mysql - 尝试使用 netbeans 程序将图像保存在 mysql 数据库中

Question

我正在构建一个食物菜单程序，用户将插入类别代码、类别名称并浏览合适的图像，该图像将作为 BLOB 存储在数据库中，然后单击保存。但是我在我的程序中遇到了这样的异常。

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
}

有人对我可能做错的事情有任何建议吗？

score 0 · Accepted Answer

st.setString(1, "\'"+codetext.getText()+"\'");
            st.setString(2,"\'"+ cat_name.getText()+"\'");
            st.setBytes(3, "\'"+cat_image+"\'");

score 0 · Accepted Answer

0

试试这个 st.execute();代替st.execute(sql);

于 2013-05-12T12:42:03.247 回答

mysql - 尝试使用 netbeans 程序将图像保存在 mysql 数据库中

2 回答 2

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