D-Net

package eu.dnetlib.functionality.modular.ui;

import java.io.IOException;

import java.util.Enumeration;

import java.util.List;

import javax.annotation.PostConstruct;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.apache.log4j.Level;

import org.apache.log4j.LogManager;

import org.apache.log4j.Logger;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.ResponseBody;

import eu.dnetlib.functionality.modular.ui.utils.LogLine;

import eu.dnetlib.functionality.modular.ui.utils.LogUiAppender;

@Controller

public class DnetLogAjaxController extends AbstractAjaxController {

	private LogUiAppender appender;

	private static final Log log = LogFactory.getLog(DnetLogAjaxController.class);

	@PostConstruct

	void init() throws IOException {

		this.appender = findLogUiAppender();

	}

	private LogUiAppender findLogUiAppender() {

		final Logger logger = LogManager.getRootLogger();

		final Enumeration<?> appenders = logger.getAllAppenders();

		while (appenders.hasMoreElements()) {

			final Object app = appenders.nextElement();

			if (app instanceof LogUiAppender) {

				log.info("An istance of LogUiAppender is already registered in log4j configuration.");

				return (LogUiAppender) app;

			}

		}

		final LogUiAppender app = new LogUiAppender();

		LogManager.getRootLogger().addAppender(app);

		log.info("A new LogUiAppender has been registered in log4j configuration.");

		return app;

	}

	@RequestMapping(value = "/ui/log/tail/{n}")

	public @ResponseBody List<LogLine> tail_N(@PathVariable(value = "n") final int n) throws Exception {

		return this.appender.tail_N(n);

	}

	@RequestMapping(value = "/ui/log/continue/{after}")

	public @ResponseBody List<LogLine> tail_continue(@PathVariable(value = "after") final int after) throws Exception {

		return tail_continue(after, 0);

	}

	private List<LogLine> tail_continue(final int after, final int recursionLevel) throws Exception {

		final List<LogLine> res = this.appender.tail_continue(after);

		if (res.isEmpty() && recursionLevel < 10) {

			Thread.sleep(10000);

			return tail_continue(after, recursionLevel + 1);

		} else {

			return res;

		}

	}

	@RequestMapping(value = "/ui/log/level/{level}/{resource}")

	public @ResponseBody boolean updateLogLevel(@PathVariable(value = "level") final String level, @PathVariable(value = "resource") final String resource)

			throws Exception {

		if (resource != null && level != null) {

			LogManager.getLogger(resource).setLevel(Level.toLevel(level));

		}

		return true;

	}

}