I have a problem, when I try to set the text of my JLabel it only changes after the code ends...
Here's my code:
public static void start(String username, String aToken, String uuid) {
SUpdate su = new SUpdate(...));
// Some parameters here...
LauncherPanel.title.setText("Mise à jour du jeu...");
try {
su.start();
} catch (BadServerResponseException e) {
e.printStackTrace();
} catch (ServerDisabledException e) {
e.printStackTrace();
} catch (BadServerVersionException e) {
e.printStackTrace();
} catch (ServerMissingSomethingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
If you need more infos, just ask me
You need to call the repaint() method of your JLabel, like LauncherPanel.title.repaint().
Related
I have this method sendParameterValueAsMQTTMessage() which I use to publish message via MQTT on a specific topic. I am using try catch two times after another (not nested) but it still seems somewhat ugly and overcrowding the method. I read an article on clean code where Uncle Bob talks about extracting the body of try catch but I seem to not grasp it quite well or at least not in my case.
How could I get rid of the try catch in my method by extracting it outside?
public void sendParameterValueAsMQTTMessage() {
String payload = null;
try {
payload = convertToJSONString("range", String.valueOf(range));
} catch (JSONException e) {
this.logger.log(Level.ERROR, e);
}
MQTTMessage message = new MQTTMessage(MQTTTopics.RANGE_TOPIC,payload,0);
try {
this.client.publish(message);
Thread.sleep(3000);
} catch (Exception e) {
this.logger.log(Level.ERROR, e);
}
}
there are multiple different problems with provided code, here is how I'd refactor it:
public void sendParameterValueAsMQTTMessage() {
final String payload = tryGetPayloadAsJson();
if (payload != null) {
trySendPayloadViaMQTT(payload);
}
}
private String tryGetPayloadAsJson() {
try {
return convertToJSONString("range", String.valueOf(range));
} catch (JSONException e) {
this.logger.log(Level.ERROR, e);
}
return null;
}
private void trySendPayloadViaMQTT(final String payload) {
try {
final MQTTMessage message = new MQTTMessage(MQTTTopics.RANGE_TOPIC, payload, 0);
this.client.publish(message);
Thread.sleep(3000);
} catch (Exception e) {
this.logger.log(Level.ERROR, e);
}
}
one thing which might be improved here based on Uncle Bob's advice is to actually move try/catch outside of trySendPayloadViaMQTT, like this:
public void sendParameterValueAsMQTTMessage() {
final String payload = tryGetPayloadAsJson();
if (payload != null) {
trySendPayloadViaMQTT(payload);
}
}
private String tryGetPayloadAsJson() {
try {
return convertToJSONString("range", String.valueOf(range));
} catch (JSONException e) {
this.logger.log(Level.ERROR, e);
}
return null;
}
private void trySendPayloadViaMQTT(final String payload) {
try {
sendPayloadViaMQTT(payload);
} catch (Exception e) {
this.logger.log(Level.ERROR, e);
}
}
private void sendPayloadViaMQTT(final String payload) {
final MQTTMessage message = new MQTTMessage(MQTTTopics.RANGE_TOPIC, payload, 0);
this.client.publish(message);
Thread.sleep(3000);
}
you can put all of your code in just one try block and set multiple catches, when ever an exception be happened, the catch that is revelated to it will be execute, like:
try{
int a[]=new int[5];
a[5]=30/0;
}
catch(ArithmeticException e)
{
System.out.println("Arithmetic Exception occurs");
}
catch(ArrayIndexOutOfBoundsException e)
{
System.out.println("ArrayIndexOutOfBounds Exception occurs");
}
You can use single general catch for both possible exceptions inside the method as following:
public void sendParameterValueAsMQTTMessage() {
String payload = null;
try {
payload = convertToJSONString("range", String.valueOf(range));
MQTTMessage message = new MQTTMessage(MQTTTopics.RANGE_TOPIC,payload,0);
this.client.publish(message);
Thread.sleep(3000);
} catch (Exception e) {
this.logger.log(Level.ERROR, e);
}
}
public void sendParameterValueAsMQTTMessage() {
String payload = null;
try {
payload = convertToJSONString("range", String.valueOf(range));
} catch (JSONException e) {
this.logger.log(Level.ERROR, e);
}
MQTTMessage message = new MQTTMessage(MQTTTopics.RANGE_TOPIC,payload,0);
publishMessage(message); //extracted in a new method
}
public void publishMessage(MQTTMessage message){
try {
this.client.publish(message);
Thread.sleep(3000);
} catch (Exception e) {
this.logger.log(Level.ERROR, e);
}
}
I have an app with 2 tabs where the first include somes values which are refreshed during the time. I take these values from a PhoneStateListener activity and I transfer them into the fragment with the function below. The problem is, when I move to 2nd tab and after that move back to first the values are not refresed anymore.
public void test(int LteSignalStrength,int LteRsrp,int LteRsrq,int LteRssnr,int LteCqi){
if(ntype=="\nNetwork Type: LTE\n"){
tv2.setText("\nLteSignalStrength:"+dbm+" dbm"+
"\nLteRsrp: "+LteRsrp+
"\nLteRsrq: "+LteRsrq+
"\nLteRssnr: "+LteRssnr);
}
}
PhonestateListener Activity
public Tab1Signal(Tab1Values fragment){
mcontext = fragment.getContext();
main=fragment;
}
public void onSignalStrengthsChanged(SignalStrength signalStrength){
super.onSignalStrengthsChanged(signalStrength);
try {
Method[] methods = android.telephony.SignalStrength.class.getMethods();
for (Method mthd : methods) {
if (mthd.getName().equals("getLteSignalStrength")){
//val1=mthd.getName() ;
LteSignalStrength=(Integer)mthd.invoke(signalStrength);
//main.test(val2);
}
if (mthd.getName().equals("getLteRsrp")){
LteRsrp=(Integer)mthd.invoke(signalStrength);
}
if (mthd.getName().equals("getLteRsrq")){
LteRsrq=(Integer)mthd.invoke(signalStrength);
}
if (mthd.getName().equals("getLteRssnr")){
LteRssnr=(Integer)mthd.invoke(signalStrength);
}
if (mthd.getName().equals("getLteCqi")){
LteCqi=(Integer)mthd.invoke(signalStrength);
}
main.test(LteSignalStrength,LteRsrp,LteRsrq,LteRssnr,LteCqi);
}
} catch (SecurityException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
Does anyone know how can I solve it?
You can pass listener in method onTabChanged when tab contain Tab1Signal
i am trying to generate a snapshot from a video using the following code. and it is working fine running as a java application on sts.
public class VideoThumbTaker {
public static void main(String[] args)
{
FFmpegFrameGrabber g = new FFmpegFrameGrabber("/home/anupam/Downloads/jk.mp4");
g.setFormat("mp4");
try {
g.start();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
for (int i = 0 ; i < 1 ; i++) {
try {
ImageIO.write(g.grab().getBufferedImage(), "png", new File("/home/anupam/Downloads/" + System.currentTimeMillis() + ".png"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
try {
g.stop();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
using maven dependency
<dependency>
<groupId>org.bytedeco</groupId>
<artifactId>javacv</artifactId>
<version>0.8</version>
</dependency>
after deploying a war file.the following code gives Error loading class org/bytedeco/javacpp/Loader
#RequestMapping(value = "menu9data", method = RequestMethod.POST)
public JSONObject view(#RequestPart(name = "file", required = false) MultipartFile image,#Valid MenuData model, BindingResult results) {
String name1;
FFmpegFrameGrabber g = new FFmpegFrameGrabber("/home/anupam/Downloads/"+name1); //Error
g.setFormat("mp4");
try {
System.out.println("enterss");
g.start();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
for (int i = 0 ; i < 1 ; i++) {
/* try {
// ImageIO.write(((Object) g.grab()).getBufferedImage(), "png", new File("/home/anupam/Downloads/"+name1+"snap"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}*/
}
try {
g.stop();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
I'm trying to consolidate 2 methods into 1, because they handle exceptions the same way. I know in C# you can pass functions/actions as parameters into other functions. I tried creating a generic method to invoke a function, but can't seem to figure it out.
public String getTheStuff(String client) {
try {
return extService.getProduct(client);
} catch (UIException e) {
notHealthy();
} catch (HostException e) {
notHealthy();
} catch (Exception e) {
Throwables.propagate(e);
}
}
public CustomType getsomeMoreStuff(String source, int offset) {
try {
return extService.getMetrics(source, offset);
} catch (UIException e) {
notHealthy();
} catch (HostException e) {
notHealthy();
} catch (Exception e) {
Throwables.propagate(e);
}
}
What I'm looking for is something like
public T invokeExtService(Function functionToInvoke, Parameters[] params){
try {
return functionToInvoke.Invoke(params);
} catch (UIException e) {
notHealthy();
} catch (HostException e) {
notHealthy();
} catch (Exception e) {
Throwables.propagate(e);
}
}
As #LouisWasserman said, this would be much nicer in Java 8, but how about something like this (untested):
public <T> T invoke(Callable<T> function) {
try {
return function.call();
} catch (UIException e) {
notHealthy();
} catch (HostException e) {
notHealthy();
} catch (Exception e) {
Throwables.propagate(e);
}
}
public String getTheStuff(final String client) {
return invoke(new Callable<String>() {
#Override
public String call() {
return extService.getProduct(client);
}
});
}
public CustomType getsomeMoreStuff(final String source, final int offset) {
return invoke(new Callable<CustomType>() {
#Override
public CustomType call() {
return extService.getMetrics(source, offset);
}
});
}
To be honest, I'm not sure how worthwhile this is considering how short your methods are (and they could be even shorter with multi-catch).
I have the following:
public void method(){
try {
methodThrowingIllegalArgumentException();
return;
} catch (IllegalArgumentException e) {
anotherMethodThrowingIllegalArgumentException();
return;
} catch (IllegalArgumentException eee){ //1
//do some
return;
} catch (SomeAnotherException ee) {
return;
}
}
Java does not allow us to catch the exception twice, so we got compile-rime error at //1. But I need to do exactly what I try to do:
try the methodThrowingIllegalArgumentException() method first and if it fails with IAE, try anotherMethodThrowingIllegalArgumentException();, if it fails with IAE too, do some and return. If it fails with SomeAnotherException just return.
How can I do that?
If the anotherMethodThrowingIllegalArgumentException() call inside the catch block may throw an exception it should be caught there, not as part of the "top level" try statement:
public void method(){
try{
methodThrowingIllegalArgumentException();
return;
catch (IllegalArgumentException e) {
try {
anotherMethodThrowingIllegalArgumentException();
return;
} catch(IllegalArgumentException eee){
//do some
return;
}
} catch (SomeAnotherException ee){
return;
}
}