RecentlyAddedPVsforThisInstance.java

package org.epics.archiverappliance.mgmt.bpl.reports;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Timestamp;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.LinkedList;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.epics.archiverappliance.common.BPLAction;
import org.epics.archiverappliance.common.TimeUtils;
import org.epics.archiverappliance.config.ConfigService;
import org.epics.archiverappliance.config.PVTypeInfo;
import org.json.simple.JSONArray;
import org.json.simple.JSONAware;
import org.json.simple.JSONValue;

/**
 * Generate a report of PVs recently added to this instance....
 * @author mshankar
 *
 */
public class RecentlyAddedPVsforThisInstance implements BPLAction {
	private static Logger logger = Logger.getLogger(RecentlyAddedPVsforThisInstance.class.getName());

	@Override
	public void execute(HttpServletRequest req, HttpServletResponse resp, final ConfigService configService) throws IOException {
		String limitStr = req.getParameter("limit");
		int limit = 100;
		logger.info("Recently added PVs report for this instance for " + (limitStr == null ? ("default limit(" + limit + ")") : ("limit " + limitStr)));
		if(limitStr != null) {
			limit = Integer.parseInt(limitStr);
		}
		
		final String identity = configService.getMyApplianceInfo().getIdentity();
		final class RecentlyAddedPVInfo implements JSONAware {
			String pvName;
			Timestamp creationTimeStamp;

			RecentlyAddedPVInfo(String pvName, Timestamp creationTimeStamp) {
				this.pvName = pvName;
				this.creationTimeStamp = creationTimeStamp;
			}

			@Override
			public String toJSONString() {
				HashMap<String, String> jsonObj = new HashMap<String, String>();
				jsonObj.put("pvName", pvName);
				jsonObj.put("instance", identity);
				jsonObj.put("creationTime", TimeUtils.convertToHumanReadableString(this.creationTimeStamp));
				return JSONValue.toJSONString(jsonObj);
			}
		}
		
		LinkedList<RecentlyAddedPVInfo> myPVs = new LinkedList<RecentlyAddedPVInfo>();
		for(String pv : configService.getPVsForThisAppliance()) {
			PVTypeInfo typeInfo = configService.getTypeInfoForPV(pv);
			if(typeInfo != null) { 
				myPVs.add(new RecentlyAddedPVInfo(pv, typeInfo.getCreationTime()));
			}
		}
		
		Collections.sort(myPVs, new Comparator<RecentlyAddedPVInfo>() {
			@Override
			public int compare(RecentlyAddedPVInfo o1, RecentlyAddedPVInfo o2) {
				return o2.creationTimeStamp.compareTo(o1.creationTimeStamp);
			}
		});
		
		try(PrintWriter out = resp.getWriter()){ 
			out.println(JSONArray.toJSONString(myPVs.subList(0, Math.min(limit, myPVs.size()))));
		}
	}
}