JDBC stores and reads binary data, and jdbc stores binary data.

JDBC stores and reads binary data, and jdbc stores binary data.

The following JSP files are uploaded using the common-fileupload component and stored in the database as binary files.

<% If ("POST ". equalsIgnoreCase (request. getMethod) {// if it is a POST form DiskFileUpload diskFileUpload = newDiskFileUpload (); diskFileUpload. setHeaderEncoding ("UTF-8"); // sets the encoding // parses the uploaded data List <FileItem> list = diskFileUpload. parseRequest (request); for (FileItem fileItem: list) {if (! FileItem. isFormField () {// if it is a file domain // file path, replace the special character String filename = fileItem. getName (). replace ("\", "/"); // obtain the filename = filename. substring (filename. lastIndexOf ("/") + 1); // obtain the file type String filetype = fileItem. getContentType (); // get the file size Int filesize = fileItem. getSize (); Connection conn = null; PrepareStatement preStmt = null; try {conn = DbManager. getConnection (); preStmt = conn. prepareStatement ("inser T into table_name (filename, filetype, size, content, date) values (?,?,?,?,?) "); PreStmt. setString (1, filename); preStmt. setString (2, filetype); preStmt. setInt (3, filesize); preStmt. setBinaryStream (4, fileItem. getInputStream (), filesize); preStmt. setTimestamp (5, newTimestamp (System. currentTimeMills (); preStmt.exe cuteUpdate ();} finally {if (preStmt! = Null) preStmt. close (); if (conn! = Null) conn. close () ;}}}%>

 

Read Binary files

<% Out. clear (); // clear all output int id = Integer. parseInt (request. getParameter ("id"); // obtain the attachment ID Connection conn = null; PrepareStatementpreStmt = null; ResultSet rs = null; try {conn = DbManager. getConnection (); preStmt = conn. prepareStatement ("select from table_name where id =? "); PreStmt. setInt (1, id); rs initialize prestmt.exe cuteQuery (); if (rs. next () {response. reset (); // reset response. setContentType (rs. getString ("fileType"); // sets the output file type response. setContentLength (ra. getInt ("filesize"); // set the length of the output file. InputStream ins = null; OutputStream ous = null; try {ins = rs. getBinaryStream ("content"); ous = response. getOutputStream (); byte [] B = new byte [1024]; int len = 0; while (len = I Ns. read (B ))! =-1) {ous. write (B, 0, len) ;}} finally {if (ous! = Null) ous. close (); if (ins! = Null) ins. close () ;}} else {out. println ("No Attachment Found:" + id) ;}} finally {if (rs! = Null) rs. close (); if (preStmt! = Null) preStmt. close (); if (conn! = Null) conn. close () ;}%>