AttributeEvalParser.java 文件源码

/**
 * @see #instance(Attribute, String, Map)
 * @param attribute
 * @param scriptText
 * @param constVars
 */
private AttributeEvalParser(
        Attribute<T> attribute, 
        String scriptText, 
        Map<String, Comparable<?>> constVars) {
    this.attribute = attribute;
    this.type = (Class<T>) attribute.getType();
    this.scriptText = scriptText;

    manager = new ScriptEngineManager();
    engine = manager.getEngineByName("js"); // javascript

    // compile to make script run faster on each execution
    try {
        script = ((Compilable) engine).compile(scriptText);
    } catch (ScriptException e) {
        e.printStackTrace();
    }

    // bindings for vars
    bindings = engine.createBindings();

    // add vars from constants
    bindings.putAll(constVars);
}