I need to create 2 instances that run the same SQL procedure but with different parameters.
public void run() {
// TRUE if there is no more VER_STOCK
boolean booEsgotado = false;
System.out.println("Starting thread" + numThread );
try {
objLigacao = DriverManager.getConnection(LIGACAO,
UTILIZADOR, SENHA);
// manual control of transactions
objLigacao.setAutoCommit(false);
while (booEsgotado == false && i<=5) {
try {
objComando = objLigacao.prepareCall(INSERE);
// 1 = first parameter (:1)
objComando.setInt(1, ID);
objComando.setInt(2, PRODUTO);
objComando.setInt(3, Q);
objComando.execute();
objComando.close();
// If done with success commit the operations
objLigacao.commit();
i++;
System.out.println("Sold a unit in thread " + numThread + " i = " + i);
objComando = objLigacao.prepareCall(QUANT);
objComando.setInt(1, PRODUTO);
objResultado = objComando.executeQuery();
while(objResultado.next()) {
stock=objResultado.getInt(1);}
System.out.println("Stock atual=" + stock);
}
catch (SQLException objExcepcao) {
System.out.println("" + objExcepcao.getMessage());
// If something failed rollback the operations
objComando.close();
objLigacao.rollback();
booEsgotado = true;
System.out.println("Product is out of stock in thread" + numThread);
}
}
// Libertação de recursos.
objLigacao.close();
} catch (SQLException objExcepcao) {
System.out.println(objExcepcao.getMessage());
}
System.out.println("The end of thread " + numThread );
}
The thing is that I can only run the same procedure with the same arguments in both instances. Where I need to execute the same procedure but with different arguments in both instances.
runne1 objInstancia1 = new runne1(1);
runne1 objInstancia2 = new runne1(2);
// Create a thread for each instance
Thread objThread1 = new Thread(objInstancia1);
Thread objThread2 = new Thread(objInstancia2);
objThread1.start();
objThread2.start();
try {
objThread1.join();
objThread2.join();
Subclass Thread to provide a constructor that specifies parameters you need and store them as instance fields.
In this way, you could use them in the run() method.
public class MyCallThread extends Thread {
private int paramOne;
private int paramTwo;
public MyCallThread (Runnable runnable, int paramOne, int paramTwo){
super(runnable);
this.paramOne = paramOne;
this.paramTwo = paramTwo;
}
public void run(){
...
objComando.setInt(1, paramOne);
...
}
}
And instantiate it like that :
int paramOne = ...;
int paramTwo = ...;
Thread objThread1 = new MyCallThread(objInstancia1, paramOne, paramTwo);
...
Related
Hi i have a race condition in given method i have 2 instances in kubernates and checking in redis
public void method(GuestDTO guestDTO) {
String executeName = "addingGuestToCache" + guestDTO.getUser();
if (!redisService.checkExecute(executeName)) {
redisService.startExecute(executeName);
OpenGuestDTO openGuestDTO = new OpenGuestDTO();
RMap<String, List<OpenGuestDTO>> openGuestDTOList = redisService.getOpenGuestDTOList();
List<OpenGuestDTO> userGuestList = openGuestDTOList.get(guestDTO.getUser());
if (userGuestList == null) {
userGuestList = Collections.synchronizedList(new ArrayList<OpenGuestDTO>());
}
for (OpenGuestDTO guestDTO1 : userGuestList) {
if (guestDTO1.getGuestName().equalsIgnoreCase(guestDTO.getGuestName())) {
redisService.deleteExecute(executeName);
return;
}
}
openGuestDTOList.add(openGuestDTO);
openGuestDTOList.fastPut(guestDTO.getUser(), userGuestList);
redisService.deleteExecute(executeName);
}else{
method(guestDTO);
}
}
Hi everyone i've produced an agent based model. The agents can move randomly and use the A* algorithm to move to places to places. There are two main collections 1) arrival Queue (arraylist) and the 2) main agents (arraylist). All the agents are initially placed into the arrival queue, agents are placed into the simulation at certain time intervals e.g. 100 agents per 400 simulation steps).
The issue im getting is every time I increase the population of agents from 3000+ the simulation begins to lag. Also im using the Java 2D libraries for visualizing the 2D array of agents. Bellow ive added a screenshot of the the visualVM of my application is shows the methods which are being called the most (CPU time).
ScreenShot Here
Model code:
package Model;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import Model.Grid;
import Agent.*;
public class Model extends AbstractModel implements Runnable{
private Grid grid;
private Constants modelConstants;
private RandomGenerator randGenerator;
private GridMapLayout Maplayout;
private RoomController roomController;
private AgentFactory agentFacory;
private Statistics stats;
private ArrayList<AbstractAgent> agents;
private Queue<Patient> patientArrivalQueue;
private List<Patient> dischargedPatients;
private Queue<Doctor> doctorsQueue;
private Queue<Nurse> nursesQueue;
private int patientPopulation;
private int doctorPopulation;
private int receptionNurses;
private int aNeNurses;
private int ward1Nurses;
private int ward2Nurses;
private int ward3Nurses;
private boolean running;
private int currentSimCycle;
private int simArrivalCounter;
public CTimer timer = new CTimer();
public Model() {
super();
this.grid = new Grid(150, 150); //if no given size grid uses default size
this.modelConstants = new Constants();
this.randGenerator = new RandomGenerator(modelConstants.getSEED());
this.Maplayout = new GridMapLayout(this);
this.roomController = new RoomController(this);
this.agentFacory = new AgentFactory(this);
this.stats = new Statistics(this);
this.currentSimCycle = 0;
this.simArrivalCounter = 0;
this.agents = new ArrayList<AbstractAgent>();
this.patientArrivalQueue = new LinkedList<Patient>();
this.dischargedPatients = new LinkedList<Patient>();
this.doctorsQueue = new LinkedList<Doctor>();
this.nursesQueue = new LinkedList<Nurse>();
loadModelConstants();
loadMapLayout();
roomController.readyRoomCollections();
createAllAgents();
loadDoctorsInRooms();
loadNursesInRooms();
loadNextPatientArrival();
// randomlyPopulateGrid();
stats.updateStatistics();
stats.setDataValid(false);
// Room entrance = roomController.getAllRooms().get("Entrance");
// Room reception = roomController.getAllRooms().get("Reception");
// Room aNe = roomController.getAllRooms().get("A&E");
// Room ward1 = roomController.getAllRooms().get("Ward 1");
// Room ward2 = roomController.getAllRooms().get("Ward 2");
// Room ward3 = roomController.getAllRooms().get("Ward 3");
// Room canteen = roomController.getAllRooms().get("Canteen");
// Room toilet = roomController.getAllRooms().get("Toilet");
//
// System.out.println(toilet);
// System.out.println(entrance.getDoorLocations().size());
// System.out.println("Reception: " + reception.getRoomLocations().size());
// System.out.println("A&E: " + aNe.getRoomLocations().size());
// System.out.println("Ward 1: " + ward1.getRoomLocations().size());
// System.out.println("Ward 2: " + ward2.getRoomLocations().size());
// System.out.println("Ward 3: " + ward3.getRoomLocations().size());
// System.out.println("Canteen: " + canteen.getRoomLocations().size());
// System.out.println("Toilet: " + toilet.getRoomLocations().size());
}
public void loadModelConstants() {
this.patientPopulation = modelConstants.getPatientPopulation();
this.doctorPopulation = modelConstants.getDoctorPopulation();
this.receptionNurses = modelConstants.getReceptionNursePopulation();
this.aNeNurses = modelConstants.getaNeNursePopulation();
this.ward1Nurses = modelConstants.getWard1NursePopulation();
this.ward2Nurses = modelConstants.getWard2NursePopulation();
this.ward3Nurses = modelConstants.getWard3NursePopulation();
// System.out.println(this.patientPopulation);
// System.out.println(this.doctorPopuation);
// System.out.println(this.nursePopulation);
System.out.println("Loaded Model Constants");
}
public void loadMapLayout() {
Maplayout.loadMapImage();
Maplayout.loadRGBfileAndRooms();
Maplayout.readPixels();
Maplayout.addMapLayout();
// layout.printCells();
System.out.println("Loaded Map Layout");
}
public void createAllAgents() {
ArrayList<Patient> tempPatient = new ArrayList<Patient>();
ArrayList<Doctor> tempDoctor = new ArrayList<Doctor>();
ArrayList<Nurse> tempNurse = new ArrayList<Nurse>();
int totalNurses = + (modelConstants.getReceptionNursePopulation()
+ modelConstants.getaNeNursePopulation()
+ modelConstants.getWard1NursePopulation()
+ modelConstants.getWard2NursePopulation()
+ modelConstants.getWard3NursePopulation()
);
int noOfAgentLeftToCreate = modelConstants.getPatientPopulation() + modelConstants.getDoctorPopulation()
+ totalNurses;
while(tempPatient.size() != this.patientPopulation) {
Patient newPatient = (Patient) this.agentFacory.createAgent("PATIENT", noOfAgentLeftToCreate);
tempPatient.add(newPatient);
noOfAgentLeftToCreate--;
}
while(tempDoctor.size() != this.doctorPopulation) {
Doctor newDoctor = (Doctor)this.agentFacory.createAgent("DOCTOR", noOfAgentLeftToCreate);
tempDoctor.add(newDoctor);
noOfAgentLeftToCreate--;
}
while(tempNurse.size() != totalNurses) {
Nurse newNurse = (Nurse)this.agentFacory.createAgent("NURSE", noOfAgentLeftToCreate);
tempNurse.add(newNurse);
noOfAgentLeftToCreate--;
}
this.patientArrivalQueue.addAll(tempPatient); //Add total patients to arrive queue
this.doctorsQueue.addAll(tempDoctor); //Add all doctors to the doctors agent collection
this.nursesQueue.addAll(tempNurse); //Add all nurses to the nurse agent collection
System.out.println("All agents created");
}
public void loadDoctorsInRooms() {
for(Map.Entry<String, Room> pair : roomController.getDoctorRooms().entrySet()) {
String key = pair.getKey();
Room value = pair.getValue();
if(value.isRoomEmpty()) {
Doctor newDoctor = doctorsQueue.remove();
Location randFreeRoomLoc = value.getRandomFreeRoomLocation();
grid.moveAgentToNewLocation(newDoctor, newDoctor.getLocation(), randFreeRoomLoc);
newDoctor.setLocation(randFreeRoomLoc);
newDoctor.setAllocatedRoom(value);
newDoctor.getAgentController().setCurrentRoom(value);
newDoctor.getAgentController().setTargetRoom(value);
//Tell the room that this agent is now a occupant of the room
value.getCurrentOccupantsMap().put(newDoctor.getAgentID(), newDoctor);
agents.add(newDoctor);
}
}
Room aNeRoom = roomController.getAllRooms().get("A&E");
if(aNeRoom.isRoomEmpty()) {
Doctor aNeDoc = doctorsQueue.remove();
Location randFreeRoomLoc = aNeRoom.getRandomFreeRoomLocation();
grid.moveAgentToNewLocation(aNeDoc, aNeDoc.getLocation(), randFreeRoomLoc);
aNeDoc.setLocation(randFreeRoomLoc);
aNeDoc.setAllocatedRoom(aNeRoom);
aNeDoc.getAgentController().setCurrentRoom(aNeRoom);
aNeDoc.getAgentController().setTargetRoom(aNeRoom);
//Tell the room that this agent is now a occupant of the room
aNeRoom.getCurrentOccupantsMap().put(aNeDoc.getAgentID(), aNeDoc);
agents.add(aNeDoc);
}
System.out.println("All Doctors are placed");
}
public void loadNursesInRooms() {
HashMap<String, Room> nurseRooms = new HashMap<String, Room>();
nurseRooms.putAll( roomController.getAllRooms());
nurseRooms.remove("Toilet");
nurseRooms.remove("Canteen");
nurseRooms.remove("Staff");
nurseRooms.remove("Corridor");
nurseRooms.remove("ISOL Entrance");
nurseRooms.remove("Entrance");
nurseRooms.remove("Exit");
for(Map.Entry<String, Room> drPair : roomController.getDoctorRooms().entrySet()) {
String drKey = drPair.getKey();
Room drValue = drPair.getValue();
for(Map.Entry<String, Room> isolPair : roomController.getIsolRooms().entrySet()) {
String isolKey = isolPair.getKey();
Room isolValue = isolPair.getValue();
if(nurseRooms.containsKey(drKey)) {
nurseRooms.remove(drKey);
}
if(nurseRooms.containsKey(isolKey)) {
nurseRooms.remove(isolKey);
}
}
}
for(Map.Entry<String, Room> pair : nurseRooms.entrySet()) {
String key = pair.getKey();
Room value = pair.getValue();
int noOfNurseToCreate = 0;
if(key.contentEquals("Reception")) {
noOfNurseToCreate = modelConstants.getReceptionNursePopulation();
}
else if(key.contentEquals("A&E")) {
noOfNurseToCreate = modelConstants.getaNeNursePopulation();
}
else if(key.contentEquals("Ward 1")) {
noOfNurseToCreate = modelConstants.getWard1NursePopulation();
}
else if(key.contentEquals("Ward 2")) {
noOfNurseToCreate = modelConstants.getWard2NursePopulation();
}
else if(key.contentEquals("Ward 3")) {
noOfNurseToCreate = modelConstants.getWard3NursePopulation();
}
for(int i=0; i != noOfNurseToCreate; i++) {
Nurse newNurse = nursesQueue.remove();
Location roomLocation = value.getRandomFreeRoomLocation();
grid.moveAgentToNewLocation(newNurse, newNurse.getLocation(), roomLocation);
newNurse.setLocation(roomLocation);
newNurse.setAllocatedRoom(value);
newNurse.getAgentController().setCurrentRoom(value);
newNurse.getAgentController().setTargetRoom(value);
//Tell the room controller that this agent is now an occupant of the room
value.getCurrentOccupantsMap().put(newNurse.getAgentID(), newNurse);
agents.add(newNurse);
}
}
System.out.println("All Nurses are placed");
}
public void loadNextPatientArrival() {
if(this.simArrivalCounter == 0) {
int removeThemPatients = 0;
//If there are more patients in the arrival queue then the specified simPatientarrival rate then
//remove the specified amount of patients per simPatient arrival rate
if(patientArrivalQueue.size() >= modelConstants.getPatientArrivalRate()) {
removeThemPatients = modelConstants.getPatientArrivalRate();
}
//Number of patient to place on the grid is less then the patient arrival rate, just place the rest into the entrance
else {
removeThemPatients = patientArrivalQueue.size();
}
Room reception = roomController.getAllRooms().get("Reception");
Room aNe = roomController.getAllRooms().get("A&E");
for(int i=removeThemPatients; i !=0; i--) {
Patient nextPatient = patientArrivalQueue.remove();
// if(nextPatient.getPatientType().contains("Normal") & nextPatient.getLocation() != null) {
if(grid.checkEmptyAt(nextPatient.getLocation())) {
grid.placeAgent(nextPatient, nextPatient.getLocation());
agents.add(nextPatient);
}
else {
patientArrivalQueue.add(nextPatient);
}
// }
}
//IMPORTANT need to reset the simArrivalCounter back to the specified count
this.simArrivalCounter = this.modelConstants.getSimArrivalCounter();
// System.out.println("More patients have arrived");
}
}
public void removeDischargedPatients() {
//Just iterate through the exit room door locations and remove
//the the discharged patients waiting there into the patient discharge list
Room exit = roomController.getAllRooms().get("Exit");
for(Location loc : exit.getDoorLocations()) {
if(!grid.checkEmptyAt(loc)) {
Patient dischargedPatient = (Patient) grid.getAgentAtLocation(loc);
grid.clearLocationAt(loc);
agents.remove(dischargedPatient);
dischargedPatients.add(dischargedPatient);
}
}
}
public void randomlyPopulateGrid() {
Room reception = roomController.getAllRooms().get("Reception");
while(!this.patientArrivalQueue.isEmpty()) {
Location freeLoc = reception.getRandomFreeRoomLocation();
Patient nextPatient = this.patientArrivalQueue.remove();
grid.moveAgentToNewLocation(nextPatient, nextPatient.getLocation(), freeLoc);
nextPatient.setLocation(freeLoc);
nextPatient.getAgentController().setCurrentRoom(reception);
nextPatient.getAgentController().setTargetRoom(reception);
agents.add(nextPatient);
}
System.out.println("Populate Grid");
}
public void simulateCycles(int maxCycles) {
for(int i=0; i != maxCycles; i++) {
loadNextPatientArrival();
removeDischargedPatients();
updateAgents();
stats.updateStatistics();
stats.setDataValid(false);
this.currentSimCycle++;
this.simArrivalCounter--;
}
notifyViews();
}
public void updateAgents() {
// Iterator<AbstractAgent> it = agents.iterator();
// while(it.hasNext()) {
// AbstractAgent nextAgent = it.next();
// nextAgent.act();
// }
for(AbstractAgent agent : agents) {
agent.act();
}
}
#Override
public void startSimulation() {
new Thread(this).start();
System.out.println("Running Simulation");
}
#Override
public void stopSimulation() {
running = false;
System.out.println("Simulation has stoped");
}
#Override
public void resetSimulation() {
System.out.println("Model Constant set to default");
}
public void run() {
running = true;
// int loop = 0;
while(running) {
// System.out.println("loop: "+ loop);
// loop++;
simulateCycles(1);
try {
Thread.sleep(5);
}
catch (Exception e) {
}
}
}
public Grid getGrid() {
return grid;
}
public List<AbstractAgent> getAgentsCollection() {
return agents;
}
public GridMapLayout getGridMayLayout() {
return Maplayout;
}
public RoomController getRoomController() {
return roomController;
}
public Constants getModelConstants() {
return modelConstants;
}
public RandomGenerator getRandGenerator() {
return randGenerator;
}
public int getCurrentSimCycle() {
return currentSimCycle;
}
public Statistics getStats() {
return stats;
}
}
This is a characteristic of time-stepped agent-based modeling. Since each of n agents can in principle interact with any of the other agents, there are n choose 2 interactions to be evaluated at each time step, which grows as O(n2). Your basic choices are: 1) keep the number of agents small; 2) increase the size of your time steps (which usually introduces modeling errors due to the coarser approximation of what's happening); 3) "localize" the scope of interactions (which may or may not be realistic for what you're modeling); or 4) rewrite your model to use discrete event scheduling rather than time stepping.
Following is my main class.
public class ShareData {
/**
* #param args
*/
public static void main(String[] args) {
ShareReader aShareReader = new ShareReader("http://test.com:9000", "dilip.id#gmail.com", "password");
Thread fileThread = new Thread(aShareReader);
fileThread.run(); // fileThread.start() not calling the run() method
}
}
If I type fileThread.run() run method is called. If I call fileThread.start() the run metod is not called. Following is my thread class. I dont know what I am doing wrong.
public class ShareReader implements Runnable {
private String itsShareURL = null;
private String itsUserId = null;
private String itsPassword = null;
private String itsAuthToken = null;
private String itsLoginURL = null;
private String itsChannelUpateURL = null;
/**
*
*/
public ShareReader(String theShareURL, String theUserId, String thePassword) {
this.itsShareURL = theShareURL;
this.itsUserId = theUserId;
this.itsPassword = thePassword;
this.itsLoginURL = itsShareURL + "/v1.0-SNAPSHOT/login";
this.itsChannelUpateURL = itsShareURL + "/v1.0-SNAPSHOT/updateChannelSubscription/";
}
public void run() {
JSONObject json;
JSONArray jsonArray;
itsAuthToken = getToken(itsUserId, itsPassword);
updateChannelList(itsAuthToken);
String aURL = "http://test.com:9000/v1.0-SNAPSHOT/userTimeline/"+itsAuthToken+"/";
try {
String lat = null;
String lon = null;
String udid = null;
String dateTime = null;
String eventID = null;
aEventBean = new EventBean();
jsonArray = readJsonArrayFromUrl(aURL);
for (int i = 0; i < jsonArray.length(); i++) {
json = jsonArray.getJSONObject(i);
lat = json.getString("lat");
lon = json.getString("lon");
udid = json.getString("udid");
eventID = json.getString("eventId");
dateTime = json.getString("dateTime");
aEventBean.setItsLatitude(lat);
aEventBean.setItsLongitude(lon);
aEventBean.setItsUDID(udid);
aEventBean.setItsEventIdentifier(eventID);
aEventBean.setItsDateTime(dateTime);
System.out.println(udid + " ---> " +lat + " ==== " + lon);
sendData(aEventBean);
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
Sorry If I ask so basic question..
Ideally I need to do fileThread.start() to start a thread..
Thanks in advance...
run() is definitely called if you call start() on fileThread. Check your implementation of run()- its very likely that this method completes or terminates before your check for the print statements. Just an fyi, fileThread.run() is a sequential call while fileThread.start() is a parallel call.
Another vague possibility is that you're not implementing Java's runnable; instead, that may be some custom Runnable class in your project.
EDIT:
So apparently calling fileThread.join() helped you fix your problem, but why does this work? If you call fileThread.join(), the main thread waits until the target (in this case, your fileThread object) terminates.
fileThread.run() never starts a new thread. To start a new thread you have to call fileThread.start().
I have been trying to work through the HelloAndroid example for ORMLite but haven't been able to successfully compile. I am having a problem with the DatabaseHelper class. Specifically the getDao() method:
/**
* Returns the Database Access Object (DAO) for our SimpleData class.
* It will create it or return the cached value.
*/
public Dao<SimpleData, Integer> getDao() throws SQLException {
if (simpleDao == null) {
simpleDao = getDao(SimpleData.class);
}
return simpleDao;
}
Here is the compile time error I am receiving:
Type parameters of D cannot be determined; no unique maximal instance exists for type variable D with upper bounds com.j256.ormlite.dao.Dao,com.j256.ormlite.dao.Dao
I got a similar error when trying to build my ormlite project using Netbeans:
Compiling 15 source files to ~/NetBeansProjects/Main/build/classes
Main.java:74: type parameters of D cannot be determined;
no unique maximal instance exists for type variable D with upper bounds
com.j256.ormlite.dao.Dao,com.j256.ormlite.dao.Dao
pcDao = DaoManager.createDao(connectionSource, PC.class);
Due to the comments I switched my Java Platform from OpenJDK 1.6 to Oracle's JDK 1.7.0_02 and it resolved the issue.
My solution:
public class HelloAndroid extends OrmLiteBaseActivity<DatabaseHelper>
{
private final String LOG_TAG = getClass().getSimpleName();
/**
* Called when the activity is first created.
*/
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
Log.i(LOG_TAG, "creating " + getClass() + " at " + System.currentTimeMillis());
TextView tv = new TextView(this);
doSampleDatabaseStuff("onCreate", tv);
setContentView(tv);
}
/**
* Do our sample database stuff.
*/
private void doSampleDatabaseStuff(String action, TextView tv)
{
// get our dao
RuntimeExceptionDao<SimpleData, Integer> simpleDao = getHelper().getSimpleDataDao();
// query for all of the data objects in the database
List<SimpleData> list = simpleDao.queryForAll();
// our string builder for building the content-view
StringBuilder sb = new StringBuilder();
sb.append("got ").append(list.size()).append(" entries in ").append(action).append("\n");
// if we already have items in the database
int simpleC = 0;
for (SimpleData simple : list)
{
sb.append("------------------------------------------\n");
sb.append("[").append(simpleC).append("] = ").append(simple).append("\n");
simpleC++;
}
sb.append("------------------------------------------\n");
for (SimpleData simple : list)
{
simpleDao.delete(simple);
sb.append("deleted id ").append(simple.id).append("\n");
Log.i(LOG_TAG, "deleting simple(" + simple.id + ")");
simpleC++;
}
int createNum;
do
{
createNum = new Random().nextInt(3) + 1;
}
while (createNum == list.size());
for (int i = 0; i < createNum; i++)
{
// create a new simple object
long millis = System.currentTimeMillis();
SimpleData simple = new SimpleData(millis);
// store it in the database
simpleDao.create(simple);
Log.i(LOG_TAG, "created simple(" + millis + ")");
// output it
sb.append("------------------------------------------\n");
sb.append("created new entry #").append(i + 1).append(":\n");
sb.append(simple).append("\n");
try
{
Thread.sleep(5);
}
catch (InterruptedException e)
{
// ignore
}
}
tv.setText(sb.toString());
Log.i(LOG_TAG, "Done with page at " + System.currentTimeMillis());
}
}
I'm probably doing something wrong, but this is what happens:
I register a listener, wait for it to be called and when it executes and calls "Vector.clear()" it locks. The problem happens in the "pipeMsgEvent" method, here it is the, not so friendly-looking, code (if you want, go directly to "this is important" lines):
public class JxtaCustomer implements PipeMsgListener {
public static final int ANSWER_OK = 0;
public static final int ANSWER_TIMEOUT =-1;
public static final int ANSWER_NOT_ASKED =-2;
public static final int ANSWER_WORKING =-3;
public static final int REQ_SENT = 0;
public static final int REQ_INV_PIPE_ID =-1;
public static final int REQ_INV_PIPE_IO =-2;
public static final int REQ_INV_GROUP_ID =-3;
protected int answer;
protected JxtaGenericAdvertisement serviceAdv = null;
protected JxtaNode ThePeer = null;
JxtaBiDiPipe myBiDiPipe = null;
protected Vector<Entry> output = null;
public JxtaCustomer(JxtaGenericAdvertisement adv, JxtaNode peer)
{
ThePeer = peer;
serviceAdv = new JxtaGenericAdvertisement((Element)adv.getDocument(new MimeMediaType("text/xml")));
answer = ANSWER_NOT_ASKED;
Vector<Entry> output = new Vector<Entry>();
}
public void pipeMsgEvent(PipeMsgEvent event)
{
System.out.println("It Works! Uhuuu");
// We received a message
Message message = event.getMessage();
System.out.println("Lets GO! Uhuuu");
Message.ElementIterator elIt = message.getMessageElementsOfNamespace( serviceAdv.getName() );
System.out.println("A little bit more");
answer = ANSWER_WORKING;
System.out.println("enter");
// This is important: Here I get stuck, "clear"
// never appears on the screen
output.clear();
System.out.println("clear");
while (elIt.hasNext()) {
MessageElement mElem = elIt.next();
System.out.println(mElem.getElementName() + " " + mElem.toString());
output.add( new Entry( mElem.getElementName(), mElem.toString() ) );
}
System.out.println("leave");
answer = ANSWER_OK;
}
public int sendRequest(Vector<Entry> params)
{
try {
// Creating Pipe Advertisement
String pipeAdvType = PipeAdvertisement.getAdvertisementType();
PipeAdvertisement pipeAd = (PipeAdvertisement)AdvertisementFactory.newAdvertisement(pipeAdvType);
URI pipeURI = new URI(serviceAdv.getPipeID());
pipeAd.setPipeID( IDFactory.fromURI(pipeURI) );
pipeAd.setType(PipeService.UnicastType);
pipeAd.setName(serviceAdv.getName() + " Service Pipe");
pipeAd.setDescription("Created by " + serviceAdv.getName());
// Creating Group
JxtaGroup jxgp = ThePeer.getGroupFromID( serviceAdv.getGroupID() );
if (null == jxgp)
return REQ_INV_GROUP_ID;
PeerGroup group = jxgp.getPeerGroup();
if (null == group)
return REQ_INV_GROUP_ID;
// This is important: In the JxtaBiDiPipe call I register
// the callback, while I have access to the code, I think
// the problem is in my code
myBiDiPipe = new JxtaBiDiPipe( group, pipeAd, 30000, this);
if (myBiDiPipe.isBound()) {
Thread.sleep(500);
Message myMessage = new Message();
if (0 == params.size())
params.add( new Entry("dummy", "null") );
for (int i=0; i<params.size(); i++) {
String Key = params.get(i).getKey();
String Value = params.get(i).getValue();
StringMessageElement strMsgElem = new StringMessageElement( Key, Value, null);
myMessage.addMessageElement( serviceAdv.getName(), strMsgElem);
}
myBiDiPipe.sendMessage(myMessage);
answer = ANSWER_TIMEOUT;
return REQ_SENT;
}
} catch (URISyntaxException e){
e.printStackTrace();
return REQ_INV_PIPE_ID;
} catch (IOException e) {
return REQ_INV_PIPE_IO;
} catch (Exception e) {
e.printStackTrace();
}
return REQ_INV_PIPE_IO;
}
public Vector<Entry> getResponse()
{
Vector<Entry> results = new Vector<Entry>();
if (ANSWER_OK != answer)
return results;
// This is important: I always call "getState()" and check its value
// before calling this method, so you can say it's guaranteed to be
// called after answer = ANSWER_OK, which never happens because of the
// lock
for (int i=0; i<output.size(); i++)
results.add( output.get(i) );
return results;
}
public int getState()
{
int count = 10;
return answer;
}
}
I always create JxtaCustomer like this:
JxtaCustomer customer = new JxtaCustomer(adv, ThePeer);
Vector<Entry> params = new Vector<Entry>();
params.add( new Entry("key1", "value1") );
params.add( new Entry("key2", "value2") );
customer.sendRequest(params);
while(JxtaCustomer.ANSWER_OK != customer.getState()) {
// I was actually using synchronized locks and timed waits
// but since I'm stuck there I'm using this nonsense instead
}
Vector<Entry> response = customer.getResponse();
Here is where in the code I call "sleep", "wait" or I create a "synchronized" (this last one is never)
$ grep synchronized $(find . -name "*.java")
$ grep sleep $(find . -name "*.java")
./Src/net/ubi/jxta/JxtaCustomer.java: Thread.sleep(500);
$ grep wait $(find . -name "*.java")
./App/ExampleServices/SimpleSigner.java: boolean waiting = false;
./App/ExampleServices/SimpleSigner.java: waiting = true;
./App/ExampleServices/SimpleSigner.java: return (waiting && JxtaCustomer.ANSWER_OK == customer.getState());
./App/ExampleServices/SimpleSigner.java: if (!waiting)
./App/ExampleServices/SimpleSigner.java: waiting = false;
./App/ExampleServices/SimpleSigner.java: return "Error: Response not ready, wait more time\n";
Your constructor sets a local variable called output,and not the member variable, you have
Vector<Entry> output = new Vector<Entry>();
when it should be
output = new Vector<Entry>();
So, later on when you call output.clear() you're getting an Null Pointer Exception thrown, which is why the following lines of code don't get executed.
compiler warnings like "unused local variables" can help spot these sorts of mistakes.