BeanDefinitionParserDelegate.java 文件源码

/**
 * Return a typed String value Object for the given 'idref' element.
 */
public Object parseIdRefElement(Element ele) {
    // A generic reference to any name of any bean.
    String refName = ele.getAttribute(BEAN_REF_ATTRIBUTE);
    if (!StringUtils.hasLength(refName)) {
        // A reference to the id of another bean in the same XML file.
        refName = ele.getAttribute(LOCAL_REF_ATTRIBUTE);
        if (!StringUtils.hasLength(refName)) {
            error("Either 'bean' or 'local' is required for <idref> element", ele);
            return null;
        }
    }
    if (!StringUtils.hasText(refName)) {
        error("<idref> element contains empty target attribute", ele);
        return null;
    }
    RuntimeBeanNameReference ref = new RuntimeBeanNameReference(refName);
    ref.setSource(extractSource(ele));
    return ref;
}