GetPVTypeInfo.java

package org.epics.archiverappliance.mgmt.bpl;

import java.io.IOException;
import java.io.PrintWriter;

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.config.ConfigService;
import org.epics.archiverappliance.config.PVTypeInfo;
import org.epics.archiverappliance.utils.ui.JSONEncoder;
import org.epics.archiverappliance.utils.ui.MimeTypeConstants;

/**
 * Gets the type info for a PV as a JSON object
 * 
 * @epics.BPLAction - Get the type info for a given PV. In the archiver appliance terminology, the PVTypeInfo contains the various archiving parameters for a PV. 
 * @epics.BPLActionParam pv - The name of the pv.
 * @epics.BPLActionEnd
 * @author mshankar
 *
 */
public class GetPVTypeInfo implements BPLAction {
	private static Logger logger = Logger.getLogger(GetPVTypeInfo.class.getName());

	@Override
	public void execute(HttpServletRequest req, HttpServletResponse resp, ConfigService configService) throws IOException {
		String pvName = req.getParameter("pv");
		logger.debug("Getting typeinfo for PV " + pvName);
		if(pvName == null || pvName.equals("")) {
			resp.sendError(HttpServletResponse.SC_NOT_FOUND);
			return;
		}

		// String pvNameFromRequest = pvName;
		String realName = configService.getRealNameForAlias(pvName);
		if(realName != null) pvName = realName;

		PVTypeInfo typeInfo = configService.getTypeInfoForPV(pvName);
		if(typeInfo == null) {
			logger.warn("Cannot find typeinfo for " + pvName);
			resp.sendError(HttpServletResponse.SC_NOT_FOUND);
			return;
		}
		resp.setContentType(MimeTypeConstants.APPLICATION_JSON);
		try (PrintWriter out = resp.getWriter()) {
			JSONEncoder<PVTypeInfo> jsonEncoder = JSONEncoder.getEncoder(PVTypeInfo.class);
			out.println(jsonEncoder.encode(typeInfo));
		} catch(Exception ex) {
			logger.error("Exception marshalling typeinfo for pv " + pvName, ex);
			resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
		}
	}
}