/*
* 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.
*/
package org.apache.logging.log4j.util;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.ConcurrentHashMap;
/**
* <em>Consider this class private.</em>
* <p>
* Helps access properties. This utility provides a method to override system properties by specifying properties in a
* properties file.
* </p>
*/
public final class PropertiesUtil {
private static final PropertiesUtil LOG4J_PROPERTIES = new PropertiesUtil("log4j2.component.properties");
private final Properties props;
/**
* Constructs a PropertiesUtil using a given Properties object as its source of defined properties.
*
* @param props the Properties to use by default
*/
public PropertiesUtil(final Properties props) {
this.props = props;
}
/**
* Constructs a PropertiesUtil for a given properties file name on the classpath. The properties specified in this
* file are used by default. If a property is not defined in this file, then the equivalent system property is used.
*
* @param propertiesFileName the location of properties file to load
*/
public PropertiesUtil(final String propertiesFileName) {
final Properties properties = new Properties();
for (final URL url : LoaderUtil.findResources(propertiesFileName)) {
try (final InputStream in = url.openStream()) {
properties.load(in);
} catch (final IOException ioe) {
LowLevelLogUtil.logException("Unable to read " + url.toString(), ioe);
}
}
this.props = properties;
}
/**
* Loads and closes the given property input stream. If an error occurs, log to the status logger.
*
* @param in a property input stream.
* @param source a source object describing the source, like a resource string or a URL.
* @return a new Properties object
*/
static Properties loadClose(final InputStream in, final Object source) {
final Properties props = new Properties();
if (null != in) {
try {
props.load(in);
} catch (final IOException e) {
LowLevelLogUtil.logException("Unable to read " + source, e);
} finally {
try {
in.close();
} catch (final IOException e) {
LowLevelLogUtil.logException("Unable to close " + source, e);
}
}
}
return props;
}
/**
* Returns the PropertiesUtil used by Log4j.
*
* @return the main Log4j PropertiesUtil instance.
*/
public static PropertiesUtil getProperties() {
return LOG4J_PROPERTIES;
}
/**
* Gets the named property as a boolean value. If the property matches the string {@code "true"} (case-insensitive),
* then it is returned as the boolean value {@code true}. Any other non-{@code null} text in the property is
* considered {@code false}.
*
* @param name the name of the property to look up
* @return the boolean value of the property or {@code false} if undefined.
*/
public boolean getBooleanProperty(final String name) {
return getBooleanProperty(name, false);
}
/**
* Gets the named property as a boolean value.
*
* @param name the name of the property to look up
* @param defaultValue the default value to use if the property is undefined
* @return the boolean value of the property or {@code defaultValue} if undefined.
*/
public boolean getBooleanProperty(final String name, final boolean defaultValue) {
final String prop = getStringProperty(name);
return (prop == null) ? defaultValue : "true".equalsIgnoreCase(prop);
}
/**
* Gets the named property as a Charset value.
*
* @param name the name of the property to look up
* @return the Charset value of the property or {@link Charset#defaultCharset()} if undefined.
*/
public Charset getCharsetProperty(final String name) {
return getCharsetProperty(name, Charset.defaultCharset());
}
/**
* Gets the named property as a Charset value.
*
* @param name the name of the property to look up
* @param defaultValue the default value to use if the property is undefined
* @return the Charset value of the property or {@code defaultValue} if undefined.
*/
public Charset getCharsetProperty(final String name, final Charset defaultValue) {
final String prop = getStringProperty(name);
return prop == null ? defaultValue : Charset.forName(prop);
}
/**
* Gets the named property as a double.
*
* @param name the name of the property to look up
* @param defaultValue the default value to use if the property is undefined
* @return the parsed double value of the property or {@code defaultValue} if it was undefined or could not be parsed.
*/
public double getDoubleProperty(final String name, final double defaultValue) {
final String prop = getStringProperty(name);
if (prop != null) {
try {
return Double.parseDouble(prop);
} catch (final Exception ignored) {
return defaultValue;
}
}
return defaultValue;
}
/**
* Gets the named property as an integer.
*
* @param name the name of the property to look up
* @param defaultValue the default value to use if the property is undefined
* @return the parsed integer value of the property or {@code defaultValue} if it was undefined or could not be
* parsed.
*/
public int getIntegerProperty(final String name, final int defaultValue) {
final String prop = getStringProperty(name);
if (prop != null) {
try {
return Integer.parseInt(prop);
} catch (final Exception ignored) {
return defaultValue;
}
}
return defaultValue;
}
/**
* Gets the named property as a long.
*
* @param name the name of the property to look up
* @param defaultValue the default value to use if the property is undefined
* @return the parsed long value of the property or {@code defaultValue} if it was undefined or could not be parsed.
*/
public long getLongProperty(final String name, final long defaultValue) {
final String prop = getStringProperty(name);
if (prop != null) {
try {
return Long.parseLong(prop);
} catch (final Exception ignored) {
return defaultValue;
}
}
return defaultValue;
}
/**
* Gets the named property as a String.
*
* @param name the name of the property to look up
* @return the String value of the property or {@code null} if undefined.
*/
public String getStringProperty(final String name) {
String prop = null;
try {
prop = System.getProperty(name);
} catch (final SecurityException ignored) {
// Ignore
}
return prop == null ? props.getProperty(name) : prop;
}
/**
* Gets the named property as a String.
*
* @param name the name of the property to look up
* @param defaultValue the default value to use if the property is undefined
* @return the String value of the property or {@code defaultValue} if undefined.
*/
public String getStringProperty(final String name, final String defaultValue) {
final String prop = getStringProperty(name);
return (prop == null) ? defaultValue : prop;
}
/**
* Return the system properties or an empty Properties object if an error occurs.
*
* @return The system properties.
*/
public static Properties getSystemProperties() {
try {
return new Properties(System.getProperties());
} catch (final SecurityException ex) {
LowLevelLogUtil.logException("Unable to access system properties.", ex);
// Sandboxed - can't read System Properties
return new Properties();
}
}
/**
* Extracts properties that start with or are equals to the specific prefix and returns them in a new Properties
* object with the prefix removed.
*
* @param properties The Properties to evaluate.
* @param prefix The prefix to extract.
* @return The subset of properties.
*/
public static Properties extractSubset(final Properties properties, final String prefix) {
final Properties subset = new Properties();
if (prefix == null || prefix.length() == 0) {
return subset;
}
final String prefixToMatch = prefix.charAt(prefix.length() - 1) != '.' ? prefix + '.' : prefix;
final List<String> keys = new ArrayList<>();
for (final String key : properties.stringPropertyNames()) {
if (key.startsWith(prefixToMatch)) {
subset.setProperty(key.substring(prefixToMatch.length()), properties.getProperty(key));
keys.add(key);
}
}
for (final String key : keys) {
properties.remove(key);
}
return subset;
}
/**
* Partitions a properties map based on common key prefixes up to the first period.
*
* @param properties properties to partition
* @return the partitioned properties where each key is the common prefix (minus the period) and the values are
* new property maps without the prefix and period in the key
* @since 2.6
*/
public static Map<String, Properties> partitionOnCommonPrefixes(final Properties properties) {
final Map<String, Properties> parts = new ConcurrentHashMap<>();
for (final String key : properties.stringPropertyNames()) {
final String prefix = key.substring(0, key.indexOf('.'));
if (!parts.containsKey(prefix)) {
parts.put(prefix, new Properties());
}
parts.get(prefix).setProperty(key.substring(key.indexOf('.') + 1), properties.getProperty(key));
}
return parts;
}
/**
* Returns true if system properties tell us we are running on Windows.
* @return true if system properties tell us we are running on Windows.
*/
public boolean isOsWindows() {
return getStringProperty("os.name").startsWith("Windows");
}
}