public PluginValue(String prop,
    boolean singleton) 
{
         
        super(prop);
        _singleton = singleton;
}

 public String getClassName() 
{
        return _name;
}

The plugin class name.

 protected String getInternalString() 
{
        // should never get called
        throw new IllegalStateException();
}

 public String getProperties() 
{
        return _props;
}

The plugin properties.

 public String getString() 
{
        return Configurations.getPlugin(alias(_name), _props);
}

 public Class getValueType() 
{
        return Object.class;
}

 public Object instantiate(Class type,
    Configuration conf,
    boolean fatal) 
{
        Object obj = newInstance(_name, type, conf, fatal);
        Configurations.configureInstance(obj, conf, _props,
            (fatal) ? getProperty() : null);
        if (_singleton)
            set(obj, true);
        return obj;
}

Instantiate the plugin as an instance of the given class.

 public boolean isSingleton() 
{
        return _singleton;
}

Whether this value is a singleton.

 protected  void objectChanged() 
{
        Object obj = get();
        _name = (obj == null) ? unalias(null) : obj.getClass().getName();
        _props = null;
}

 public  void set(Object obj,
    boolean derived) 
{
        if (!_singleton)
            throw new IllegalStateException(_loc.get("not-singleton",
                getProperty()).getMessage());
        super.set(obj, derived);
}

 public  void setClassName(String name) 
{
        assertChangeable();
        String oldName = _name;
        _name = name;
        if (!StringUtils.equals(oldName, name)) {
            if (_singleton)
                set(null, true);
            valueChanged();
        }
}

The plugin class name.

 protected  void setInternalString(String str) 
{
        // should never get called
        throw new IllegalStateException();
}

 public  void setProperties(String props) 
{
        String oldProps = _props;
        _props = props;
        if (!StringUtils.equals(oldProps, props)) {
            if (_singleton)
                set(null, true);
            valueChanged();
        }
}

The plugin properties.

 public  void setString(String str) 
{
    	assertChangeable();
        _name = Configurations.getClassName(str);
        _name = unalias(_name);
        _props = Configurations.getProperties(str);
        if (_singleton)
            set(null, true);
        valueChanged();
}