import jdk.internal.org.xml.sax.ErrorHandler; //导入依赖的package包/类
/**
 * Allow an application to register an error event handler.
 *
 * <p>If the application does not register an error handler, all error
 * events reported by the SAX parser will be silently ignored; however,
 * normal processing may not continue. It is highly recommended that all SAX
 * applications implement an error handler to avoid unexpected bugs.</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 error handler.
 * @exception java.lang.NullPointerException If the handler argument is
 * null.
 * @see #getErrorHandler
 */
public void setErrorHandler(ErrorHandler handler) {
    if (handler == null) {
        throw new NullPointerException();
    }
    mHandErr = handler;
}
 

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