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对不起。我不会说英文很好，所以请理解我JavaFX空指针异常在label.setText（）
我正在为java制作smartmirror，但是我遇到了setText（）函数的问题。
在调用天气api并将位置名称保存到变量后，我启动label.setText（），但它有空指针异常。
我听说过platform.run later（）方法和任务，但它们不起作用。
请帮我TT 有我的源
package SmartMirror.main;
import java.io.IOException;
public class SpeechClass {
WeatherController weather = new WeatherController();
// Logger
private Logger logger = Logger.getLogger(getClass().getName());
// Variables
public String result;
// Threads
Thread speechThread;
Thread resourcesThread;
Thread openThread;
// LiveRecognizer
private LiveSpeechRecognizer recognizer;
protected String location;
public void Speech(){
// Loading Message
logger.log(Level.INFO, "Loading..\n");
// Configuration
Configuration configuration = new Configuration();
// Load model from the jar
configuration.setAcousticModelPath("resource:/edu/cmu/sphinx/models/en-us/en-us");
configuration.setDictionaryPath("resource:/edu/cmu/sphinx/models/en-us/cmudict-en-us.dict");
// if you want to use LanguageModelPath disable the 3 lines after which
// are setting a custom grammar->
// configuration.setLanguageModelPath("resource:/edu/cmu/sphinx/models/en-us/en-us.lm.bin")
// Grammar
configuration.setGrammarPath("resource:/grammars");
configuration.setGrammarName("grammar");
configuration.setUseGrammar(true);
try {
recognizer = new LiveSpeechRecognizer(configuration);
} catch (IOException ex) {
logger.log(Level.SEVERE, null, ex);
}
// Start recognition process pruning previously cached data.
recognizer.startRecognition(true);
// Start the Thread
startSpeechThread();
startResourcesThread();
}
/**
* Starting the main Thread of speech recognition
*/
protected void startSpeechThread() {
// alive?
if (speechThread != null && speechThread.isAlive())
return;
// initialise
speechThread = new Thread(() -> {
logger.log(Level.INFO, "You can start to speak...\n");
try {
while (true) {
/*
* This method will return when the end of speech is
* reached. Note that the end pointer will determine the end
* of speech.
*/
SpeechResult speechResult = recognizer.getResult();
if (speechResult != null) {
result = speechResult.getHypothesis();
System.out.println("You said: [" + result + "]\n");
if(result.equals("one")){
System.out.println("startOpenThread");
startWeatherThread();
openThread.sleep(3000);
Platform.runLater(new Runnable(){
@Override
public void run(){
weather.setLabel();
openweather();
}
});
}
// logger.log(Level.INFO, "You said: " + result + "\n")
} else
logger.log(Level.INFO, "I can't understand what you said.\n");
}
} catch (Exception ex) {
logger.log(Level.WARNING, null, ex);
}
logger.log(Level.INFO, "SpeechThread has exited...");
});
// Start
speechThread.start();
}
/**
* Starting a Thread that checks if the resources needed to the
* SpeechRecognition library are available
*/
protected void startResourcesThread() {
// alive?
if (resourcesThread != null && resourcesThread.isAlive())
return;
resourcesThread = new Thread(() -> {
try {
// Detect if the microphone is available
while (true) {
if (AudioSystem.isLineSupported(Port.Info.MICROPHONE)) {
// logger.log(Level.INFO, "Microphone is available.\n")
} else {
// logger.log(Level.INFO, "Microphone is not
// available.\n")
}
// Sleep some period
Thread.sleep(350);
}
} catch (InterruptedException ex) {
logger.log(Level.WARNING, null, ex);
resourcesThread.interrupt();
}
});
// Start
resourcesThread.start();
}
protected void startWeatherThread() {
try{
openThread = new Thread(() -> {
weather.Weather(); // 날씨를 변수에 저장
});
} catch (Exception e){
}
// Start
openThread.start();
}
public void openweather(){
Stage dialog = new Stage(StageStyle.TRANSPARENT);
dialog.initModality(Modality.WINDOW_MODAL);
dialog.initOwner(null);
Parent parent = null;
try {
parent = FXMLLoader.load(WeatherController.class.getResource("weather_scene.fxml"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Scene scene = new Scene(parent);
dialog.setScene(scene);
dialog.setResizable(false);
dialog.show();
}
}
package SmartMirror.Weather;
import java.io.BufferedReader;
public class WeatherController {
@FXML private Label labelLocation;
public String locationResult="", weatherResult="", tempResult="";
//날씨 API
public void Weather() {
try{
//OpenAPI call하는 URL
String urlstr = "http://api.openweathermap.org/data/2.5/weather?"
+"q=Chuncheon"
+"&appid=f1bccf50c733316db790a00a2d5165c6&units=metric";
URL url = new URL(urlstr);
BufferedReader bf;
String line;
String result="";
//날씨 정보를 받아온다.
bf = new BufferedReader(new InputStreamReader(url.openStream()));
//버퍼에 있는 정보를 문자열로 변환.
while((line=bf.readLine())!=null){
result=result.concat(line);
//System.out.println(line);
}
//문자열을 JSON으로 파싱
JSONParser jsonParser = new JSONParser();
JSONObject jsonObj = (JSONObject) jsonParser.parse(result);
//날씨 출력
JSONArray weatherArray = (JSONArray) jsonObj.get("weather");
JSONObject weather = (JSONObject) weatherArray.get(0);
//온도출력
JSONObject mainArray = (JSONObject) jsonObj.get("main");
double ktemp = Double.parseDouble(mainArray.get("temp").toString());
locationResult = (String) jsonObj.get("name");
weatherResult = (String) weather.get("main");
tempResult = Double.toString(ktemp) + "℃";
System.out.println("startWeatherThread" + locationResult);
bf.close();
}catch(Exception e){
System.out.println(e.getMessage());
}
}
public void setLabel(){
Platform.runLater(new Runnable(){
@Override
public void run(){
System.out.println(locationResult);
labelLocation.setText(locationResult);
}
});
}
}
您没有在控制器上调用'setLabel（）'：您正在调用它在不同的对象上（这恰好与控制器的类相同） 。很明显，注释了作为加载FXML文件一部分而创建的@ FXML的字段仅在实际控制器中初始化。 –