001 /** 002 * Copyright (c) 2010 Yahoo! Inc. All rights reserved. 003 * Licensed under the Apache License, Version 2.0 (the "License"); 004 * you may not use this file except in compliance with the License. 005 * You may obtain a copy of the License at 006 * 007 * http://www.apache.org/licenses/LICENSE-2.0 008 * 009 * Unless required by applicable law or agreed to in writing, software 010 * distributed under the License is distributed on an "AS IS" BASIS, 011 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012 * See the License for the specific language governing permissions and 013 * limitations under the License. See accompanying LICENSE file. 014 */ 015 package org.apache.oozie.util; 016 017 import java.text.SimpleDateFormat; 018 import java.util.TimeZone; 019 import java.util.Date; 020 import java.net.URLEncoder; 021 import java.io.UnsupportedEncodingException; 022 023 /** 024 * Base EL constants and functions. 025 */ 026 public class ELConstantsFunctions { 027 028 /** 029 * KiloByte constant (1024). Defined for EL as 'KB'. 030 */ 031 public static final long KB = 1024; 032 033 /** 034 * MegaByte constant (1024 KB). Defined for EL as 'MB'. 035 */ 036 public static final long MB = KB * 1024; 037 038 /** 039 * GigaByte constant (1024 MB). Defined for EL as 'GB'. 040 */ 041 public static final long GB = MB * 1024; 042 043 /** 044 * TeraByte constant (1024 GB). Defined for EL as 'TB'. 045 */ 046 public static final long TB = GB * 1024; 047 048 /** 049 * PetaByte constant (1024 TB). Defined for EL as 'PB'. 050 */ 051 public static final long PB = TB * 1024; 052 053 public static final int SUBMIT_MINUTES = 1; 054 public static final int SUBMIT_HOURS = 60; 055 public static final int SUBMIT_DAYS = 24 * 60; 056 057 /** 058 * Return the first not <code>null</code> value, or <code>null</code> if both are <code>null</code>. Defined for EL 059 * as 'Object firstNotNull(Object, Object)'. 060 * 061 * @param o1 first value. 062 * @param o2 second value. 063 * @return the first not <code>null</code> value, or or <code>null</code> if both are <code>null</code> 064 */ 065 public static Object firstNotNull(Object o1, Object o2) { 066 return (o1 != null) ? o1 : o2; 067 } 068 069 /** 070 * Return the concatenation of 2 strings. <p/> A string with <code>null</code> value is considered as an empty 071 * string. 072 * 073 * @param s1 first string. 074 * @param s2 second string. 075 * @return the concatenation of <code>s1</code> and <code>s2</code>. 076 */ 077 public static String concat(String s1, String s2) { 078 StringBuilder sb = new StringBuilder(); 079 if (s1 != null) { 080 sb.append(s1); 081 } 082 if (s2 != null) { 083 sb.append(s2); 084 } 085 return sb.toString(); 086 } 087 088 /** 089 * Return the trimmed version of the given string. 090 * 091 * @param input string to be trimmed 092 * @return the trimmed version of the given string or the empty string if the given string was <code>null</code> 093 */ 094 public static String trim(String input) { 095 return (input == null) ? "" : input.trim(); 096 } 097 098 /** 099 * Return the UTC current date and time in W3C format down to second (yyyy-MM-ddTHH:mm:ssZ). i.e.: 100 * 1997-07-16T19:20:30Z 101 * 102 * @return the formatted time string. 103 */ 104 public static String timestamp() { 105 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'"); 106 sdf.setTimeZone(TimeZone.getTimeZone("UTC")); 107 return sdf.format(new Date()); 108 } 109 110 /** 111 * Translates a string into <code>application/x-www-form-urlencoded</code> format using UTF-8 encoding scheme. Bytes 112 * for unsafe characters are also obtained using UTF-8 scheme. 113 * 114 * @param input string to be encoded 115 * @return the encoded <code>String</code> 116 */ 117 public static String urlEncode(String input) { 118 try { 119 return (input == null) ? "" : URLEncoder.encode(input, "UTF-8"); 120 } 121 catch (UnsupportedEncodingException uee) { 122 throw new RuntimeException("It should never happen"); 123 } 124 } 125 126 }