I am trying to make an exception where an error message pops up saying
Error: Amount is required
when they haven't added the amount in the box. Here is what I have:
String output = "Gas Amount: $" + gasAmount +
"\nCar Wash: " + price;
try {
throw new AmountException();
JOptionPane.showMessageDialog(null, output);
}
catch (AmountException ae) {
JOptionPane.showMessageDialog(null, ae.toString(), "Error", JOptionPane.ERROR_MESSAGE);
}
}
Something like this:
public class AmountException extends Throwable
{
public AmountException()
{
super("Error: Amount is required!!");
}
}
In your code:
try
{
if (gasAmount == null)
throw new AmountException();
JOptionPane.showMessageDialog(null, output);
}
catch (AmountException ae)
{
JOptionPane.showMessageDialog(null, ae.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
}
Related
I have confusing (lack of comprehension) trying to translate some part of my code to Optional on Java 8.
First example mock Code
private void privateMethodOne(CustomRequesDto customRequesDto) {
// Some lines of code
ResponseEntity<CustomResponseDto> responseEntity;
try {
responseEntity = callWebClientRequestOne();
} catch (Exception e) {
RuntimeException ex = new CustomClientException(customRequesDto, e.getMessage());
log.error(ex.getMessage());
throw ex;
}
if (responseEntity.getBody() == null) {
throw new CustomResponseException("myMessage");
}
CustomResponseDto customResponseDto = responseEntity.getBody();
return Optional.ofNullable(customResponseDto).map(CustomResponseDto::getProperty).orElse(null);
}
In the First example mock Code, I would like to reduce this lines in a single line, using Optional (if it is possible)
if (responseEntity.getBody() == null) {
throw new CustomResponseException("myMessage");
}
CustomResponseDto customResponseDto = responseEntity.getBody();
return Optional.ofNullable(customResponseDto).map(CustomResponseDto::getProperty).orElse(null);
How to do the same in a Single line?
Second example mock Code
private void privateMethodTwo(CustomRequesDto customRequesDto) {
// Some lines of code
ResponseEntity<byte[]> responseEntity = null;
try {
responseEntity = callWebClientRequestTwo();
} catch (Exception e) {
mapExceptions.put(customRequesDto, e.getMessage());
}
try {
if (responseEntity != null && responseEntity.getBody() == null) {
throw new CustomResponseException("myMessage");
}
} catch (Exception e) {
mapExceptions.put(someObject, e.getMessage());
}
// continue the executions
}
Second example mock Code, I would like to reduce this lines in a single line, using Optional (if it is possible)
try {
if (responseEntity != null && responseEntity.getBody() == null) {
throw new CustomResponseException("myMessage");
}
} catch (Exception e) {
mapExceptions.put(someObject, e.getMessage());
}
How to perform the same in a Single line?
I'm new to the quarkus framework where I'm writing rabbitmq-client library based on quarkur framework. I'm using io.quarkiverse.rabbitmqclient.RabbitMQClient.
I need to write JUnit for basic send and consume operations, please help me with how can I write junit and mock RabbitMQClient. I'm using the below code to send and consume message.
#ApplicationScoped
public class RabbitMQProducerAdapterImpl extends RabbitMQCongiguration implements RabbitMQProducerAdapter {
#Override
public void sendMessage(String exchange, String routingKey, String messagePayload) throws IOException {
setUpConnectionAndChannel();
channel.basicPublish(exchange, routingKey, null, messagePayload.getBytes(StandardCharsets.UTF_8));
Log.info("message sent succefully: " + messagePayload);
}
}
Here is the RabbitMQCongiguration
#ApplicationScoped
public class RabbitMQCongiguration {
#Inject
private RabbitMQClient rabbitClient;
protected Channel channel;
protected void setUpConnectionAndChannel() {
try {
// create a connection
Connection connection = rabbitClient.connect();
// create a channel
channel = connection.createChannel();
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
protected void setupQueueInDirectExchange(String exchangeName, String routingKey, String queueName,
boolean createExchangeQueues) throws IOException {
setUpConnectionAndChannel();
if (createExchangeQueues) {
this.channel.exchangeDeclare(exchangeName, BuiltinExchangeType.DIRECT, true, false, false, null);
// declaring a queue for this channel. If queue does not exist,
// it will be created on the server. this line not needed if queue already
// present
this.channel.queueDeclare(queueName, true, false, false, null);
}
// Bind Routing Key to Exchange
this.channel.queueBind(queueName, exchangeName, routingKey);
}
}
Below is the class for consumer
#ApplicationScoped
public class RabbitMQConsumerAdapterImpl extends RabbitMQCongiguration implements RabbitMQConsumerAdapter, Runnable {
private String queueName;
private MessageProcessor messageProcessor;
#Override
public void consumeMessage(String exchange, String queueName, String routingKey,
MessageProcessor messageProcessor) throws IOException {
Log.info("starting consumer...");
try {
this.queueName = queueName;
this.messageProcessor = messageProcessor;
Log.info("setting up rabbitMQPrefetchCountConfig");
setupQueueInDirectExchange(exchange, routingKey, queueName, false);
Thread consumerThread = new Thread(this);
consumerThread.start();
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
#Override
public void run() {
try {
// start consuming messages. Auto acknowledge messages.
Log.info("Start consuming messages from thread...");
channel.basicConsume(this.queueName, false, (Consumer) new DefaultConsumer(channel) {
#Override
public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties,
byte[] body) throws IOException {
String msgPayload = null;
if (body == null || body.length == 0) {
Log.warn("Invalid Message Body - Consumer Tag : " + consumerTag + ", Message DeliveryTag : "
+ envelope.getDeliveryTag());
channel.basicReject(envelope.getDeliveryTag(), false);
} else {
msgPayload = new String(body);
try {
JsonParser.parseString(msgPayload);
} catch (JsonSyntaxException ex) {
Log.error(msgPayload + " is not a valid json, Reason - ", ex);
channel.basicReject(envelope.getDeliveryTag(), false);
Log.warn("Rejected the current payload.");
return;
}
messageProcessor.processMessage(msgPayload);
channel.basicAck(envelope.getDeliveryTag(), false);
}
// just print the received message.
Log.info("Received: " + new String(body, StandardCharsets.UTF_8));
}
});
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
#ApplicationScoped
public class MessageProcessorImpl implements MessageProcessor{
#Override
public void processMessage(String messagePayload) {
Log.info("message consumed: " + messagePayload);
}
}
I want to to print my row red when book is out of stock but i am getting error like that every time i try new idea to manage that:
"com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException:
Data source rejected establishment of connection, message from
server: "Too many connections"
Even if i try to close all connections in same loop...
So here we go:
private boolean checkIfOutOfStock(BookDetail book) throws SQLException{
String query = "select * from tbl_loan where book_id = " + book.getId() + " ";
dc = new DbConnection();
conn = dc.connect();
PreparedStatement checkPst = conn.prepareStatement(query);
ResultSet checkRs = checkPst.executeQuery(query);
if(checkRs.next()){
checkRs.close();
checkPst.close();
return true;
} else
{
checkRs.close();
checkPst.close();
return false;
}
}
#Override
public void initialize(URL location, ResourceBundle resources) {
dc = new DbConnection();
conn = dc.connect();
selectionModel = editTabPane.getSelectionModel();
editTableBooks.setRowFactory(tv -> new TableRow<BookDetail>() {
#Override
public void updateItem(BookDetail item, boolean empty) {
super.updateItem(item, empty) ;
if (item == null) {
setStyle("");
} else
try {
if (checkIfOutOfStock(item)) {
setStyle("-fx-background-color: tomato;");
} else {
setStyle("");
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
It works fine until i slide up and down table few times... its like everytime i slide table im opening new connection. Any idea how to solve it?
Hey do you mean something like that?
editTableBooks.setRowFactory(tv -> new TableRow<BookDetail>() {
#Override
public void updateItem(BookDetail item, boolean empty) {
super.updateItem(item, empty) ;
Platform.runLater(new Runnable() {
#Override
public void run() {
if (item == null) {
setStyle("");
} else
try {
if (checkIfOutOfStock(item)) {
setStyle("-fx-background-color: tomato;");
} else {
setStyle("");
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
});
It doesn't change anything or i just didn't get it :P
I would like to run a task during the waiting of a web request. If the task finishes before the request can return a response, then I would display a message "The server is taking too long". I'm using a WebClient object, how can I manage the time out?
public Class Result
{
protected override void OnNavigatedTo(NavigationEventArgs e)
{
if (NavigationContext.QueryString.TryGetValue("critere", out sCritere))
{
try
{
_datamanager = new DataManager();
_datamanager.m_evt_Client_DownloadStringCompleted += OnDownloadStringCompleted;
_datamanager.DownloadXmlData(DataManager.URL_RECHERCHE, sCritere);
//HERE I NEED TO RUN A TIMER If the response is too long i would display a message
}
catch(Exception ex)
{
MessageBox.Show(ex.Message, "Erreur", MessageBoxButton.OK);
NavigationService.GoBack();
NavigationService.RemoveBackEntry();
}
}
}
}
public Class DataManager
{
public void DownloadXmlData(string uri, string critere = "")
{
try
{
WebClient client = new WebClient();
client.DownloadStringCompleted += new DownloadStringCompletedEventHandler(client_DownloadStringCompleted);
client.Credentials = new NetworkCredential(UserSaved, PasswordSaved, domain);
client.DownloadStringAsync(new Uri(uri + critere));
}
catch(WebException )
{
throw new WebException(MyExceptionsMessages.Webexception) ;
}
catch (Exception )
{
throw new UnknowException(MyExceptionsMessages.UnknownError);
}
}
public void client_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
//raise Downloadstringcompleted event if error==null
}
}
You can use BackgroundWorker..
BackgroundWorker bw = new BackgroundWorker();
bw.DoWork += (s, e) =>
{
// your task to do while webclient is downloading
};
bw.RunWorkerCompleted += (s, e) =>
{
// check whether DownloadStringCompleted is fired or not
// if not, cancel the WebClient's asynchronous call and show your message.
client.CancelAsync();
MessageBox.Show("message");
}
client.DownloadStringAsync(uri);
bw.RunWorkerAsync();
I'm working on parsing JSON on BlackBerry using org.json.me, but I can't parsing the result. Simulator Console says: No Stack Trace
Here's my code to parsing JSON after receiving JSON string from my restclient
try {
JSONObject outer=new JSONObject(data);
JSONArray ja = outer.getJSONArray("status");
JSONArray arr=ja.getJSONArray(0);
System.out.println(arr);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
And here's the piece code to get JSON from the server
public PromoThread(final String url, final ResponseCallback callback){
Thread t = new Thread(new Runnable(){
public void run() {
waitScreen = new WaitPopupScreen();
System.out.println("Log >> Promo thread run...");
synchronized (UiApplication.getEventLock()){
UiApplication.getUiApplication().pushScreen(waitScreen);
}
//network call
try {
conn = (HttpConnection) new ConnectionFactory().getConnection(url).getConnection();
conn.setRequestMethod(HttpConnection.GET);
conn.setRequestProperty("User-Agent", "Profile/MIDP-1.0 Confirguration/CLDC-1.0");
if (conn.getResponseCode() == HttpConnection.HTTP_OK) {
in = conn.openInputStream();
// parser.parse(in, handler);
//buff.append(IOUtilities.streamToBytes(in));
//result = buff.toString();
results = new String(IOUtilities.streamToBytes(in));
//System.out.println("Log >> Result: " + results);
UiApplication.getUiApplication().invokeLater(
new Runnable() {
public void run() {
//UiApplication.getUiApplication().popScreen(waitScreen);
callback.callback(results, waitScreen);
}
});
}
} catch (Exception ex) {
ex.printStackTrace();
} finally {
try {
if (in != null) {
in.close();
}
conn.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
});
//start thread
t.start();
}
Thanks for your help