JDBC实现oracle blob 出库入库
1，首先建一个足够简单的表imageTable
id varchar（20）
image blob
2，blob入库
拷贝Sunset.jpg图片在C盘根目录下

一般是先通过select ... for update锁定blob列，然后写入blob值，然后提交。要用到特定的Oracle BLOB类。

1 DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
2 Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:beyondduke","duke","duke");
3 conn.setAutoCommit(false);
4 BLOB blob = null;
5 PreparedStatement pstmt = conn.prepareStatement("insert into imageTable(id,image) values(?,empty_blob())");
6 pstmt.setString(1,"10001");
7 pstmt.executeUpdate();
8 pstmt.close();
9 pstmt = conn.prepareStatement("select content from imageTable where id= ? for update");
10 pstmt.setString(1,"10001");
11 ResultSet rs = pstmt.executeQuery();
12 if (rs.next()) blob = (BLOB) rs.getBlob(1);
13 String fileName = "c://Sunset.jpg";
14 File f = new File(fileName);
15 FileInputStream fin = new FileInputStream(f);
16 System.out.println("file size = " + fin.available());
17 pstmt = conn.prepareStatement("update imageTable set image=? where id=?");
18 OutputStream out = blob.getBinaryOutputStream();
19 byte[] data = new byte[(int)fin.available()];
20 fin.read(data);
21 out.write(data);
22 out.close();
23 fin.close();
24
25 pstmt.setBlob(1,blob);
26 pstmt.setString(2,"fankai");
27
28 pstmt.executeUpdate();
29 pstmt.close();
30
31 conn.commit();
32 conn.close();

浏览数据库的数据，发现image项中数据大小与图片大小 一致，说明入库了！

1 DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
2 Connection conn = DriverManager.getConnection( "jdbc:oracle:thin:@localhost:1521:beyondduke", "duke","duke");
conn.setAutoCommit(
false);
3 Statement stmt = conn.createStatement();
4 /* 查询BLOB对象 */
5 ResultSet rs = stmt.executeQuery("SELECT content FROM javatest WHERE id='1001'");
6 while (rs.next()) {
7 /* 取出此BLOB对象 */
8 oracle.sql.BLOB blob = (oracle.sql.BLOB) rs.getBlob("image");
9 BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream("d://Sunset.jpg"));
BufferedInputStream in = new BufferedInputStream(blob .getBinaryStream());
10 int c;
11 while ((c = in.read()) != -1) { out.write(c);
12 }
13 in.close();
14 out.close();
15 rs.close();
16 stmt.close();
17 conn.close();
18

检查D盘根目录，会发现Sunset.jpg文件，跟C盘下是一样的，说明入库出库成 功！