我使用 ACM图形库创建了Atari Breakout游戏的克隆版本,并刚刚添加了高分界面和功能。玩家的姓名和分数应显示在GUI窗口上(成功显示),并且还应写入.dat
二进制文件中。
但是,当代码尝试加载现有文件时,出现以下错误。
writing aborted; java.io.NotSerializableException: acm.graphics.GCanvasListener
我已经在线研究了此错误,看来可以通过编辑该类以实现Serializable
来解决。但是,引发此错误的类不是我自己的,而是属于第三方ACM图形库的类。我该如何解决?
我什至不确定为什么首先要导致此错误,因为我尝试序列化的数据只是名称和得分,我不是在尝试序列化物体或类似物体的画布。
主类(称为Breakout)
public class Breakout extends GraphicsProgram {
... // game variables
public void run() {
... // this if clause runs when game ends
if (brickCounter > 0) {
removeAll(); // clears screen
printGameOver(); // displays game over message
HighscoreManager hm = new HighscoreManager();
String name = getHighScoreName();
hm.addScore(name, score);
hm.displayHighscores();
}
}
... // game functionality methods
private String getHighScoreName(){
IODialog dialog = new IODialog();
String name = dialog.readLine("Enter your name: ");
return name;
}
得分班
private class Score implements Serializable {
private int score;
private String name;
public Score(String name, int score) {
this.score = score;
this.name = name;
}
public int getScore() { return score; }
public String getName() { return name; }
}
ScoreComparator类
private class ScoreComparator implements Comparator<Score> {
public int compare(Score score1, Score score2) {
int sc1 = score1.getScore();
int sc2 = score2.getScore();
if (sc1 > sc2) {
return -1;
} else if (sc1 < sc2) {
return 1;
} else {
return 0;
}
}
}
HighscoreManager类
private class HighscoreManager {
private ArrayList<Score> scores;
private static final String HIGHSCORE_FILE = ".//bin//scores.dat";
ObjectOutputStream outputStream = null;
ObjectInputStream inputStream = null;
public HighscoreManager() {
scores = new ArrayList<Score>(10);
}
public ArrayList<Score> getScores() {
loadScoreFile();
sort();
return scores;
}
private void sort() {
ScoreComparator comparator = new ScoreComparator();
Collections.sort(scores, comparator);
}
public void addScore(String name, int score) {
loadScoreFile();
scores.add(new Score(name, score));
updateScoreFile();
}
public void loadScoreFile() {
try {
inputStream = new ObjectInputStream(new FileInputStream(HIGHSCORE_FILE));
scores = (ArrayList<Score>) inputStream.readObject();
}
catch (FileNotFoundException e) {
System.out.println("[Load] File Not Found Error: " + e.getMessage());
}
catch (IOException e) {
System.out.println("[Load] Input/Output Error: " + e.getMessage());
}
catch (ClassNotFoundException e) {
throw new RuntimeException("[Load] Class Not Found Error: " + e.getMessage());
}
finally {
try {
if (outputStream != null) {
outputStream.flush();
outputStream.close();
}
} catch (IOException e) {
System.out.println("[Load] Input/Output Error: " + e.getMessage());
}
}
}
public void updateScoreFile() {
try {
outputStream = new ObjectOutputStream(new FileOutputStream(HIGHSCORE_FILE));
outputStream.writeObject(scores);
}
catch (FileNotFoundException e) {
System.out.println("[Update] File Not Found Error: " + e.getMessage());
}
catch (IOException e) {
System.out.println("[Update] Input/Output Error: " + e.getMessage());
}
finally {
try {
if (outputStream != null) {
outputStream.flush();
outputStream.close();
}
} catch (IOException e) {
System.out.println("[Update] Input/Output Error: " + e.getMessage());
}
}
}
public void displayHighscores() {
int max = 10;
ArrayList<Score> scores;
scores = getScores();
int x = scores.size();
if (x > max) {
x = max;
}
removeAll(); // clears screen
int npos = 160;
int spos = 160;
for (int i = 0; i < x; i++) {
GLabel showName = new GLabel(scores.get(i).getName(), (getWidth() / 2.0) - 100, (getHeight() / 2.0) - npos);
showName.move(-showName.getWidth() / 2, -showName.getHeight());
showName.setColor(Color.WHITE);
add(showName);
npos -= 40;
}
for (int i = 0; i < x; i++) {
GLabel showScore = new GLabel(Integer.toString(scores.get(i).getScore()), (getWidth() / 2.0) + 100, (getHeight() / 2.0) - spos);
showScore.move(-showScore.getWidth() / 2, -showScore.getHeight());
showScore.setColor(Color.WHITE);
add(showScore);
spos -= 40;
}
}
运行应用程序后:
[Load] Input/Output Error: writing aborted; java.io.NotSerializableException: acm.graphics.GCanvasListener
[Update] Input/Output Error: acm.graphics.GCanvasListener
[Load] Input/Output Error: writing aborted; java.io.NotSerializableException: acm.graphics.GCanvasListener
答案 0 :(得分:0)
您应该进入名称和得分字段所在的班级,并添加例如public class nameclass implements Serializable
。我希望它对您有用。
答案 1 :(得分:0)
您的任务将是从您的姓名和分数结构中找到UI组件的隐藏引用。许多GUI应用程序使用许多内部类,这可能是缺少的链接。
当你上课时,像这样:
class MyGame {
private SomeUIWidget widget;
class TopScore implements Serializable {
String name;
int score;
...
}
...
}
TopScore
中有一个隐藏的成员,它引用MyGame
的“封闭实例”,包括其SomeUIWidget
成员。当您尝试序列化TopScore
实例时,其余所有实例都将被拖入其中。
您可以简单地将TopScore
声明为static
嵌套类。这意味着没有封闭的实例,仅用于从其他代码隐藏TopScore
类。但是,我建议仅在自己的文件中将TopScore
设为一个顶级类,因为其他对象很可能希望以不同的方式使用这些对象,也就是说,似乎很可能成为该对象的候选对象您的公共API。
这是有根据的猜测,没有任何实际的代码。为了获得更好的答案,请将代码减少到演示问题所需的最低限度,并将其包含在问题中。