JDBC操作二进制类型数据

//JDBC操作二进制类型数据（如图片或压缩包）也是通过IO字节流形式操作

public class BlobTest {

 

    public static void main(String[] args) throws SQLException, IOException {

       // create();

       read();

    }

    //查询

    static void read() throws SQLException, IOException {

       Connection conn = null;

       Statement st = null;

       ResultSet rs = null;

       try {

           // 2.建立连接

           conn = JdbcUtils.getConnection();

           // conn = JdbcUtilsSing.getInstance().getConnection();

           // 3.创建语句

           st = conn.createStatement();

           // 4.执行语句

           rs = st.executeQuery("select big_bit  from blob_test");

           // 5.处理结果

           while (rs.next()) {

              // Blob blob = rs.getBlob(1);

              // InputStream in = blob.getBinaryStream();

              InputStream in = rs.getBinaryStream("big_bit");

              File file = new File("IMG_0002_bak.jpg");

              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(rs, st, conn);

       }

    }

    //添加：

    static void create() throws SQLException, IOException {

       Connection conn = null;

       PreparedStatement ps = null;

       ResultSet rs = null;

       try {

           // 2.建立连接

           conn = JdbcUtils.getConnection();

           // conn = JdbcUtilsSing.getInstance().getConnection();

           // 3.创建语句

           String sql = "insert into blob_test(big_bit) values (?) ";

           ps = conn.prepareStatement(sql);

           File file = new File("IMG_0002.jpg");

InputStream in = new BufferedInputStream(new FileInputStream(file));

 

           ps.setBinaryStream(1, in, (int) file.length());

           // 4.执行语句

           int i = ps.executeUpdate();

           in.close();

 

           System.out.println("i=" + i);

       } finally {

           JdbcUtils.free(rs, ps, conn);

       }
    }
}