Java-操作MySql-Blob-字段

Java 操作MySql Blob 字段import java.sql.*;import java.io.*;import javax.swing.*;import java.awt.*;import java.awt.event.*;class myImgConnection conn;Statement st;PreparedStatement ps,pu;ResultSet rs;JLabel l1;JFrame f;JFileChooser jf;String fn;JTextField t1,t2;JButton bi,bimg,bf,bp,bn,bl;JPanel p1,p2,p3,p4;myImg()f=new JFrame(图片字段操作);f.setDefaultCloseOperation(3);f.setBounds(100,100,600,500);jf=new JFileChooser(.);Container c=f.getContentPane();c.setLayout(new BorderLayout();p1=new JPanel();p2=new JPanel();p3=new JPanel();p4=new JPanel();p4.setLayout(new BorderLayout();bi=new JButton(插入记录);bf=new JButton(第一条记录);bp=new JButton(上一条记录);bn=new JButton(下一条记录);bl=new JButton(最后条记录);bimg=new JButton(修改照片);t1=new JTextField(10);t2=new JTextField(10);p3.add(t1);p3.add(bi);p3.add(bimg);p2.add(t2);p2.add(p3);p2.add(bf);p2.add(bp);p2.add(bn);p2.add(bl);p4.add(p2,Center);p4.add(p3,South);l1=new JLabel();p1.add(l1);c.add(p1,North);c.add(p4,South);f.setVisible(true);tryClass.forName(com.mysql.jdbc.Driver);conn=DriverManager.getConnection(jdbc:mysql:/127.0.0.1:3306/myschool,root,root);ps=conn.prepareStatement(insert into img values(null,?,?);pu=conn.prepareStatement(Update img set Img=? where SName=?);st=conn.createStatement();rs=st.executeQuery(select * from img);rs.next();mm();catch(ClassNotFoundException ex)catch(SQLException exx)bf.addActionListener(new ActionListener()public void actionPerformed(ActionEvent e) tryrs.first();mm();catch(SQLException ex);bp.addActionListener(new ActionListener()public void actionPerformed(ActionEvent e) tryrs.previous();mm();catch(SQLException ex);bn.addActionListener(new ActionListener()public void actionPerformed(ActionEvent e) tryrs.next();mm();catch(SQLException ex);bl.addActionListener(new ActionListener()public void actionPerformed(ActionEvent e) tryrs.last();mm();catch(SQLException ex)System.out.println(error););bi.addActionListener(new ActionListener()public void actionPerformed(ActionEvent e) InputStream in=null;if(jf.showDialog(f,插入图片)=JFileChooser.APPROVE_OPTION);fn=jf.getSelectedFile().getPath();tryFile f=new File(fn);in=new FileInputStream(f);ps.setString(2,t1.getText().trim();ps.setBinaryStream(1,in,(int)f.length();pu.executeUpdate();rs=st.executeQuery(select * from img);catch(SQLException exx)System.out.println(error1);catch(IOException ex)System.out.println(error2););bimg.addActionListener(new ActionListener()public void actionPerformed(ActionEvent e) InputStream in=null;if(jf.showDialog(f,插入图片)=JFileChooser.APPROVE_OPTION);fn=jf.getSelectedFile().getPath();tryFile f=new File(fn);in=new FileInputStream(f);pu.setBinaryStream(1,in,(int)f.length();pu.setString(2,t2.getText().trim();pu.executeUpdate();rs=st.executeQuery(select * from img);catch(SQLException exx)System.out.println(error1);catch(IOException ex)System.out.println(error2););void mm() throws SQLExceptiont2.setText(rs.getString(2);Blob blob=rs.getBlob(3);if(blob!=nul