从数据库获取BLOB，如何将它们放回原处 [英] Get BLOB from database, how to put them back

问题描述

我从数据库中获取了BLOB数据，并使用以下代码将其放入字符串中(rs是ResultSet，文件是Map)，有没有办法将此字符串值放回到BLOB列中? /p>

I got the BLOB data from the database and use the below code to put it into a string(rs is the ResultSet, file is a Map), is there a way to put this string value back to the BLOB columns?

                    Blob blob = rs.getBlob("FILE_DATA");
                    if(blob != null) {
                        byte[] bdata = blob.getBytes(1, (int) blob.length());
                        String data = new String(bdata);
                        file.put("FILE_DATA", data);
                    }

我已经尝试过一些类似的建议，但是效果不佳.

I have tried some suggestions like this one, but they don't work well.

            Blob blbVal = getConnection().createBlob();
            byte[] fileData = value.toString().getBytes();
            blbVal.setBytes(1, fileData);
            cs.setBlob(index, blbVal);

推荐答案

我发现将BLOB放入String的方式也不正确，如果不对BLOB数据进行编码，它将丢失.

I found out that the way I put the BLOB into the String is also not correct, if we don't encode the BLOB data, it will be lost.

在这里，我找到了另一个帖子，可以完美解决此问题.感谢BalusC的回答 如何用JSON表示数据库中的图像

Here I found another post which solved this issue perfectly. Thanks for BalusC's answer How to represent an image from database in JSON

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