想要读出lob里面的图片数据,就要确认clob里面存储的是什么,一般情况下存储的base64的串串.所以就以base64为例,而Blob里面存储的大部分是图片数据,但也有xml内容数据.

1查询lob字段内容

Clob clob = rs.getClob(fieldName); Blob blob = rs.getBlob(fieldName);

2base64解码

private byte[] getClobData(Clob clob){        byte[] bt = null;        BASE64Decoder decoder = new BASE64Decoder();        try {            String base64Str = clob.getSubString(1, (int) clob.length());            bt = decoder.decodeBuffer(base64Str);        } catch (Exception e) {            logger.error("读取clob数据出错", e);        }        return bt;    }

private byte[] getBlobData(Blob blob) {        BufferedInputStream is = null;        byte[] bt = null;        try {            is = new BufferedInputStream(blob.getBinaryStream());            int bufferSize = (int)blob.length();            bt = new byte[bufferSize];            try {                is.read(bt, 0, bufferSize);            } catch (Exception e) {                logger.error("读取Blob数据出错", e);            }        } catch (Exception e) {            logger.error("读取Blob字段内容出错", e);        } finally {            if (is != null) {                try {                    is.close();                } catch (Exception e) {                }                is = null;            }        }        return bt;    }

3lob数据保存到本地

private void saveDataToLocal(byte[] bt){        try{            String fileName = "E:/test.jpg";　　　　//String fileName = "E:/test.xml"            FileOutputStream out= null;            out= new FileOutputStream(fileName);            out.write(bt, 0, bt.length);            out.close();        }catch(Exception e){            e.printStackTrace();        }    }