当我尝试在NetBeans中运行应用程序时，出现异常，提示Exception in Application start method
java.lang.reflect.InvocationTargetException
我知道这是一个在这里经常问到的问题，但似乎没有一个问题和答案有效。我尝试了其中的几个，例如，将fxml文件的目录从src/main/java/更改为src/main/resources。
这是我的主要课程代码：
package com.zarja.offlinestudio;
import com.zarja.offlinestudio.util.settings.SettingsUtil;
import com.zarja.offlinestudio.util.log.LogUtil;
import com.zarja.offlinestudio.view.util.SceneManager;
import javafx.application.Application;
import javafx.stage.Stage;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class OfflineStudioGUI extends Application {
private static final String CLASS_NAME = OfflineStudioGUI.class.getCanonicalName();
private static final Logger LOGGER = LoggerFactory.getLogger(CLASS_NAME);
@Override
public void start(Stage stage) throws Exception {
LogUtil.init();
SettingsUtil.init();
SceneManager.init(stage);
//UserManager.getInstance();
}
public static void main(String[] args) {
launch(args);
}
}
我的SettingsUtil类（这是发生异常的地方）
package com.zarja.offlinestudio.util.settings;
//import com.zarja.offlinestudio.util.oldCode.DataManager;
import com.zarja.offlinestudio.util.log.LogMessages;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Map;
import java.util.Properties;
import java.util.TreeMap;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
//import java.util.logging.Level;
//import java.util.logging.Logger;
public class SettingsUtil {
private static final String CLASS_NAME = SettingsUtil.class.getCanonicalName();
private static final Logger LOGGER = LoggerFactory.getLogger(CLASS_NAME);
private static final Properties SETTINGS = new Properties();
private static final String FILE_NAME = "settings.txt";
public static void init() { //loadSettings
try {
SETTINGS.load(new FileInputStream(FILE_NAME));
} catch (FileNotFoundException ex) {
resetToDefaultProperties();
//LOGGER.log(Level.INFO, "File {1} was not found, so one was created", FILE_NAME);
LOGGER.info(LogMessages.get(LogMessages.SETTINGS_UTIL.INFO.LOAD), FILE_NAME);
saveSettings();
} catch (IOException ex) {
//LOGGER.log(Level.SEVERE, "Problem with file input stream", ex);
LOGGER.error(LogMessages.get(LogMessages.SETTINGS_UTIL.SEVERE.LOAD), ex);
}
}
public static void saveSettings() {
try {
SETTINGS.store(new FileOutputStream(FILE_NAME), CLASS_NAME);
} catch (FileNotFoundException ex) {
//LOGGER.log(Level.SEVERE, "File not found", ex);
LOGGER.error(LogMessages.get(LogMessages.SETTINGS_UTIL.SEVERE.SAVE_FNF), ex);
} catch (IOException ex) {
//LOGGER.log(Level.SEVERE, "Problem with file output stream", ex);
LOGGER.error(LogMessages.get(LogMessages.SETTINGS_UTIL.SEVERE.SAVE_OS), ex);
}
}
public static void resetToDefaultProperties() {
setMap(App.getDefaultConfig());
}
public static Map<String, String> getMap() {
TreeMap<String, String> treeMap = new TreeMap<>();
for(final String key: SETTINGS.stringPropertyNames()) {
treeMap.put(key, SETTINGS.getProperty(key));
}
return treeMap;
}
public static void setMap(Map<String, String> map) {
SETTINGS.clear();
SETTINGS.putAll(map);
}
public static String get(String propertyName) {
return SETTINGS.getProperty(propertyName);
}
public static void set(String propertyName, String propertyValue) {
SETTINGS.setProperty(propertyName, propertyValue);
}
}
StackTrace：
Exception in Application start method
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$154(LauncherImpl.java:182)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException
at java.util.Hashtable.put(Hashtable.java:460)
at java.util.Hashtable.putAll(Hashtable.java:524)
at com.zarja.offlinestudio.util.settings.SettingsUtil.setMap(SettingsUtil.java:64)
at com.zarja.offlinestudio.util.settings.SettingsUtil.resetToDefaultProperties(SettingsUtil.java:51)
at com.zarja.offlinestudio.util.settings.SettingsUtil.init(SettingsUtil.java:28)
at com.zarja.offlinestudio.OfflineStudioGUI.start(OfflineStudioGUI.java:19)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$161(LauncherImpl.java:863)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$174(PlatformImpl.java:326)
at com.sun.javafx.application.PlatformImpl.lambda$null$172(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$173(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$147(WinApplication.java:177)
... 1 more
Exception running application com.zarja.offlinestudio.OfflineStudioGUI
我仔细查看了堆栈跟踪，但是我无法弄清问题所在。