001 package org.wdssii.webindex.servlet;
002
003 import java.io.IOException;
004 import java.io.PrintWriter;
005
006 import javax.servlet.http.HttpServletRequest;
007 import javax.servlet.http.HttpServletResponse;
008
009 import org.apache.commons.logging.Log;
010 import org.apache.commons.logging.LogFactory;
011 import org.springframework.validation.BindException;
012 import org.springframework.web.servlet.ModelAndView;
013 import org.springframework.web.servlet.mvc.AbstractCommandController;
014
015 public class WebIndexController extends AbstractCommandController {
016 private WebIndexFactory indexFactory;
017 private SourcesListingDAO sourcesDAO;
018 private final Log log = LogFactory.getLog(getClass());
019
020 public static class Command {
021 private String source = null;
022 private long lastRead = IndexRecordList.RETURN_ALL_RECORDS; // default value if lastRead not set
023 public String getSource() {
024 return source;
025 }
026 public void setSource(String sourceName) {
027 this.source = sourceName;
028 }
029 public long getLastRead() {
030 return lastRead;
031 }
032 public void setLastRead(long lastRead) {
033 this.lastRead = lastRead;
034 }
035 }
036
037
038 public WebIndexController(WebIndexFactory factory, SourcesListingDAO sourcesDAO){
039 this.indexFactory = factory;
040 this.sourcesDAO = sourcesDAO;
041 setCommandClass(WebIndexController.Command.class);
042 }
043
044 @Override
045 protected ModelAndView handle(HttpServletRequest request, HttpServletResponse response, Object command_, BindException errors) throws Exception {
046 if (errors.hasErrors()){
047 return new ModelAndView("showErrors", "errors", errors.getAllErrors());
048 }
049
050 Command command = (Command) command_;
051 String source = command.getSource();
052 long lastRead = command.getLastRead();
053
054 if ( log.isDebugEnabled() ){
055 log.debug("looking for next records from " + source + " lastRead=" + lastRead);
056 }
057 if ( source == null ){
058 String[] sources = sourcesDAO.getAllSources();
059 if ( log.isDebugEnabled() ){
060 log.debug("Sending along " + sources.length + " sources");
061 }
062 return new ModelAndView("showSources", "sources", sources );
063 }
064
065 WebIndexDAO indexDAO = indexFactory.getDAO(source);
066 IndexRecordList to = indexDAO.getCurrentRecordList(lastRead);
067 if ( log.isDebugEnabled() ){
068 log.debug("Returning " + to.getRecords().length + " records in response to request");
069 }
070 return generateResponse(response, to);
071 }
072
073 /** this method is in the controller because it is too inefficient to perform in the JSP */
074 private ModelAndView generateResponse(HttpServletResponse response, final IndexRecordList to) throws IOException
075 {
076 long startTime = System.currentTimeMillis();
077 PrintWriter out = response.getWriter();
078
079 final IndexRecordBean[] records = to.getRecords();
080 final long lastRead = to.getLastNumber();
081 final String source = to.getSource();
082
083 response.setContentType("text/xml");
084 out.print("<records source=\"");
085 out.print(source);
086 out.print("\" lastRead=\"");
087 out.print(lastRead);
088 out.print("\" listsize=\"");
089 out.print(records.length);
090 out.println("\">");
091 for (IndexRecordBean record : records){
092 out.println(record.getXML());
093 }
094 out.println("</records>");
095 long endTime = System.currentTimeMillis();
096 if ( log.isDebugEnabled() ){
097 log.debug("Took " + (endTime-startTime) + " milliseconds to render response XML");
098 }
099 return null; // for ModelAndView, to indicate nothing further needs to be done
100 }
101
102 }