes * "com.foo.bar:http:8983/to/index.html?a=b". * * @param url * url to be reversed * @return Reversed url */ public static String reverseUrl(URL url) { String host = url.getHost(); String file = url.getFile(); String protocol = url.getProtocol(); int port = url.getPort(); StringBuilder buf = new StringBuilder(); /* reverse host */ reverseAppendSplits(host, buf); /* add protocol */ buf.append(':'); buf.append(protocol); /* add port if necessary */ if (port != -1) { buf.append(':'); buf.append(port); } /* add path */ if (file.length() > 0 && '/' != file.charAt(0)) { buf.append('/'); } buf.append(file); return buf.toString(); } public static String unreverseUrl(String reversedUrl) { StringBuilder buf = new StringBuilder(reversedUrl.length() + 2); int pathBegin = reversedUrl.indexOf('/'); if (pathBegin == -1) pathBegin = reversedUrl.length(); String sub = reversedUrl.substring(0, pathBegin); String[] splits = StringUtils.split(sub, ':'); // {<reversed host>, <port>, <protocol>} buf.append(splits[1]); // add protocol buf.append("://"); reverseAppendSplits(splits[0], buf); // splits[0] is reversed // host if (splits.length == 3) { // has a port buf.append(':'); buf.append(splits[2]); } buf.append(reversedUrl.substring(pathBegin)); return buf.toString(); } /** * Given a reversed url, returns the reversed host E.g * "com.foo.bar:http:8983/to/index.html?a=b" -> "com.foo.bar" * * @param reversedUrl * Reversed url * @return Reversed host */ public static String getReversedHost(String reversedUrl) { return reversedUrl.substring(0, reversedUrl.indexOf(':')); } private static void reverseAppendSplits(String string, StringBuilder buf) { String[] splits = StringUtils.split(string, '.'); if (splits.length > 0) { for (int i = splits.length - 1; i > 0; i--) { buf.append(splits[i]); buf.append('.'); } buf.append(splits[0]); } else { buf.append(string); } } public static String reverseHost(String hostName) { StringBuilder buf = new StringBuilder(); reverseAppendSplits(hostName, buf); return buf.toString(); } public static String unreverseHost(String reversedHostName) { return reverseHost(reversedHostName); // Reversible } /** * Convert given Utf8 instance to String * * @param utf8 * Utf8 object * @return string-ifed Utf8 object or null if Utf8 instance is null */ public static String toString(CharSequence cs) { return (cs == null ? null : cs.toString()); } /** * Convert given Utf8 instance to String * * @param utf8 * Utf8 object * @return string-ifed Utf8 object or null if Utf8 instance is null */ public static String toString(Utf8 utf8) { return (utf8 == null ? null : utf8.toString()); } }