Read a set of properties from the received input stream, strip off any excess white space that exists in those property values, : Properties « Collections « Java Tutorial

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2. Collections
3. Properties

import java.io.IOException;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.Properties;

/*

   Derby - Class org.apache.derby.iapi.util.PropertyUtil

   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.

 */



public class Main {

  /** 
   * Read a set of properties from the received input stream, strip
   * off any excess white space that exists in those property values,
   * and then add those newly-read properties to the received
   * Properties object; not explicitly removing the whitespace here can
   * lead to problems.
   *
   * This method exists because of the manner in which the jvm reads
   * properties from file--extra spaces are ignored after a _key_, but
   * if they exist at the _end_ of a property decl line (i.e. as part
   * of a _value_), they are preserved, as outlined in the Java API:
   *
   * "Any whitespace after the key is skipped; if the first non-
   * whitespace character after the key is = or :, then it is ignored
   * and any whitespace characters after it are also skipped. All
   * remaining characters on the line become part of the associated
   * element string."
   *
   * @param iStr An input stream from which the new properties are to be
   *  loaded (should already be initialized).
   * @param prop A set of properties to which the properties from
   *  iStr will be added (should already be initialized).
   * properties loaded from 'iStr' (with the extra whitespace (if any)
   *  removed from all values), will be returned via the parameter.
   *
   **/
  public static void loadWithTrimmedValues(InputStream iStr,
    Properties prop) throws IOException {

    if ((iStr == null) || (prop == null)) {
    // shouldn't happen; just ignore this call and return.
      return;
    }

    // Else, load the properties from the received input stream.
    Properties p = new Properties();
    p.load(iStr);

    // Now, trim off any excess whitespace, if any, and then
    // add the properties from file to the received Properties
    // set.
    for (Enumeration propKeys = p.propertyNames();
      propKeys.hasMoreElements();) {
    // get the value, trim off the whitespace, then store it
    // in the received properties object.
      String tmpKey = (String)propKeys.nextElement();
      String tmpValue = p.getProperty(tmpKey);
      tmpValue = tmpValue.trim();
      prop.put(tmpKey, tmpValue);
    }

    return;

  }
}