转载文章，转载自，公司项目，董亚杰写的。

下面是完整的代码，复制的。

package cn.digitalpublishing.util.debug;import java.io.File;
import java.nio.file.FileSystems;
import java.nio.file.Paths;
import java.nio.file.StandardWatchEventKinds;
import java.nio.file.WatchEvent;
import java.nio.file.WatchEvent.Kind;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;import org.apache.commons.io.FilenameUtils;import cn.digitalpublishing.util.SpringUtils;import com.ingenta.framework.dao.impl.support.DefaultIngentaDao;/*** * @author dongyajie**/
@WebServlet(initParams = { @WebInitParam(name = "path", value = "W:\\workspace2\\Editorial\\src\\main\\resources\\sql") }, value = "/DynamicReloadHqlXmlNew", loadOnStartup = 88)
public class DynamicReloadHqlXmlNew extends HttpServlet {private static final long serialVersionUID = 1L;private final String ACTION_ENTRY_CREATE = "ENTRY_CREATE";private final String ACTION_ENTRY_DELETE = "ENTRY_DELETE";private final String ACTION_ENTRY_MODIFY = "ENTRY_MODIFY";private String prevFileName = "";private String prevAction = "";private long prevTimeMillis = 0;private final long interval = 500;private DefaultIngentaDao dao;@Overridepublic void init(ServletConfig config) throws ServletException {final String hqlDir = config.getInitParameter("path");dao = (DefaultIngentaDao) SpringUtils.getBean("ingentaDao");ExecutorService service = Executors.newSingleThreadExecutor();service.execute(new Runnable() {@Overridepublic void run() {WatchService watchService = null;try {watchService = FileSystems.getDefault().newWatchService();Paths.get(hqlDir).register(watchService, StandardWatchEventKinds.ENTRY_CREATE, StandardWatchEventKinds.ENTRY_DELETE, StandardWatchEventKinds.ENTRY_MODIFY);} catch (Exception e) {}if (watchService != null) {while (true) {try {WatchKey key = watchService.take();List<WatchEvent<?>> events = key.pollEvents();if (!events.isEmpty()) {WatchEvent<?> event = events.get(events.size() - 1);File eventFile = new File(hqlDir, event.context().toString());Kind<?> eventKind = event.kind();String kindName = eventKind.name();if (eventKind.name().equals(ACTION_ENTRY_CREATE)) {kindName = ACTION_ENTRY_MODIFY;}if ((!eventFile.getPath().equals(prevFileName) || !kindName.equals(prevAction)) || ((System.currentTimeMillis() - prevTimeMillis) > interval)) {if (eventFile.isFile()) {if (kindName.equals(ACTION_ENTRY_MODIFY)) {if (FilenameUtils.isExtension(eventFile.getName().toLowerCase(), "xml")) {loadXML(eventFile.getPath());}}}if (kindName.equals(ACTION_ENTRY_DELETE)) {}prevAction = kindName;prevFileName = eventFile.getPath();prevTimeMillis = System.currentTimeMillis();}}if (!key.reset()) {break;}} catch (Exception e) {}}}}});service.shutdown();}private synchronized void loadXML(String filename) {String logfn = FilenameUtils.getName(filename);try {dao.loadResource(new File(filename));System.err.println(logfn + " 加载完成");} catch (Exception e) {System.err.println(logfn + " 加载失败" + e.getMessage());}}
}

反正，暂时我是看不懂，感觉太高端了，总有一天我有看懂的时候，，，，，

大神，工作经验5年，编程经验，10年，90后。