com.yahoo.config.LeafNode Maven / Gradle / Ivy
// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.config;
/**
* Superclass for all leaf nodes in a {@link ConfigInstance}.
*
* Subclasses represent leaf nodes with different types. These
* implementations should implement method value() with return-value
* corresponding to the actual type.
*
*/
public abstract class LeafNode extends Node implements Cloneable {
protected boolean initialized;
protected T value;
/**
* Creates a new, uninitialized LeafNode
*/
protected LeafNode() {
initialized = false;
}
/**
* Creates a new LeafNode.
*
* @param initialized true if this node is initialized.
*/
protected LeafNode(boolean initialized) {
this.initialized = initialized;
}
public T value() {
return value;
}
/**
* Subclasses must implement this, in compliance with the rules given in the return tag.
*
* @return the String representation of the node value, or the string "(null)" if the value is null.
*/
public abstract String toString();
/**
* Subclasses must implement this, in compliance with the rules given in the return tag.
*
* @return the String representation of the node value, or the 'null' object if the node value is null.
*/
public abstract String getValue();
/**
* Sets the value based on a string representation. Returns false if the value could
* not be set from the given string.
* TODO: return void (see doSetValue)
*
* @param value the value to set
* @return true on success, false otherwise
* @throws IllegalArgumentException when value is null
*/
protected final boolean setValue(String value) {
if (value == null)
throw new IllegalArgumentException("Null value is not allowed");
return doSetValue(value);
}
// TODO: should throw exception instead of return false.
protected abstract boolean doSetValue(String value);
/**
* This method is meant for internal use in the configuration
* system. Overrides Object.clone().
*
* @return a new instance similar to this object.
*/
@Override
protected LeafNode clone() {
try {
return (LeafNode) super.clone();
} catch (CloneNotSupportedException e) {
throw new ConfigurationRuntimeException(e);
}
}
@Override
public boolean equals(Object o) {
if (! (o instanceof LeafNode other)) return false;
return value == null ? other.value == null : value().equals(other.value);
}
@Override
public int hashCode() {
return (value == null) ? 0 : value.hashCode();
}
void serialize(String name, Serializer serializer) {
serializer.serialize(name, getValue());
}
void serialize(Serializer serializer) {
serializer.serialize(getValue());
}
}