如何从MySQL读取LONGBLOB

问题描述

我有一个pdf作为LONGBLOB存储在数据库中。

我需要使用Groovy脚本检索二进制输出流。

我试过这个：

  rowTest = sql.firstRow（select data from mytable id = 666）; 
 file = rowTest [0]; 
 myLongBlob =（oracle.sql.BLOB）文件;但是，我得到了一个强制异常：
 
 
  javax.script.ScriptException：javax.script.ScriptException：org.codehaus.groovy.runtime.typehandling.GroovyCastException：无法通过类'[B']投射对象'[B @ 48eb2326'到类'oracle.sql.BLOB'
  
然后我意识到我试图把一个LONGBLOB BLOB这可能是为什么这个错误发生的原因？
 
 
 
无论如何，还有另一种方式从LONGBLOB读取我的PDF？
 
 
 
感谢。
 
 
 
编辑：错误不是由于将LONGBLOB转换为BLOB，我尝试使用BLOB并发生相同的错误。 
 
 
编辑：我试图遵循本教程： 
解决方案
一个对象'[B @ 48eb2326'是指字节数组;在 rowTest [0] 的对象是 byte [] ，而不是 code>。所以最简单的事情可能是 byte [] myLongBlob =（byte []）文件（这可能更方便你使用，反正！）。 > 
I have a pdf stored in a database as a LONGBLOB.
I need to retrieve it binary output stream with a Groovy script.
I've tried this :
rowTest = sql.firstRow("select data from mytable id = 666");
file = rowTest[0];
myLongBlob = (oracle.sql.BLOB)file;
However, I get a cast exception :
javax.script.ScriptException: javax.script.ScriptException: org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot cast object '[B@48eb2326' with class '[B' to class 'oracle.sql.BLOB'
Then I realized I was trying to cast a LONGBLOB to a BLOB which is probably the reason why this error happens ?
Anyway, is there another way to read my PDF from a LONGBLOB ?
Thanks.
Edit : The error is not due to casting a LONGBLOB to BLOB, I tried with a BLOB and same error happens.
Edit : I'm trying to follow this tutorial : http://groovy.codehaus.org/Reading+from+a+Blob
 解决方案 
An object '[B@48eb2326' refers to a byte array; the object at rowTest[0] is a byte[], not a Blob. So the easiest thing would probably be byte[] myLongBlob = (byte[]) file (which is probably more convenient for you to work with, anyway!).
                        
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