JAVA存取Oracle的BFile和LOBs

//通过JDBC从oracle里面取BFile（LOB）类型数据存储到磁盘

  /**
   *
   * @author Liu Yuanyuan
   */
 Private void getBFile()
{
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;
        try
        {
            String driver = "oracle.jdbc.driver.OracleDriver";
            String url = "jdbc:oracle:thin:@127.0.0.1 :1521:orcl";
            Class.forName(driver);
            System.out.println("class");
            conn = DriverManager.getConnection(url, "lyy", "lyy");
            System.out.println("connect");
            stmt = conn.createStatement();
            String sql = "select files from lyy.filetable";
            rs = stmt.executeQuery(sql);
            System.out.println("sql="+sql);
            while (rs.next())
            {   System.out.println(rs.getMetaData().getColumnTypeName(1));
                BFILE b = (BFILE)rs.getObject(1);// BLOB b = (BLOB)rs.getObject(1);
                OutputStream ops = null;
                InputStream ips = null;
                File file = new File("e:"+File.separator+b.getName());//getName() only for BFILE
                try
                {
                    System.out.println("isFileExist = "+b.fileExists());//fileExists() only for BFILE
                    //For BFILE,must open File,and close File after its operation 
                    //for BLOB,needn’t openFile() and closeFile()
                    b.openFile();                  
                    ips = b.getBinaryStream();
                    byte[] buffer =new byte[b.getBytes().length];//
                    ops = new FileOutputStream(file);
                    //将文件写到硬盘
                    for (int i; (i = ips.read(buffer)) > 0;)
                   {                      
                        ops.write(buffer, 0, i);
                        ops.flush();
                    }
                    b.closeFile();
                }
                catch (Exception ex)
                {
                    ex.printStackTrace(System.out);
                }
                finally
                {
                    ips.close();
                    ops.close();
                }
            }
        }
        catch (Exception ex)
        {
            ex.printStackTrace(System.out);
        }
        finally
        {
            try
            {
                if(rs!=null)
                {
                   rs.close();
                }
                if(stmt!=null)
                {
                   stmt.close();
                }
                if(conn!=null)
                {
                   conn.close();
                }
            }
            catch (SQLException ex)
            {
               ex.printStackTrace(System.out);
            }
        }
}

常见错误：

ORA-22925 getting large LOB via JDBC Thin 11.2

This problem is introduced in JDBC 11.2.Read of a LOB above 2GB in size can fail in JDBC Thin in 11.2 .

也就是说对于通过JDBC读取的LOB值的上限是2G。

//将硬盘上的直接文件存入Oracle(BFile或者BLOB)

注：直接存文件对文件大小有一定限制，查处后会内存溢出，稍后将介绍for update的方法

Private void insertBinary()
{
        String driver = "oracle.jdbc.driver.OracleDriver";
        String url = "jdbc:oracle:thin:@127.0.0.1 :1521:orcl";
        Connection conn = null;
        PreparedStatement ps = null;
        try
        {
            Class.forName(driver);
            System.out.println("success find class");
            conn = DriverManager.getConnection(url, "lyy", "lyy");
            System.out.println("success connect");
            String sql = "insert into rawtable(id,obj) values(?,?)";
            ps = conn.prepareStatement(sql);
            ps.setInt(1, 1122);
            //设置二进制BLOB参数
            File file = new File("d:\\lyy.txt");
            InputStream is = new FileInputStream(file);
            ps.setBinaryStream(2, is, (int) file.length());
            //设置二进制CLOB参数
            // File file_clob = new File("c:\\a.txt");
            //InputStreamReader reader = new InputStreamReader(new FileInputStream(file_clob));

            // ps.setCharacterStream(3, reader, (int) file_clob.length());
            ps.executeUpdate();
            is.close();
        }
        catch (Exception ex)
        {
            ex.printStackTrace(System.out);
        }
        finally
        {
            try
            {
                if(ps!=null)
                ps.close();
                if(conn!=null)
                conn.close();
            }
            catch (SQLException ex)
            {
               Logger.getLogger(GetBlob.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
}