当我运行代码时，我得到一个错误。奇怪的是，当我更改files.getTimeScore();为时files.getLineScore();，它执行时没有错误。但是，这些功能几乎彼此相同。
当我getTimeScore()从类中的 main 运行该方法时FileIO，它可以正常工作。
错误
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at tetris.FileIO.loadHighscores(FileIO.java:52)
at tetris.FileIO.getTimeScores(FileIO.java:31)
at tetris.HighScores.<init>(HighScores.java:39)
at tetris.Menu$2.actionPerformed(Menu.java:74)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:723)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:682)
at java.awt.EventQueue$3.run(EventQueue.java:680)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:696)
at java.awt.EventQueue$4.run(EventQueue.java:694)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:693)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)
代码
高分班public HighScores(){
// init A
super("Highscores");
c=getContentPane();
test = new String[100][2];
files = new FileIO();
mainPanel = new JPanel();
test = files.getTimeScores();
timeTable = new JTable(test,timeTitles );
test = files.getLineScores();
lineTable = new JTable(test,lineTitles );
import java.io.File;
import java.io.InputStream;
import java.io.Writer;
import java.util.Scanner;
public class FileIO {
private File file;
private Scanner filescScanner, lineScanner;
private Writer fileWriter, lineWriter;
private String[][] data;
public FileIO () {
data = new String[100][2];
}
public String[][] getLineScores(){
return this.loadHighscores(this.getClass().getResourceAsStream("LineHighscores.txt"));
}
public String[][] getTimeScores(){
return this.loadHighscores(this.getClass().getResourceAsStream("TimeHighscores.txt"));
}
public String[][] loadHighscores( InputStream resourceStream){
int x=0;
String test = "";
filescScanner = new Scanner(resourceStream);
while(filescScanner.hasNextLine()&& x<100) {
lineScanner = new Scanner(filescScanner.nextLine());
lineScanner.useDelimiter("-/-");
data[x][0]=lineScanner.next();//name
data[x][1]=lineScanner.next();//data
x++;
}
lineScanner.close();
filescScanner.close();
return data;
}