ro.isdc.wro.util.RegexpProperties Maven / Gradle / Ivy
package ro.isdc.wro.util;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.Properties;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.Validate;
/**
* Used to overcome the limitation of {@link Properties} class when dealing with regular expressions read from
* properties file. The main benefit of using {@link RegexpProperties} over simple {@link Properties} is that the regexp
* doesn't have to be escaped.
*
* @author Alex Objelean
* @since 1.4.7
* @created 11 Jun 2012
*/
public class RegexpProperties {
private final Properties properties;
private static final String REGEX_KEY_VALUE = "(?m)\\s*(.*?)\\s*=\\s*(.*)\\s*$";
private static final String REGEX_COMMENTS = "#.*";
private static final Pattern PATTERN_KEY_VALUE = Pattern.compile(REGEX_KEY_VALUE);
public RegexpProperties() {
this.properties = new Properties();
}
/**
* Load the properties from the stream. The implementation will handle comments properly by removing them before
* properties are loaded.
*
* @param inputStream
* @return {@link Properties} containing properties parsed from the stream.
* @throws IOException
*/
public Properties load(final InputStream inputStream) throws IOException {
Validate.notNull(inputStream);
final String rawContent = IOUtils.toString(inputStream, StandardCharsets.UTF_8);
parseProperties(rawContent.replaceAll(REGEX_COMMENTS, ""));
return this.properties;
}
/**
* parse the properties from the provided string containing a raw properties
*/
private void parseProperties(final String propertiesAsString) {
//should work also \r?\n
final String[] propertyEntries = propertiesAsString.split("\\r?\\n");
for (final String entry : propertyEntries) {
readPropertyEntry(entry);
}
}
private void readPropertyEntry(final String entry) {
Matcher matcher = PATTERN_KEY_VALUE.matcher(entry);
while(matcher.find()) {
final String key = matcher.group(1);
final String value = matcher.group(2);
this.properties.put(key, value);
}
}
}