001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 * 017 */ 018 019 package org.apache.commons.exec.environment; 020 021 import java.io.IOException; 022 import java.util.Iterator; 023 import java.util.Map; 024 025 import org.apache.commons.exec.OS; 026 027 /** 028 * Wrapper for environment variables. 029 */ 030 public class EnvironmentUtils 031 { 032 033 private static final DefaultProcessingEnvironment PROCESSING_ENVIRONMENT_IMPLEMENTATION; 034 035 static { 036 if (OS.isFamilyOpenVms()) { 037 PROCESSING_ENVIRONMENT_IMPLEMENTATION = new OpenVmsProcessingEnvironment(); 038 } else { 039 PROCESSING_ENVIRONMENT_IMPLEMENTATION = new DefaultProcessingEnvironment(); 040 } 041 } 042 043 /** 044 * Disable constructor. 045 */ 046 private EnvironmentUtils() { 047 048 } 049 050 /** 051 * Get the variable list as an array. 052 * 053 * @param environment the environment to use, may be <code>null</code> 054 * @return array of key=value assignment strings or <code>null</code> if and only if 055 * the input map was <code>null</code> 056 */ 057 public static String[] toStrings(Map environment) { 058 if (environment == null) { 059 return null; 060 } 061 String[] result = new String[environment.size()]; 062 int i = 0; 063 for (Iterator iter = environment.entrySet().iterator(); iter.hasNext();) { 064 Map.Entry entry = (Map.Entry) iter.next(); 065 066 result[i] = entry.getKey().toString() + "=" + entry.getValue().toString(); 067 i++; 068 } 069 return result; 070 } 071 072 /** 073 * Find the list of environment variables for this process. The returned map preserves 074 * the casing of a variable's name on all platforms but obeys the casing rules of the 075 * current platform during lookup, e.g. key names will be case-insensitive on Windows 076 * platforms. 077 * 078 * @return a map containing the environment variables, may be empty but never <code>null</code> 079 * @throws IOException the operation failed 080 */ 081 public static Map getProcEnvironment() throws IOException { 082 return PROCESSING_ENVIRONMENT_IMPLEMENTATION.getProcEnvironment(); 083 } 084 085 /** 086 * Add a key/value pair to the given environment. 087 * If the key matches an existing key, the previous setting is replaced. 088 * 089 * @param environment the current environment 090 * @param keyAndValue the key/value pair 091 */ 092 public static void addVariableToEnvironment(Map environment, String keyAndValue) { 093 String[] parsedVariable = parseEnvironmentVariable(keyAndValue); 094 environment.put(parsedVariable[0], parsedVariable[1]); 095 } 096 097 /** 098 * Split a key/value pair into a String[]. It is assumed 099 * that the ky/value pair contains a '=' character. 100 * 101 * @param keyAndValue the key/value pair 102 * @return a String[] containing the key and value 103 */ 104 private static String[] parseEnvironmentVariable(final String keyAndValue) { 105 int index = keyAndValue.indexOf('='); 106 if (index == -1) { 107 throw new IllegalArgumentException( 108 "Environment variable for this platform " 109 + "must contain an equals sign ('=')"); 110 } 111 112 String[] result = new String[2]; 113 result[0] = keyAndValue.substring(0, index); 114 result[1] = keyAndValue.substring(index + 1); 115 116 return result; 117 } 118 119 }