我正在构建一个JAVA Netbeans和MySQL程序，用户可以在其中插入图像并将其更新到数据库中。它成功插入。我已将这些图像设置为在Jlabel中显示。但是一旦我更新了该图像，它就会更新，但图像不会显示在Jlabel中。请帮我解决这个问题。这是我的代码
package Frames;
import Methods.DB_Con;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.sql.*;
import javax.swing.*;
import net.proteanit.sql.DbUtils;
public class EditCategory extends javax.swing.JFrame {
private ImageIcon format=null;
String filename = null;
int s = 0;
byte[] category_image = null;
public void Update_Table(){
try{
ResultSet rs;
Connection con = DB_Con.getConnection();
String sql ="select Category_Code,Category_Name from category";
PreparedStatement st = (PreparedStatement) con.prepareStatement(sql);
rs=st.executeQuery();
jTable1.setModel(DbUtils.resultSetToTableModel(rs));
st.close();
}
catch(Exception e){
JOptionPane.showMessageDialog(null, "Error loading table");
}
}
public void set_Icon(){
try{
int row= jTable1.getSelectedRow();
jLabel4.setText(jTable1.getModel().getValueAt(row, 0).toString());
jTextField1.setText(jTable1.getModel().getValueAt(row, 1).toString());
Connection con = DB_Con.getConnection();
ResultSet rs;
String cat_id=jTable1.getModel().getValueAt(row, 0).toString();
String sql ="select Category_Image from category where Category_Code='"+cat_id+"'";
PreparedStatement st = (PreparedStatement) con.prepareStatement(sql);
rs = st.executeQuery();
if(rs.next()){
byte[] imagedata=rs.getBytes("Category_Image");
format =new ImageIcon(imagedata);
jLabel1.setIcon(format);
}
}
catch(Exception e){
}
}
/** Creates new form EditCategory */
public EditCategory() {
initComponents();
}
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jLabel12 = new javax.swing.JLabel();
jScrollPane1 = new javax.swing.JScrollPane();
jTable1 = new javax.swing.JTable();
jButton2 = new javax.swing.JButton();
jButton3 = new javax.swing.JButton();
jLabel5 = new javax.swing.JLabel();
jLabel1 = new javax.swing.JLabel();
jPanel1 = new javax.swing.JPanel();
jLabel4 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jButton1 = new javax.swing.JButton();
jTextField2 = new javax.swing.JTextField();
jLabel3 = new javax.swing.JLabel();
jTextField1 = new javax.swing.JTextField();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
addWindowFocusListener(new java.awt.event.WindowFocusListener() {
public void windowGainedFocus(java.awt.event.WindowEvent evt) {
formWindowGainedFocus(evt);
}
public void windowLostFocus(java.awt.event.WindowEvent evt) {
}
});
addWindowListener(new java.awt.event.WindowAdapter() {
public void windowOpened(java.awt.event.WindowEvent evt) {
formWindowOpened(evt);
}
});
jLabel12.setBackground(new java.awt.Color(255, 255, 255));
jLabel12.setFont(new java.awt.Font("Tahoma", 0, 36));
jLabel12.setForeground(new java.awt.Color(255, 0, 0));
jLabel12.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
jLabel12.setText("Edit Category");
jLabel12.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED, null, new java.awt.Color(0, 153, 255), null, null));
jTable1.setBackground(new java.awt.Color(204, 204, 255));
jTable1.setModel(new javax.swing.table.DefaultTableModel(
new Object [][] {
},
new String [] {
"", ""
}
) {
Class[] types = new Class [] {
java.lang.Integer.class, java.lang.Object.class
};
boolean[] canEdit = new boolean [] {
false, false
};
public Class getColumnClass(int columnIndex) {
return types [columnIndex];
}
public boolean isCellEditable(int rowIndex, int columnIndex) {
return canEdit [columnIndex];
}
});
jTable1.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
jTable1MouseClicked(evt);
}
});
jScrollPane1.setViewportView(jTable1);
jTable1.getColumnModel().getColumn(0).setResizable(false);
jTable1.getColumnModel().getColumn(1).setResizable(false);
jButton2.setText("Done");
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
jButton3.setText("Back");
jButton3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton3ActionPerformed(evt);
}
});
jLabel5.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
jLabel5.setText("**Click on table row to get values to edit**");
jLabel5.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED, null, new java.awt.Color(0, 153, 255), null, null));
jLabel1.setBackground(new java.awt.Color(204, 255, 204));
jLabel1.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
jLabel1.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED));
jPanel1.setBackground(new java.awt.Color(204, 204, 204));
jPanel1.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED));
jLabel4.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
jLabel4.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED));
jLabel2.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
jLabel2.setText("Edit Category Name");
jLabel2.setBorder(javax.swing.BorderFactory.createEtchedBorder());
jButton1.setText("Browse New Image");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jLabel3.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
jLabel3.setText("Category Code");
jLabel3.setBorder(javax.swing.BorderFactory.createEtchedBorder());
jTextField1.setHorizontalAlignment(javax.swing.JTextField.CENTER);
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 150, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(100, 100, 100)
.addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, 440, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(10, 10, 10)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jLabel3, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jLabel2, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 128, Short.MAX_VALUE))
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(112, 112, 112)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 440, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
.addGap(112, 112, 112)
.addComponent(jLabel4, javax.swing.GroupLayout.PREFERRED_SIZE, 440, javax.swing.GroupLayout.PREFERRED_SIZE)))))
.addContainerGap())
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel4, javax.swing.GroupLayout.PREFERRED_SIZE, 20, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel3, javax.swing.GroupLayout.PREFERRED_SIZE, 20, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(16, 16, 16)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel2, javax.swing.GroupLayout.PREFERRED_SIZE, 22, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(28, 28, 28)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jButton1)
.addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap())
);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(195, 195, 195)
.addComponent(jButton2, javax.swing.GroupLayout.PREFERRED_SIZE, 109, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(209, 209, 209)
.addComponent(jButton3, javax.swing.GroupLayout.PREFERRED_SIZE, 76, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(218, 218, 218))
.addGroup(layout.createSequentialGroup()
.addGap(61, 61, 61)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 437, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 115, Short.MAX_VALUE)
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 140, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(87, 87, 87))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(288, Short.MAX_VALUE)
.addComponent(jLabel12, javax.swing.GroupLayout.PREFERRED_SIZE, 280, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(272, 272, 272))
.addGroup(layout.createSequentialGroup()
.addGap(160, 160, 160)
.addComponent(jLabel5, javax.swing.GroupLayout.PREFERRED_SIZE, 246, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(434, Short.MAX_VALUE))
.addGroup(layout.createSequentialGroup()
.addGap(28, 28, 28)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(98, Short.MAX_VALUE))
);
layout.linkSize(javax.swing.SwingConstants.HORIZONTAL, new java.awt.Component[] {jButton2, jButton3});
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel12, javax.swing.GroupLayout.PREFERRED_SIZE, 60, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 138, javax.swing.GroupLayout.PREFERRED_SIZE))
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 120, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(33, 33, 33)
.addComponent(jLabel5, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(29, 29, 29)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(37, 37, 37)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton2)
.addComponent(jButton3))
.addContainerGap(41, Short.MAX_VALUE))
);
java.awt.Dimension screenSize = java.awt.Toolkit.getDefaultToolkit().getScreenSize();
setBounds((screenSize.width-856)/2, (screenSize.height-593)/2, 856, 593);
}// </editor-fold>
private void jTable1MouseClicked(java.awt.event.MouseEvent evt) {
set_Icon();
}
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
JFileChooser chooser = new JFileChooser();
chooser.showOpenDialog(null);
File f = chooser.getSelectedFile();
filename = f.getAbsolutePath();
jTextField2.setText(filename);
try {
File image = new File(filename);
FileInputStream fis = new FileInputStream(image);
ByteArrayOutputStream bos = new ByteArrayOutputStream();
byte buf[] = new byte[1024];
for (int readNum; (readNum = fis.read(buf)) != -1;) {
bos.write(buf, 0, readNum);
}
category_image = bos.toByteArray();
} catch (Exception e) {
JOptionPane.showMessageDialog(null, e);
}
}
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
EditMenuMain em = new EditMenuMain();
em.setVisible(true);
this.setVisible(false);
}
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
try{
int code=Integer.parseInt(jLabel4.getText());
String newCatName = jTextField1.getText();
Connection con = DB_Con.getConnection();
String sql ="update category set Category_Name='"+ newCatName+"',Category_Image='"+category_image+"' where Category_Code='"+code+"'";
PreparedStatement st = (PreparedStatement) con.prepareStatement(sql);
int val = st.executeUpdate(sql);
if(val==1){
JOptionPane.showMessageDialog(null, "Updated Category Details Successfuly");
}
else{
JOptionPane.showMessageDialog(null, "Fill all fields");
}
}
catch(Exception e){
}
Update_Table();
}
private void formWindowOpened(java.awt.event.WindowEvent evt) {
Update_Table();
}
private void formWindowGainedFocus(java.awt.event.WindowEvent evt) {
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new EditCategory().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JButton jButton3;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel12;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JLabel jLabel5;
private javax.swing.JPanel jPanel1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTable jTable1;
private javax.swing.JTextField jTextField1;
private javax.swing.JTextField jTextField2;
// End of variables declaration
}
答案 0 :(得分：0)
ImageIcon构造函数无法确定图像数据的格式。请尝试ImageIO.read()方法：http://docs.oracle.com/javase/1.4.2/docs/api/javax/imageio/ImageIO.html#read(java.io.InputStream）
将您的字节数组包裹在ByteArrayInputStream：http://docs.oracle.com/javase/6/docs/api/java/io/ByteArrayInputStream.html
答案 1 :(得分：0)
Connection connection = null;
PreparedStatement statement = null;
ResultSet result;
public DisplayImage() {
super("Image Display");
setSize(600,600);
connection = getConnection();
try {
statement = connection.prepareStatement("select content from image where id=1");
result = statement.executeQuery();
byte[] image = null;
while(result.next()) {
image = result.getBytes("content");
}
Image img = Toolkit.getDefaultToolkit().createImage(image);
ImageIcon icon =new ImageIcon(img);
JLabel lPhoto = new JLabel();
lPhoto.setIcon(icon);
add(lPhoto);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
setVisible(true);
}
public Connection getConnection() {
Connection connection = null;
try {
Class.forName("com.mysql.jdbc.Driver");
connection = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/db_name", "user", "pass");
} catch (Exception e) {
System.out.println("Error Occured While Getting the Connection: - "
+ e);
}
return connection;
}
public static void main(String[] args) {
new DisplayImage();
}
}