操作BLOB文件数据

1.
   数据库中的字段：private Blob pdf;

2.
   DAO文件操作：插入
SessionFactory   sf   =   getHibernateTemplate().getSessionFactory();
     Session s = sf.openSession(); 

Transaction tran=s.beginTransaction();
transientInstance.setPdf(Hibernate.createBlob(new byte[1]));
    s.save(transientInstance);
    s.flush();
    s.refresh(transientInstance,LockMode.UPGRADE);
    Blob blob=transientInstance.getPdf();
    InputStream is;
is = blob.getBinaryStream();
FileInputStream img = null;
try {
System.out.println("dao filePaht 11 == " + filePath);
String filePath1 = "";
try {
filePath1 = new String(filePath.getBytes("iso8859-1"),"utf-8");
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("dao filePaht 22 == " + filePath1);
img = new FileInputStream(filePath1);
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
Blob images = null;
try {
images = (Blob) Hibernate.createBlob(img);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}

transientInstance.setPdf(images);
System.out.println("save dao == " + transientInstance.getPdf());
    s.save(transientInstance);
   
    tran.commit();

    DAO操作 输出：
public String menuPdf(){

response = ServletActionContext.getResponse();

System.out.println("id == " + id);
menu = treeService.findById(id);
System.out.println("blob pdf == " + menu.getPdfid());
Nipdf nipdf = pdfService.findById(menu.getPdfid());
String fileName = nipdf.getName();

if(nipdf.getPdf() != null){
System.out.println("有BOLB文档了");

 
//Nipdf ni = pdfList.get(i);  
try {   
//从数据库中要读取出来   
System.out.println(nipdf.getPdf().length());
InputStream is = nipdf.getPdf().getBinaryStream();   
//在把写到一个图片格式的文件里   
FileOutputStream fos = new FileOutputStream("e:\\out_" + nipdf.getName());   

byte[] buffer = new byte[1024];   
int len = 0;   
//从数据库中读取到指定的字节数组中   
while((len = is.read(buffer) )!= -1){   
//从指定的数组中读取，然后输出来，所以这里buffer好象是连接inputStream和outputStream的一个东西   
fos.write(buffer,0,len);   
}   
} catch (FileNotFoundException e) {   
e.printStackTrace();   
} catch (SQLException e) {   
e.printStackTrace();   
} catch (IOException  e){   
e.printStackTrace();   
} 
}

return SUCCESS;

}