| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.iapi.util.PropertyUtil |
| 4 | |
| 5 | Copyright 1998, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.iapi.util; |
| 22 | |
| 23 | import java.util.Properties; |
| 24 | import java.util.Enumeration; |
| 25 | import java.io.InputStream; |
| 26 | import java.io.IOException; |
| 27 | |
| 28 | public class PropertyUtil { |
| 29 | |
| 30 | |
| 31 | ////////////////////////////////////////////////////////////////////////////// |
| 32 | // |
| 33 | // SORTS A PROPERTY LIST AND STRINGIFIES THE SORTED PROPERTIES |
| 34 | // |
| 35 | ///////////////////////////////////////////////////////////////////////////// |
| 36 | |
| 37 | /** |
| 38 | * Sorts a property list and turns the sorted list into a string. |
| 39 | * |
| 40 | * @param list property list to sort |
| 41 | * |
| 42 | * @return a string version of the sorted list |
| 43 | */ |
| 44 | public static String sortProperties( Properties list ) |
| 45 | { |
| 46 | // stringify them with no indentation |
| 47 | return sortProperties(list, null); |
| 48 | } |
| 49 | |
| 50 | /** |
| 51 | * Sorts property list and print out each key=value pair prepended with |
| 52 | * specific indentation. If indent is null, do not prepend with |
| 53 | * indentation. |
| 54 | * |
| 55 | * The output string shows up in two styles, style 1 looks like |
| 56 | * { key1=value1, key2=value2, key3=value3 } |
| 57 | * |
| 58 | * style 2 looks like |
| 59 | * key1=value1 |
| 60 | * key2=value2 |
| 61 | * key3=value3 |
| 62 | * where indent goes between the new line and the keys |
| 63 | * |
| 64 | * To get style 1, pass in a null indent |
| 65 | * To get sytle 2, pass in non-null indent (whatever you want to go before |
| 66 | * the key value) |
| 67 | */ |
| 68 | public static String sortProperties( Properties list, String indent ) |
| 69 | { |
| 70 | int size = list == null ? 0 : list.size(); |
| 71 | int count = 0; |
| 72 | String[] array = new String[size]; |
| 73 | String key; |
| 74 | String value; |
| 75 | StringBuffer buffer; |
| 76 | |
| 77 | // Calculate the number of properties in the property list and |
| 78 | // build an array of all the property names. |
| 79 | // We need to go thru the enumeration because Properties has a |
| 80 | // recursive list of defaults. |
| 81 | if (list != null) |
| 82 | { |
| 83 | for (Enumeration propertyNames = list.propertyNames(); |
| 84 | propertyNames.hasMoreElements(); ) |
| 85 | { |
| 86 | if (count == size) |
| 87 | { |
| 88 | // need to expand the array |
| 89 | size = size*2; |
| 90 | String[] expandedArray = new String[size]; |
| 91 | System.arraycopy(array, 0, expandedArray, 0, count); |
| 92 | array = expandedArray; |
| 93 | } |
| 94 | key = (String) propertyNames.nextElement(); |
| 95 | array[ count++ ] = key; |
| 96 | } |
| 97 | |
| 98 | // now sort the array |
| 99 | java.util.Arrays.sort(array, 0, count); |
| 100 | } |
| 101 | |
| 102 | // now stringify the array |
| 103 | buffer = new StringBuffer(); |
| 104 | if (indent == null) |
| 105 | buffer.append( "{ " ); |
| 106 | |
| 107 | for ( int ictr = 0; ictr < count; ictr++ ) |
| 108 | { |
| 109 | if ( ictr > 0 && indent == null) |
| 110 | buffer.append( ", " ); |
| 111 | |
| 112 | key = array[ ictr ]; |
| 113 | |
| 114 | if (indent != null) |
| 115 | buffer.append( indent ); |
| 116 | |
| 117 | buffer.append( key ); buffer.append( "=" ); |
| 118 | |
| 119 | value = list.getProperty( key, "MISSING_VALUE" ); |
| 120 | buffer.append( value ); |
| 121 | |
| 122 | if (indent != null) |
| 123 | buffer.append( "\n" ); |
| 124 | |
| 125 | } |
| 126 | if (indent == null) |
| 127 | buffer.append( " }" ); |
| 128 | |
| 129 | return buffer.toString(); |
| 130 | } |
| 131 | |
| 132 | /** |
| 133 | * Copy a set of properties from one Property to another. |
| 134 | * <p> |
| 135 | * |
| 136 | * @param src_prop Source set of properties to copy from. |
| 137 | * @param dest_prop Dest Properties to copy into. |
| 138 | * |
| 139 | **/ |
| 140 | public static void copyProperties(Properties src_prop, Properties dest_prop) |
| 141 | { |
| 142 | for (Enumeration propertyNames = src_prop.propertyNames(); |
| 143 | propertyNames.hasMoreElements(); ) |
| 144 | { |
| 145 | Object key = propertyNames.nextElement(); |
| 146 | dest_prop.put(key, src_prop.get(key)); |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | /** |
| 151 | * Read a set of properties from the received input stream, strip |
| 152 | * off any excess white space that exists in those property values, |
| 153 | * and then add those newly-read properties to the received |
| 154 | * Properties object; not explicitly removing the whitespace here can |
| 155 | * lead to problems. |
| 156 | * |
| 157 | * This method exists because of the manner in which the jvm reads |
| 158 | * properties from file--extra spaces are ignored after a _key_, but |
| 159 | * if they exist at the _end_ of a property decl line (i.e. as part |
| 160 | * of a _value_), they are preserved, as outlined in the Java API: |
| 161 | * |
| 162 | * "Any whitespace after the key is skipped; if the first non- |
| 163 | * whitespace character after the key is = or :, then it is ignored |
| 164 | * and any whitespace characters after it are also skipped. All |
| 165 | * remaining characters on the line become part of the associated |
| 166 | * element string." |
| 167 | * |
| 168 | * @param iStr An input stream from which the new properties are to be |
| 169 | * loaded (should already be initialized). |
| 170 | * @param prop A set of properties to which the properties from |
| 171 | * iStr will be added (should already be initialized). |
| 172 | * properties loaded from 'iStr' (with the extra whitespace (if any) |
| 173 | * removed from all values), will be returned via the parameter. |
| 174 | * |
| 175 | **/ |
| 176 | public static void loadWithTrimmedValues(InputStream iStr, |
| 177 | Properties prop) throws IOException { |
| 178 | |
| 179 | if ((iStr == null) || (prop == null)) { |
| 180 | // shouldn't happen; just ignore this call and return. |
| 181 | return; |
| 182 | } |
| 183 | |
| 184 | // Else, load the properties from the received input stream. |
| 185 | Properties p = new Properties(); |
| 186 | p.load(iStr); |
| 187 | |
| 188 | // Now, trim off any excess whitespace, if any, and then |
| 189 | // add the properties from file to the received Properties |
| 190 | // set. |
| 191 | for (Enumeration propKeys = p.propertyNames(); |
| 192 | propKeys.hasMoreElements();) { |
| 193 | // get the value, trim off the whitespace, then store it |
| 194 | // in the received properties object. |
| 195 | String tmpKey = (String)propKeys.nextElement(); |
| 196 | String tmpValue = p.getProperty(tmpKey); |
| 197 | tmpValue = tmpValue.trim(); |
| 198 | prop.put(tmpKey, tmpValue); |
| 199 | } |
| 200 | |
| 201 | return; |
| 202 | |
| 203 | } |
| 204 | } |
| 205 | |