blob, convert byte binary to pdf

base64 is used to decode and decode, and the encrypted encode source jar must be consistent.
Before decrypting, change " " into ""
for some jars that cannot be entered into the lib//jdkjar package and use add aviralbale to configure the

large fields:
--alter table TB_PRE_AUDIT_POLICY_INFO add(tmp blob);
alter table TB_PRE_AUDIT_POLICY_INFO rename column POLICYCONTENT to POLICYCONTENT_bak;
alter table TB_PRE_AUDIT_POLICY_INFO rename column tmp to POLICYCONTENT;

when deleting, you must first turn the blob into empty();
when operating a blob, pay attention to closing the stream in time, etc., especially to write things back, otherwise it will be rolled back due to for Update locks the table


pdf: 1, the document is written (the built-in elements of the pdf will be added automatically); 2, the others themselves are pdfs, which are passed down in binary, this is if. Truncated, if there are fewer elements, then if there are fewer built-in elements in the pdf, the pdf cannot be opened.