【异常】java.lang.IllegalArgumentException: Cannot locate declared field class org.apache.http.impl.client.HttpClientBuilder.dnsResolver 的解决方案

起因：使用htmlunit爬取外部网页的时候遇到这个异常：java.lang.IllegalArgumentException: Cannot locate declared field class org.apache.http.impl.client.HttpClientBuilder.dnsResolver 

<dependency>
    <groupId>net.sourceforge.htmlunit</groupId>
    <artifactId>htmlunit</artifactId>
    <version>2.19</version>
</dependency>

原文：http://www.cnblogs.com/zhaijing/p/7115991.html