create sequence seq_blobmodel_id start with 1 increment by 1 nocache;
create table blobmodel
(
blobid number(10) primary key not null,
image blob
); 

将文件写入数据库

/**
* 将图片文件存入数据库
* @throws SQLException
* @throws IOException
*/
public int writeBlob(String path) throws SQLException, IOException{
int result = 0;
String sql = "insert into blobmodel(blobid,image) values(seq_blobmodel_id.nextval,?)";
//1.创建Blob
Blob image = DBHelper.getConnection().createBlob();
//2.将流放入blob
OutputStream out = image.setBinaryStream(1);
//3.读取图片,并写入输出流
FileInputStream fis = new FileInputStream(path);
byte []buf = new byte[1024];
int len = 0;
while((len=fis.read(buf))!=-1){
out.write(buf, 0, len);
}
result = DBHelper.executeUpdate2(sql, new Object[]{image});//自己简单封装了jdbc操作
fis.close();
out.close();
return result;
}

/**
* 将数据库中的图片文件读出来
* @throws SQLException 
* @throws IOException 
*/
public void readBlob() throws SQLException, IOException{
String sql = "select image from blobmodel where blobid=?";
DBHelper.getConnection();//
ResultSet rs = DBHelper.executeQuery(sql, new Object[]{1});
while(rs.next()){
Blob image = rs.getBlob(1);
InputStream is = image.getBinaryStream();
BufferedInputStream bis = new BufferedInputStream(is);
String path = "img/"+new Date().getTime()+".jpg";//指定输出的目录为项目下的img文件夹
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(path));
byte []buf = new byte[1024];
int len = 0;
while((len=bis.read(buf))!=-1){
bos.write(buf,0,len);
}
bos.close();
bis.close();
}
}