LiquibaseStatusServlet.java example

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liquibase-master
package liquibase.integration.servlet;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.text.DateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.LogRecord;

/**
 * Servlet that can be registered via web.xml to view the log of the Liquibase run from the LiquibaseServletListener.
 */
public class LiquibaseStatusServlet extends HttpServlet {

    private static List<LogRecord> liquibaseRunLog = new ArrayList<LogRecord>();

    public static synchronized void logMessage(LogRecord message) {
        liquibaseRunLog.add(message);

    }

    @Override
    protected void doGet(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws ServletException, IOException {
        httpServletResponse.setContentType("text/html");

        String logLevelToDisplay = httpServletRequest.getParameter("logLevel");
        Level currentLevel = Level.INFO;
        if (logLevelToDisplay != null) {
            currentLevel = Level.parse(logLevelToDisplay);
        }

        PrintWriter writer = httpServletResponse.getWriter();
        writer.println("<html>");
        writer.println("<head><title>Liquibase Status</title></head>");
        writer.println("<body>");
        if (liquibaseRunLog.size() == 0) {
            writer.println("<b>Liquibase did not run</b>");
        } else {
            writer.println("<b>View level: " + getLevelLink(Level.SEVERE, currentLevel, httpServletRequest)
                    + " " + getLevelLink(Level.WARNING, currentLevel, httpServletRequest)
                    + " " + getLevelLink(Level.INFO, currentLevel, httpServletRequest)
                    + " " + getLevelLink(Level.CONFIG, currentLevel, httpServletRequest)
                    + " " + getLevelLink(Level.FINE, currentLevel, httpServletRequest)
                    + " " + getLevelLink(Level.FINER, currentLevel, httpServletRequest)
                    + " " + getLevelLink(Level.FINEST, currentLevel, httpServletRequest)
                    + "</b>");

            writer.println("<hr>");
            writer.println("<b>Liquibase started at " + DateFormat.getDateTimeInstance().format(new Date(liquibaseRunLog.get(0).getMillis())));
            writer.println("<hr>");
            writer.println("<pre>");
            for (LogRecord record : liquibaseRunLog) {
                if (record.getLevel().intValue() >= currentLevel.intValue()) {
                    writer.println(record.getLevel() + ": " + record.getMessage());
                    if (record.getThrown() != null) {
                        record.getThrown().printStackTrace(writer);
                    }
                }
            }
            writer.println("");
            writer.println("");

            writer.println("</pre>");
            writer.println("<hr>");
            writer.println("<b>Liquibase finished at " + DateFormat.getDateTimeInstance().format(new Date(liquibaseRunLog.get(liquibaseRunLog.size() - 1).getMillis())));
        }
        writer.println("</body>");
        writer.println("</html>");
    }

    private String getLevelLink(Level level, Level currentLevel, HttpServletRequest request) {
        if (currentLevel.equals(level)) {
            return level.getName();
        } else {
            return "<a href=" + request.getRequestURI() + "?logLevel=" + level.getName() + ">" + level.getName() + "</a>";
        }
    }
}