A simple example of MySQL blob access

One, get the MySQL connection

This is encapsulated as a method for easy use later.

Public Connection getconnection () throws exception{

String url = "Jdbc:mysql://localhost:3306/dbfortest";

String user = "root";

String password = "root";

Class.forName ("Com.mysql.jdbc.Driver");

Connection conn = drivermanager.getconnection (URL, user, password);

Return conn;

}

Ii. storing data in a database

/**

*

* @param file that needs to be passed into the database

* @throws Exception

*/

public void Save (file file) throws exception{

Connection conn = getconnection ();

String sql = "INSERT into Tb_blob (name,myfile) VALUES (?,?)";

PreparedStatement prest = conn.preparestatement (sql);

String Filename=file.getname ();

Prest.setstring (1, filename);//save by file name

FileInputStream fis = new FileInputStream (file);

Prest.setblob (2, Fis,file.length ());//The second parameter requires a InputStream

Prest.execute (); Perform

}

Take out the data and write the file at the same time.

/**

*

* @param the value of the filename column and is the file name

* @throws Exception

*/

public void GetMp3 (String filename) throws exception{

Connection conn = getconnection ();

String sql = "SELECT * from Tb_blob where name=?";

PreparedStatement prest = conn.preparestatement (sql);

Prest.setstring (1, filename);

ResultSet rs = Prest.executequery ();

while (Rs.next ()) {

Blob bl = Rs.getblob ("myfile");//data is saved in "MyFile", here is the data saved here.

InputStream is = Bl.getbinarystream (); View blobs, which can be taken out in the form of streams.

Bufferedinputstream Buffis = new Bufferedinputstream (IS);

Save to Buffout, in the project directory under FileName file

Bufferedoutputstream buffout = new Bufferedoutputstream (new FileOutputStream (filename));

Byte[] buf= new byte[1024];

int len = buffis.read (buf, 0, 1024);

while (len>0) {

Buffout.write (BUF);

Len=buffis.read (buf, 0, 1024);

}

Buffout.flush ();

Buffout.close ();

Buffis.close ();

}

}

A simple example of MySQL blob access