我正在将新书插入我的书表中，并尝试将其分配给多对多关系表后。伊莫这应该在交易中运行。
（因为如果m2m插入失败，则会丢失有关房地产的信息）。现在，我的代码如下所示，由于由于静态上下文错误而无法访问public class Main {
private JFrame mainPane;
private RenderZone renderZone = new RenderZone();
private JScrollPane renderScrollPane = new JScrollPane(renderZone,
JScrollPane.VERTICAL_SCROLLBAR_NEVER,
JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Main window = new Main();
window.mainPane.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public Main() {
initialize();
}
private void initialize() {
mainPane = new JFrame();
mainPane.setPreferredSize(new Dimension(1024, 768));
mainPane.setSize(new Dimension(1024, 768));
mainPane.setLocation(new Point(200, 200));
mainPane.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
SpringLayout springLayout = new SpringLayout();
springLayout.putConstraint(SpringLayout.NORTH, renderScrollPane, 0, SpringLayout.NORTH, mainPane.getContentPane());
springLayout.putConstraint(SpringLayout.WEST, renderScrollPane, 0, SpringLayout.WEST, mainPane.getContentPane());
springLayout.putConstraint(SpringLayout.SOUTH, renderScrollPane, 0, SpringLayout.SOUTH, mainPane.getContentPane());
springLayout.putConstraint(SpringLayout.EAST, renderScrollPane, 0, SpringLayout.EAST, mainPane.getContentPane());
mainPane.getContentPane().setLayout(springLayout);
mainPane.getContentPane().add(renderScrollPane);
}
public class RenderZone extends JPanel {
private static final long serialVersionUID = -8240875812801921009L;
private BufferedImage image = null;
private BufferedImage sub = null;
public RenderZone() {
this.setBackground(Color.WHITE);
this.setPreferredSize(new Dimension(1124, 768));// added 100 for test purpose
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);// pour repeindre la panel à chaque fois
Graphics2D g2 = (Graphics2D)this.getGraphics();
if(image==null) {
try {
image = ImageIO.read(RenderZone.class.getResourceAsStream("TestImage0.png"));
sub = image.getSubimage(0, 0, 1024, 768);
} catch (IOException e) {}
}
if( sub!=null)g2.drawImage(sub, 0, 0, null);
g2.dispose();
}
}
}
查询，因此代码失败。
有一种简单的方法可以解决此问题吗？
BookUserXRefDao.insert(bookUser);答案 0 :(得分：0)
仅仅意识到我可以从我的交易中访问Singleton数据库实例。
因此，我可以使用
AppDb.getAppDb().BookUserXRefDao().insert(bookUser);
那解决了这个问题。