src/main/java/org/wltea/analyzer/dic/Monitor.java
public void runUnprivileged() {

		//超时设置
		RequestConfig rc = RequestConfig.custom().setConnectionRequestTimeout(10*1000)
				.setConnectTimeout(10*1000).setSocketTimeout(15*1000).build();

		HttpHead head = new HttpHead(location);
		head.setConfig(rc);

		//设置请求头
		if (last_modified != null) {
			head.setHeader("If-Modified-Since", last_modified);
		}
		if (eTags != null) {
			head.setHeader("If-None-Match", eTags);
		}

		CloseableHttpResponse response = null;
		try {

			response = httpclient.execute(head);

			//返回200 才做操作
			if(response.getStatusLine().getStatusCode()==200){

				if (((response.getLastHeader("Last-Modified")!=null) && !response.getLastHeader("Last-Modified").getValue().equalsIgnoreCase(last_modified))
						||((response.getLastHeader("ETag")!=null) && !response.getLastHeader("ETag").getValue().equalsIgnoreCase(eTags))) {

					// 远程词库有更新,需要重新加载词典，并修改last_modified,eTags
					Dictionary.getSingleton().reLoadMainDict();
					last_modified = response.getLastHeader("Last-Modified")==null?null:response.getLastHeader("Last-Modified").getValue();
					eTags = response.getLastHeader("ETag")==null?null:response.getLastHeader("ETag").getValue();
				}
			}else if (response.getStatusLine().getStatusCode()==304) {
				//没有修改，不做操作
				//noop
			}else{
				logger.info("remote_ext_dict {} return bad code {}" , location , response.getStatusLine().getStatusCode() );
			}

		} catch (Exception e) {
			logger.error("remote_ext_dict {} error!",e , location);
		}finally{
			try {
				if (response != null) {
					response.close();
				}
			} catch (IOException e) {
				logger.error(e.getMessage(), e);
			}
		}
	}
public void runUnprivileged() {

		//超时设置
		RequestConfig rc = RequestConfig.custom().setConnectionRequestTimeout(10*1000)
				.setConnectTimeout(10*1000).setSocketTimeout(15*1000).build();

		HttpHead head = new HttpHead(location);
		head.setConfig(rc);

		//设置请求头
		if (last_modified != null) {
			head.setHeader("If-Modified-Since", last_modified);
		}
		if (eTags != null) {
			head.setHeader("If-None-Match", eTags);
		}

		CloseableHttpResponse response = null;
		try {

			response = httpclient.execute(head);

			//返回200 才做操作
			if(response.getStatusLine().getStatusCode()==200){

				if (((response.getLastHeader("Last-Modified")!=null) && !response.getLastHeader("Last-Modified").getValue().equalsIgnoreCase(last_modified))
						||((response.getLastHeader("ETag")!=null) && !response.getLastHeader("ETag").getValue().equalsIgnoreCase(eTags))) {

					// 远程词库有更新,需要重新加载词典，并修改last_modified,eTags
					Dictionary.getSingleton().reLoadMainDict();
					last_modified = response.getLastHeader("Last-Modified")==null?null:response.getLastHeader("Last-Modified").getValue();
					eTags = response.getLastHeader("ETag")==null?null:response.getLastHeader("ETag").getValue();
				}
			}else if (response.getStatusLine().getStatusCode()==304) {
				//没有修改，不做操作
				//noop
			}else{
				logger.info("remote_ext_dict {} return bad code {}" , location , response.getStatusLine().getStatusCode() );
			}

		} catch (Exception e) {
			logger.error("remote_ext_dict {} error!",e , location);
		}finally{
			try {
				if (response != null) {
					response.close();
				}
			} catch (IOException e) {
				logger.error(e.getMessage(), e);
			}
		}
	}
监控流程：
①向词库服务器发送Head请求
②从响应中获取Last-Modify、ETags字段值，判断是否变化
③如果未变化，休眠1min，返回第①步
④如果有变化，重新加载词典
⑤休眠1min，返回第①步