Spring Mvc with Thread - spring

Question

Hi My thread class is showing null pointer exception please help me to resolve
#Component
public class AlertsToProfile extends Thread {
public final Map<Integer, List<String>> userMessages = Collections.synchronizedMap(new HashMap<Integer, List<String>>());
#Autowired
ProfileDAO profileDAO;
private String categoryType;
private String dataMessage;
public String getCategoryType() {
return categoryType;
}
public void setCategoryType(String categoryType) {
this.categoryType = categoryType;
}
public String getDataMessage() {
return dataMessage;
}
public void setDataMessage(String dataMessage) {
this.dataMessage = dataMessage;
}
public void run() {
String category=getCategoryType();
String data= getDataMessage();
List<Profile> all = profileDAO.findAll();
if (all != null) {
if (category == "All" || category.equalsIgnoreCase("All")) {
for (Profile profile : all) {
List<String> list = userMessages.get(profile.getId());
if (list == null ) {
ArrayList<String> strings = new ArrayList<String>();
strings.add(data);
userMessages.put(profile.getId(), strings);
} else {
list.add(data);
}
}
}
}
}
and my service method is as follows
#Service
public class NoteManager
{
#Autowired AlertsToProfile alertsToProfile;
public void addNote(String type, String message, String category) {
alertsToProfile.setCategoryType(category);
String data = type + "," + message;
alertsToProfile.setDataMessage(data);
alertsToProfile.start();
System.out.println("addNotes is done");
}
But when i call start() method am getting null pointer exception please help me. I am new to spring with thread concept

Answer 1

It pretty obvious: you instantiate your thread directly, as opposed to letting spring create AlertsToProfile and auto wire your instance.
To fix this, create a Runnable around your run() method and embed that into a method, something like this:
public void startThread() {
new Thread(new Runnable() {
#Override
public void run() {
// your code in here
}}).start();
}
you will want to bind the Thread instance to a field in AlertsToProfile in order to avoid leaks and stop the thread when you're done.