/*
* Copyright 2006-2007 the original author or authors.
*
* Licensed 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 org.springframework.batch.support;
import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
import java.util.Arrays;
import java.util.List;
import java.util.Properties;
import org.springframework.util.DefaultPropertiesPersister;
import org.springframework.util.PropertiesPersister;
import org.springframework.util.StringUtils;
/**
* Utility to convert a Properties object to a String and back. Ideally this
* utility should have been used to convert to string in order to convert that
* string back to a Properties Object. Attempting to convert a string obtained
* by calling Properties.toString() will return an invalid Properties object.
* The format of Properties is that used by {@link PropertiesPersister} from the
* Spring Core, so a String in the correct format for a Spring property editor
* is fine (key=value pairs separated by new lines).
*
* @author Lucas Ward
* @author Dave Syer
*
* @see PropertiesPersister
*/
public final class PropertiesConverter {
private static final PropertiesPersister propertiesPersister = new DefaultPropertiesPersister();
private static final String LINE_SEPARATOR = System.getProperty("line.separator");
// prevents the class from being instantiated
private PropertiesConverter() {
}
/**
* Parse a String to a Properties object. If string is null, an empty
* Properties object will be returned. The input String is a set of
* name=value pairs, delimited by either newline or comma (for brevity). If
* the input String contains a newline it is assumed that the separator is
* newline, otherwise comma.
*
* @param stringToParse String to parse.
* @return Properties parsed from each string.
* @see PropertiesPersister
*/
public static Properties stringToProperties(String stringToParse) {
if (stringToParse == null) {
return new Properties();
}
if (!contains(stringToParse, "\n")) {
stringToParse = StringUtils.arrayToDelimitedString(
StringUtils.commaDelimitedListToStringArray(stringToParse), "\n");
}
StringReader stringReader = new StringReader(stringToParse);
Properties properties = new Properties();
try {
propertiesPersister.load(properties, stringReader);
// Exception is only thrown by StringReader after it is closed,
// so never in this case.
}
catch (IOException ex) {
throw new IllegalStateException("Error while trying to parse String to java.util.Properties,"
+ " given String: " + properties);
}
return properties;
}
/**
* Convert Properties object to String. This is only necessary for
* compatibility with converting the String back to a properties object. If
* an empty properties object is passed in, a blank string is returned,
* otherwise it's string representation is returned.
*
* @param propertiesToParse
* @return String representation of properties object
*/
public static String propertiesToString(Properties propertiesToParse) {
// If properties is empty, return a blank string.
if (propertiesToParse == null || propertiesToParse.size() == 0) {
return "";
}
StringWriter stringWriter = new StringWriter();
try {
propertiesPersister.store(propertiesToParse, stringWriter, null);
}
catch (IOException ex) {
// Exception is never thrown by StringWriter
throw new IllegalStateException("Error while trying to convert properties to string");
}
// If the value is short enough (and doesn't contain commas), convert to
// comma-separated...
String value = stringWriter.toString();
if (value.length() < 160) {
List<String> list = Arrays.asList(StringUtils.delimitedListToStringArray(value, LINE_SEPARATOR,
LINE_SEPARATOR));
String shortValue = StringUtils.collectionToCommaDelimitedString(list.subList(1, list.size()));
int count = StringUtils.countOccurrencesOf(shortValue, ",");
if (count == list.size() - 2) {
value = shortValue;
}
if (value.endsWith(",")) {
value = value.substring(0, value.length() - 1);
}
}
return value;
}
private static boolean contains(String str, String searchStr) {
return str.indexOf(searchStr) != -1;
}
}