JDBC编程实现文件、图片的存储方法

/*实现的功能： 用数据库存储文本数据，并且读取出来放在当前项目里分析： 难度不是很大，关键是掌握文件流，数据库的操作不是很多，但是文件流的读写比较多日期：20131003作者：烟大阳仔*/public class Ckb_test { public static void main(String[] args) throws SQLException, IOException {  // TODO Auto-generated method stub  read(); } static void create() throws SQLException, IOException {  Connection conn=null;  PreparedStatement prest=null;  ResultSet resultset=null;  try {   //2.建立连接   conn=JdbcUtils.getConnection();   //单例设计模式   conn=JdbcUtilsSingle.getInstance().getConnection();   //3.创建语句   String sql="insert into ckb_test(text) values(?)";   prest=conn.prepareStatement(sql);   File file=new File("src/cn/com/JDBC/JdbcUtils.java");   Reader reader=new BufferedReader(new FileReader(file));   prest.setCharacterStream(1, reader, (int)file.length());   //4.执行语句   int i=prest.executeUpdate();   reader.close();   System.out.println("i="+i);  } finally  {   JdbcUtils.free(resultset, prest, conn);  } } static void read() throws SQLException, IOException {  Connection conn=null;  Statement st=null;  ResultSet resultset=null;  try {   //2.建立连接   conn=JdbcUtils.getConnection();   //单例设计模式   conn=JdbcUtilsSingle.getInstance().getConnection();   //3.创建语句   st=conn.createStatement();   //4.执行语句   resultset=st.executeQuery("select text from ckb_test");   //5.处理结果   while(resultset.next())   {    Clob clob=resultset.getClob(1);    Reader reader=clob.getCharacterStream();    //reader=resultset.getCharacterStream(1);    File file=new File("JdbcUtils.java");    Writer writer=new BufferedWriter(new FileWriter(file));    char[] buff=new char[1024];    for(int i=0;(i=reader.read(buff))>0;)    {     writer.write(buff,0,i);    }    writer.close();    reader.close();   }  } finally  {   JdbcUtils.free(resultset, st, conn);  } }}/*实现的功能： 用数据库存储图片数据，并且读取出来放在当前项目里分析： 难度不是很大，关键是掌握字节流，数据库的操作不是很多，但是文件流的读写比较多，注意更改图片的目录日期：20131003作者：烟大阳仔*/public class PictureBlob { public static void main(String[] args) throws SQLException, IOException {  read(); } static void create() throws SQLException, IOException {  Connection conn=null;  PreparedStatement prest=null;  ResultSet resultset=null;  try {   //2.建立连接   conn=JdbcUtils.getConnection();   //单例设计模式   conn=JdbcUtilsSingle.getInstance().getConnection();   //3.创建语句   String sql="insert into blob_test(big_bit) values(?)";   prest=conn.prepareStatement(sql);   File file=new File("C://Documents and Settings//Administrator//My Documents//My Pictures//cxg.jpg");   InputStream in=new BufferedInputStream(new FileInputStream(file));   prest.setBinaryStream(1, in, (int)file.length());   //4.执行语句   int i=prest.executeUpdate();   in.close();   System.out.println("i="+i);  } finally  {   JdbcUtils.free(resultset, prest, conn);  } } static void read() throws SQLException, IOException {  Connection conn=null;  Statement st=null;  ResultSet resultset=null;  try {   //2.建立连接   conn=JdbcUtils.getConnection();   //单例设计模式   conn=JdbcUtilsSingle.getInstance().getConnection();   //3.创建语句   st=conn.createStatement();   //4.执行语句   resultset=st.executeQuery("select big_bit from blob_test");   //5.处理结果   while(resultset.next())   {    Blob blob=resultset.getBlob(1);    InputStream in=blob.getBinaryStream();    //reader=resultset.getCharacterStream(1);    File file=new File("1.jpeg");    OutputStream out=new BufferedOutputStream(new FileOutputStream(file));    byte[] buff=new byte[1024];    for(int i=0;(i=in.read(buff))>0;)    {     out.write(buff,0,i);    }    out.close();    in.close();   }  } finally  {   JdbcUtils.free(resultset, st, conn);  } }}