我正在构建一个食物菜单程序，用户将插入类别代码，类别名称，并浏览一个合适的图像，该图像将作为BLOB存储在数据库中并单击“保存”。但是我在我的程序中遇到了例外情况。
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '?,?,?)' at line 1
这是我的代码：
package Frames;
import Methods.DB_Con;
import com.mysql.jdbc.Connection;
import com.mysql.jdbc.PreparedStatement;
import com.mysql.jdbc.Statement;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.util.Random;
import javax.swing.JFileChooser;
import javax.swing.JOptionPane;
/**
*
* @author ASHAN
*/
public class AddCategory extends javax.swing.JFrame {
String filename = null;
int s = 0;
byte[] cat_image = null;
/** Creates new form AddMenu */
public AddCategory() {
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();
jButton1 = new javax.swing.JButton();
jButton2 = new javax.swing.JButton();
codetext = new javax.swing.JTextField();
jLabel1 = new javax.swing.JLabel();
cat_name = new javax.swing.JTextField();
jButton3 = new javax.swing.JButton();
jTextField2 = new javax.swing.JTextField();
jButton4 = new javax.swing.JButton();
jDesktopPane1 = new javax.swing.JDesktopPane();
jLabel2 = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
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("Add Category");
jLabel12.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED, null, new java.awt.Color(0, 153, 255), null, null));
jButton1.setText("Browse for Image");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jButton2.setText("Generate Code");
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
jLabel1.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
jLabel1.setText("Category Name");
jButton3.setText("Save");
jButton3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton3ActionPerformed(evt);
}
});
jButton4.setText("Back");
jButton4.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton4ActionPerformed(evt);
}
});
jLabel2.setBounds(0, 0, 150, 130);
jDesktopPane1.add(jLabel2, javax.swing.JLayeredPane.DEFAULT_LAYER);
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(216, 216, 216)
.addComponent(jLabel12, javax.swing.GroupLayout.PREFERRED_SIZE, 280, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(229, Short.MAX_VALUE))
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.CENTER)
.addGroup(layout.createSequentialGroup()
.addComponent(jButton2, javax.swing.GroupLayout.DEFAULT_SIZE, 119, Short.MAX_VALUE)
.addGap(138, 138, 138)
.addComponent(codetext, javax.swing.GroupLayout.DEFAULT_SIZE, 159, Short.MAX_VALUE))
.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
.addComponent(jLabel1, javax.swing.GroupLayout.DEFAULT_SIZE, 119, Short.MAX_VALUE)
.addGap(138, 138, 138)
.addComponent(cat_name, javax.swing.GroupLayout.DEFAULT_SIZE, 159, Short.MAX_VALUE)))
.addGap(299, 299, 299))
.addGroup(layout.createSequentialGroup()
.addGap(194, 194, 194)
.addComponent(jButton3, javax.swing.GroupLayout.PREFERRED_SIZE, 107, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(55, 55, 55)
.addComponent(jButton4, javax.swing.GroupLayout.PREFERRED_SIZE, 98, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(271, Short.MAX_VALUE))
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jButton1, javax.swing.GroupLayout.DEFAULT_SIZE, 119, Short.MAX_VALUE)
.addGap(138, 138, 138)
.addComponent(jTextField2, javax.swing.GroupLayout.DEFAULT_SIZE, 159, Short.MAX_VALUE)
.addGap(76, 76, 76)
.addComponent(jDesktopPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 147, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(76, 76, 76))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(20, 20, 20)
.addComponent(jLabel12, javax.swing.GroupLayout.PREFERRED_SIZE, 60, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(58, 58, 58)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton2)
.addComponent(codetext, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(cat_name, javax.swing.GroupLayout.PREFERRED_SIZE, 22, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 24, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(73, 73, 73)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jButton1)
.addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 125, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton3)
.addComponent(jButton4))
.addGap(42, 42, 42))
.addGroup(layout.createSequentialGroup()
.addGap(251, 251, 251)
.addComponent(jDesktopPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 131, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(107, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
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);
}
cat_image = bos.toByteArray();
} catch (Exception e) {
JOptionPane.showMessageDialog(null, e);
}
}
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
Random rand = new Random();
int n = rand.nextInt(90000) + 10000;
codetext.setText(Integer.toString(n));
}
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
try {
Connection con = DB_Con.getConnection();
String sql = "insert into category (cat_code,cat_name,cat_image) values (?,?,?)";
PreparedStatement st = (PreparedStatement) con.prepareStatement(sql);
//int code=Integer.parseInt(codetext.getText());
// st.setInt(1, code);
st.setString(1, codetext.getText());
st.setString(2, cat_name.getText());
st.setBytes(3, cat_image);
st.execute(sql);
st.close();
JOptionPane.showMessageDialog(null, "Details Successfully Added");
} catch (Exception e) {
// JOptionPane.showMessageDialog(null, e);
System.out.println(e);
}
}
private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {
AddMenuMain am = new AddMenuMain();
am.setVisible(true);
this.setVisible(false);
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new AddCategory().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JTextField cat_name;
private javax.swing.JTextField codetext;
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JButton jButton3;
private javax.swing.JButton jButton4;
private javax.swing.JDesktopPane jDesktopPane1;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel12;
private javax.swing.JLabel jLabel2;
private javax.swing.JTextField jTextField2;
// End of variables declaration
}
有没有人对我可能做错了什么有任何建议？
答案 0 :(得分：0)
st.setString(1, "\'"+codetext.getText()+"\'");
st.setString(2,"\'"+ cat_name.getText()+"\'");
st.setBytes(3, "\'"+cat_image+"\'");
答案 1 :(得分：0)
尝试使用此st.execute();代替st.execute(sql);