org.hibernate.util.PropertiesHelper Maven / Gradle / Ivy
//$Id: PropertiesHelper.java 12890 2007-08-03 03:58:13Z [email protected] $
package org.hibernate.util;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.util.StringTokenizer;
import java.util.Iterator;
/**
* Collection of helper methods for dealing with {@link java.util.Properties}
* objects.
*
* @author Gavin King
* @author Steve Ebersole
*/
public final class PropertiesHelper {
private static final String PLACEHOLDER_START = "${";
/**
* Disallow instantiation
*/
private PropertiesHelper() {
}
/**
* Get a property value as a string.
*
* @see #extractPropertyValue(String, java.util.Properties)
*
* @param propertyName The name of the property for which to retrieve value
* @param properties The properties object
* @param defaultValue The default property value to use.
* @return The property value; may be null.
*/
public static String getString(String propertyName, Properties properties, String defaultValue) {
String value = extractPropertyValue( propertyName, properties );
return value == null ? defaultValue : value;
}
/**
* Extract a property value by name from the given properties object.
*
* Both null and empty string are viewed as the same, and return null.
*
* @param propertyName The name of the property for which to extract value
* @param properties The properties object
* @return The property value; may be null.
*/
public static String extractPropertyValue(String propertyName, Properties properties) {
String value = properties.getProperty( propertyName );
if ( value == null ) {
return null;
}
value = value.trim();
if ( StringHelper.isEmpty( value ) ) {
return null;
}
return value;
}
/**
* Get a property value as a boolean. Shorthand for calling
* {@link #getBoolean(String, java.util.Properties, boolean)} with false
* as the default value.
*
* @param propertyName The name of the property for which to retrieve value
* @param properties The properties object
* @return The property value.
*/
public static boolean getBoolean(String propertyName, Properties properties) {
return getBoolean( propertyName, properties, false );
}
/**
* Get a property value as a boolean.
*
* First, the string value is extracted, and then {@link Boolean#valueOf(String)} is
* used to determine the correct boolean value.
*
* @see #extractPropertyValue(String, java.util.Properties)
*
* @param propertyName The name of the property for which to retrieve value
* @param properties The properties object
* @param defaultValue The default property value to use.
* @return The property value.
*/
public static boolean getBoolean(String propertyName, Properties properties, boolean defaultValue) {
String value = extractPropertyValue( propertyName, properties );
return value == null ? defaultValue : Boolean.valueOf( value ).booleanValue();
}
/**
* Get a property value as an int.
*
* First, the string value is extracted, and then {@link Integer#parseInt(String)} is
* used to determine the correct int value for any non-null property values.
*
* @see #extractPropertyValue(String, java.util.Properties)
*
* @param propertyName The name of the property for which to retrieve value
* @param properties The properties object
* @param defaultValue The default property value to use.
* @return The property value.
*/
public static int getInt(String propertyName, Properties properties, int defaultValue) {
String value = extractPropertyValue( propertyName, properties );
return value == null ? defaultValue : Integer.parseInt( value );
}
/**
* Get a property value as an Integer.
*
* First, the string value is extracted, and then {@link Integer#valueOf(String)} is
* used to determine the correct boolean value for any non-null property values.
*
* @see #extractPropertyValue(String, java.util.Properties)
*
* @param propertyName The name of the property for which to retrieve value
* @param properties The properties object
* @return The property value; may be null.
*/
public static Integer getInteger(String propertyName, Properties properties) {
String value = extractPropertyValue( propertyName, properties );
return value == null ? null : Integer.valueOf( value );
}
/**
* Constructs a map from a property value.
*
* The exact behavior here is largely dependant upon what is passed in as
* the delimiter.
*
* @see #extractPropertyValue(String, java.util.Properties)
*
* @param propertyName The name of the property for which to retrieve value
* @param delim The string defining tokens used as both entry and key/value delimiters.
* @param properties The properties object
* @return The resulting map; never null, though perhaps empty.
*/
public static Map toMap(String propertyName, String delim, Properties properties) {
Map map = new HashMap();
String value = extractPropertyValue( propertyName, properties );
if ( value != null ) {
StringTokenizer tokens = new StringTokenizer( value, delim );
while ( tokens.hasMoreTokens() ) {
map.put( tokens.nextToken(), tokens.hasMoreElements() ? tokens.nextToken() : "" );
}
}
return map;
}
/**
* Get a property value as a string array.
*
* @see #extractPropertyValue(String, java.util.Properties)
* @see #toStringArray(String, String)
*
* @param propertyName The name of the property for which to retrieve value
* @param delim The delimiter used to separate individual array elements.
* @param properties The properties object
* @return The array; never null, though may be empty.
*/
public static String[] toStringArray(String propertyName, String delim, Properties properties) {
return toStringArray( extractPropertyValue( propertyName, properties ), delim );
}
/**
* Convert a string to an array of strings. The assumption is that
* the individual array elements are delimited in the source stringForm
* param by the delim param.
*
* @param stringForm The string form of the string array.
* @param delim The delimiter used to separate individual array elements.
* @return The array; never null, though may be empty.
*/
public static String[] toStringArray(String stringForm, String delim) {
// todo : move to StringHelper?
if ( stringForm != null ) {
return StringHelper.split( delim, stringForm );
}
else {
return ArrayHelper.EMPTY_STRING_ARRAY;
}
}
/**
* replace a property by a starred version
*
* @param props properties to check
* @param key proeprty to mask
* @return cloned and masked properties
*/
public static Properties maskOut(Properties props, String key) {
Properties clone = ( Properties ) props.clone();
if ( clone.get( key ) != null ) {
clone.setProperty( key, "****" );
}
return clone;
}
/**
* Handles interpolation processing for all entries in a properties object.
*
* @param properties The properties object.
*/
public static void resolvePlaceHolders(Properties properties) {
Iterator itr = properties.entrySet().iterator();
while ( itr.hasNext() ) {
final Map.Entry entry = ( Map.Entry ) itr.next();
final Object value = entry.getValue();
if ( value != null && String.class.isInstance( value ) ) {
final String resolved = resolvePlaceHolder( ( String ) value );
if ( !value.equals( resolved ) ) {
if ( resolved == null ) {
itr.remove();
}
else {
entry.setValue( resolved );
}
}
}
}
}
/**
* Handles interpolation processing for a single property.
*
* @param property The property value to be processed for interpolation.
* @return The (possibly) interpolated property value.
*/
public static String resolvePlaceHolder(String property) {
if ( property.indexOf( PLACEHOLDER_START ) < 0 ) {
return property;
}
StringBuffer buff = new StringBuffer();
char[] chars = property.toCharArray();
for ( int pos = 0; pos < chars.length; pos++ ) {
if ( chars[pos] == '$' ) {
// peek ahead
if ( chars[pos+1] == '{' ) {
// we have a placeholder, spin forward till we find the end
String systemPropertyName = "";
int x = pos + 2;
for ( ; x < chars.length && chars[x] != '}'; x++ ) {
systemPropertyName += chars[x];
// if we reach the end of the string w/o finding the
// matching end, that is an exception
if ( x == chars.length - 1 ) {
throw new IllegalArgumentException( "unmatched placeholder start [" + property + "]" );
}
}
String systemProperty = extractFromSystem( systemPropertyName );
buff.append( systemProperty == null ? "" : systemProperty );
pos = x + 1;
// make sure spinning forward did not put us past the end of the buffer...
if ( pos >= chars.length ) {
break;
}
}
}
buff.append( chars[pos] );
}
String rtn = buff.toString();
return StringHelper.isEmpty( rtn ) ? null : rtn;
}
private static String extractFromSystem(String systemPropertyName) {
try {
return System.getProperty( systemPropertyName );
}
catch( Throwable t ) {
return null;
}
}
}
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