import jdk.internal.org.xml.sax.ContentHandler; //导入依赖的package包/类
/**
 * Allow an application to register a content event handler.
 *
 * <p>If the application does not register a content handler, all content
 * events reported by the SAX parser will be silently ignored.</p>
 *
 * <p>Applications may register a new or different handler in the middle of
 * a parse, and the SAX parser must begin using the new handler
 * immediately.</p>
 *
 * @param handler The content handler.
 * @exception java.lang.NullPointerException If the handler argument is
 * null.
 * @see #getContentHandler
 */
public void setContentHandler(ContentHandler handler) {
    if (handler == null) {
        throw new NullPointerException();
    }
    mHandCont = handler;
}
 

import jdk.internal.org.xml.sax.ContentHandler; //导入依赖的package包/类
/**
 * Return the current content handler.
 *
 * @return The current content handler, or null if none has been registered.
 * @see #setContentHandler
 */
public ContentHandler getContentHandler() {
    return (mHandCont != mHand) ? mHandCont : null;
}