存放文件到数据库(包括存放和提取文件).ppt

1、把文件存放到数据库（包含存放和提取）,-实例,/* * 程序信息：把文件加入到数据库当中 * 主要使用pstmt.setBinaryStream(3, fis, (int)(f.length(); * 数据字段类型blob图片 * author Tree *2012-3-29下午07:18:30 */ public class SaveFile public static void main(String args) File f=new File(D:xunlei新建文件夹13156155064381521.jpg); try Class.forName(com.mysql.jdbc.Dri

2、ver); Connection con=DriverManager.getConnection( jdbc:mysql:/localhost:3306/test, root, root); String sql=INSERT INTO users(username,password,jpg)VALUES(?,?,?); String sql2=update users set jpg=? where id=?; PreparedStatement pstmt=con.prepareStatement(sql2); pstmt.setString(2, 1); /pstmt.setString

3、(2, abc2); FileInputStream fis=new FileInputStream(f); /length方法返回的是long类型、必须强制转换成int、不然mysql驱动包没有实现setBinaryStream其他的重载方法 pstmt.setBinaryStream(1, fis, (int)(f.length(); pstmt.execute(); pstmt.close(); con.close(); catch (ClassNotFoundException e) / TODO Auto-generated catch block e.printStackTrace

4、(); catch (SQLException e) / TODO Auto-generated catch block e.printStackTrace(); catch (FileNotFoundException e) / TODO Auto-generated catch block e.printStackTrace(); ,/* * 程序信息：把文件从数据库当中提取出来 * 数据字段类型blob图片 * * author Tree 2012-3-29下午07:18:30 */ public class ReadFile public static void main(String

5、 args) String time = new SimpleDateFormat(yyyyMMddHHmmssSS) .format(new Date(); File f = new File(D: + time + .jpg); try Class.forName(com.mysql.jdbc.Driver); Connection con = DriverManager.getConnection( jdbc:mysql:/localhost:3306/test, root, root); String sql = Select * from users where id=1; Stat

6、ement stmt = con.createStatement(); ResultSet rs = stmt.executeQuery(sql); while (rs.next() InputStream is = rs.getBinaryStream(jpg); FileOutputStream fos = new FileOutputStream(f); byte buffer = new byte512; int length; while (length = is.read(buffer, 0, buffer.length) != -1) fos.write(buffer, 0, length); fos.flush()