zarty zarty - 1 month ago 9
Java Question

Invoke the doGet Servlet method from java class

I have a scheduled job class, implements the Quartz Job class, from which I want to invoke a Servlet class that updates a flag in a DB table and then it sends emails to an appropriate emailing list.

I get a

java.net.ConnectException
. Though the servlet is properly invoked by either entering its URL in the browser or by JavaScript in a JSP page.

My Java class is the following:

public class ExpirationJob implements Job {
org.apache.log4j.Logger log = org.apache.log4j.Logger.getLogger("ExpirationJob.class");

public void execute(JobExecutionContext context)
throws JobExecutionException {
try {
URL serv = new URL("http://localhost:8080/app/emailExpirationServlet");
URLConnection sr = serv.openConnection();
sr.connect();
InputStream is = sr.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader in = new BufferedReader(isr);

String inputLine;
int i =0;
while ((inputLine = in.readLine()) != null)
i = i +1;
log.debug("Input line: " + inputLine);
in.close();
} catch (MalformedURLException e) {
log.debug("Error while calling the emailExpirationServlet -- MalformedURLException: "+ e.getMessage());
e.printStackTrace();
} catch (IOException e) {
log.debug("Error while calling the emailExpirationServlet -- IOException: "+ e.getMessage());
e.printStackTrace();
}
}
}


My servlet code is:

public class emailExpireServlet extends HttpServlet {
private static final String CONTENT_TYPE = "text/html; charset=UTF-8";
org.apache.log4j.Logger log = org.apache.log4j.Logger.getLogger("emailExpireServlet.class");

public void init(ServletConfig config) throws ServletException {
super.init(config);
log.debug("Initializing emailExpireServlet");
}

public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

request.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
response.setDateHeader("Expires", 0);
response.setHeader("Cache-Control", "no-cache");
log.debug("Starting emailExpireServlet");

//do some business logic here - I have commented it out to rule out any other blocking issue
response.setStatus(200);
response.getOutputStream().print("Invoked emailExpireServlet! Status is OK");

}

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}


The exception I get is:

java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:525)
at java.net.Socket.connect(Socket.java:475)
at sun.net.NetworkClient.doConnect(NetworkClient.java:163)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:394)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:529)
at sun.net.www.http.HttpClient.<init>(HttpClient.java:233)
at sun.net.www.http.HttpClient.New(HttpClient.java:306)
at sun.net.www.http.HttpClient.New(HttpClient.java:323)
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:860)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:801)
at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:726)
at schedulers.ExpirationJob.execute(Unknown Source)
at org.quartz.core.JobRunShell.run(JobRunShell.java:213)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:557)


I am using Tomcat 5.5.

I have seen lots of other relative posts but did not help, I also tried with
HttpClient
but the same exception.

Could anyone figure out what the problem is?

The servlet configuration on the
web.xml
is:

<servlet>
<servlet-name>emailExpireServlet</servlet-name>
<servlet-class>emailExpireServlet</servlet-class>
</servlet>
...
<servlet-mapping>
<servlet-name>emailExpireServlet</servlet-name>
<url-pattern>/emailExpireServlet</url-pattern>
</servlet-mapping>

Answer

You should refactor your code to move this functionality out of the servlet and into a common class that can be reached both from your servlet and from your scheduled job.