org.apache.logging.log4j.core.config.Property Maven / Gradle / Ivy
/*
* 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.core.config;
import java.util.Objects;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
import org.apache.logging.log4j.core.config.plugins.PluginFactory;
import org.apache.logging.log4j.core.config.plugins.PluginValue;
import org.apache.logging.log4j.core.lookup.StrSubstitutor;
import org.apache.logging.log4j.status.StatusLogger;
import org.apache.logging.log4j.util.Strings;
/**
* Represents a key/value pair in the configuration.
*/
@Plugin(name = "property", category = Node.CATEGORY, printObject = true)
public final class Property {
/**
* @since 2.11.2
*/
public static final Property[] EMPTY_ARRAY = {};
private static final Logger LOGGER = StatusLogger.getLogger();
private final String name;
private final String rawValue;
private final String value;
private final boolean valueNeedsLookup;
private Property(final String name, final String rawValue, final String value) {
this.name = name;
this.rawValue = rawValue;
this.value = value;
this.valueNeedsLookup = value != null && value.contains("${");
}
/**
* Returns the property name.
* @return the property name.
*/
public String getName() {
return name;
}
/**
* Returns the original raw property value without substitution.
* @return the raw value of the property, or empty string if it is not set.
*/
public String getRawValue() {
return Objects.toString(rawValue, Strings.EMPTY);
}
/**
* Returns the property value.
* @return the value of the property.
*/
public String getValue() {
return Objects.toString(value, Strings.EMPTY); // LOG4J2-1313 null would be same as Property not existing
}
/**
* Returns {@code true} if the value contains a substitutable property that requires a lookup to be resolved.
* @return {@code true} if the value contains {@code "${}"}, {@code false} otherwise
*/
public boolean isValueNeedsLookup() {
return valueNeedsLookup;
}
/**
* Evaluate this property with the provided substitutor. If {@link #isValueNeedsLookup()} is {@code false},
* the {@link #getValue() value} is returned, otherwise the {@link #getRawValue() raw value} is evaluated
* with the given substitutor.
*/
public String evaluate(final StrSubstitutor substitutor) {
return valueNeedsLookup
// Unescape the raw value first, handling '$${ctx:foo}' -> '${ctx:foo}'
? substitutor.replace(PropertiesPlugin.unescape(getRawValue()))
: getValue();
}
/**
* Creates a Property.
*
* @param name The key.
* @param value The value.
* @return A Property.
*/
public static Property createProperty(final String name, final String value) {
return createProperty(name, value, value);
}
/**
* Creates a Property.
*
* @param name The key.
* @param rawValue The value without any substitution applied.
* @param value The value.
* @return A Property.
*/
public static Property createProperty(final String name, final String rawValue, final String value) {
if (name == null) {
throw new IllegalArgumentException("Property name cannot be null");
}
return new Property(name, rawValue, value);
}
/**
* Creates a Property.
*
* @param name The key.
* @param rawValue The value without any substitution applied.
* @param configuration configuration used to resolve the property value from the rawValue
* @return A Property.
*/
@PluginFactory
public static Property createProperty(
@PluginAttribute("name") final String name,
@PluginValue(value = "value", substitute = false) final String rawValue,
@PluginConfiguration final Configuration configuration) {
return createProperty(
name,
rawValue,
configuration == null
? rawValue
: configuration.getStrSubstitutor().replace(rawValue));
}
@Override
public String toString() {
return name + '=' + getValue();
}
}