从 SQL 图像 binaryStream 的 InputStream 创建 ImageIcon 时出现 NullPointerException答案

【问题标题】：NullPointerException at create ImageIcon from InputStream of SQL image binaryStream从 SQL 图像 binaryStream 的 InputStream 创建 ImageIcon 时出现 NullPointerException
【发布时间】：2015-11-20 18:01:46
【问题描述】：

我正在构建一个显示来自 SQL Server 数据库的图像的应用程序，这里是代码：

这就是我从存储过程中获取 BinaryStream 的方式

public static ImageIcon getImageBytes(int id){
    InputStream is = null;
    ImageIcon img = null;
    try{

        String query = "exec [dbo].[sp_ObtenerImagen] '"+id+"'";
                     Statement state = Constant.Conecctions().createStatement();
                     ResultSet rs = state.executeQuery(query);
        while(rs.next()){
            is= rs.getBinaryStream(1);
        }  
    }catch(SQLException e){

    }
    try {
        img = new ImageIcon(ImageIO.read(is));
    } catch (IOException ex) {
        Logger.getLogger(D_Clientes.class.getName()).log(Level.SEVERE, null, ex);
    }
    return img;
}

因为我会将图像显示到 JPanel 中，所以我需要一个 Jlabel，所以我创建了这个：

public static JLabel bytesToIMG(int idCliente) {
        JLabel lab = new JLabel(D_Clientes.getImageBytes(idCliente));
        return lab;
}

所以，现在尝试向面板显示图像：

panelImagen.removeAll();
                panelImagen.add(OperacionImagen.bytesToIMG(Integer.parseInt(tableClientes.getModel().getValueAt(selectedRow, 0).toString())));
                panelImagen.revalidate();
                panelImagen.repaint();

我在以下行收到 java.lang.NullpointerException：img = new ImageIcon(ImageIO.read(is));

并在 ImageIcon 类上引用 Object o = image.getProperty("comment", imageObserver);。

请帮忙。

编辑。

这里是整个stackTrace

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at javax.swing.ImageIcon.<init>(ImageIcon.java:240)
at Datos.D_Clientes.getImageBytes(D_Clientes.java:242)
at Validations.OperacionImagen.bytesToIMG(OperacionImagen.java:71)
at Presentacion.Gestion_Clientes.tableClientesMouseClicked(Gestion_Clientes.java:410)
at Presentacion.Gestion_Clientes.access$700(Gestion_Clientes.java:14)
at Presentacion.Gestion_Clientes$8.mouseClicked(Gestion_Clientes.java:308)
at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:270)
at java.awt.Component.processMouseEvent(Component.java:6538)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
at java.awt.Component.processEvent(Component.java:6300)
at java.awt.Container.processEvent(Container.java:2236)
at java.awt.Component.dispatchEventImpl(Component.java:4891)
at java.awt.Container.dispatchEventImpl(Container.java:2294)
at java.awt.Component.dispatchEvent(Component.java:4713)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4534)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
at java.awt.Container.dispatchEventImpl(Container.java:2280)
at java.awt.Window.dispatchEventImpl(Window.java:2750)
at java.awt.Component.dispatchEvent(Component.java:4713)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.awt.EventQueue$4.run(EventQueue.java:729)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

【问题讨论】：

发布您的整个堆栈跟踪

标签： java sql database image exception

【解决方案1】：

我只是在方法中使用了 Blob：

 public static BufferedImage getImageBytes(int id) {
    BufferedImage image =null;
    byte[] imgData = null;
    try {

        String query = "exec [dbo].[sp_ObtenerImagen] '" + id + "'";
        Statement state = Constant.Conecctions().createStatement();
        ResultSet rs = state.executeQuery(query);
        while (rs.next()) {
            //is = rs.getBinaryStream(1);
            Blob img = rs.getBlob(1);
            imgData = img.getBytes(1, (int) img.length());
            try {
                image = ImageIO.read(new ByteArrayInputStream(imgData));
                //yourJLabelInstance.setIcon(new ImageIcon(image));
            } catch (IOException ex) {
                Logger.getLogger(D_Clientes.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    } catch (SQLException e) {
        e.printStackTrace();
    }

    return OperacionImagen.resize(image, 200, 200);
}

然后在 JPanel 之前将其插入到 Jlabel 中

【讨论】：