Java implementation file conversion to binary storage and extraction

First, function Description:

The files are converted into binary data into the database, and when needed, they can be removed for installation and use.

Second, the database:

Create a database field to store the image into binary, this field has a requirement is to set the BLOB type of

[SQL]View Plaincopy

1. CREATE TABLE ' save_image ' (
2. ' ID ' int (a) is not NULL auto_increment,
3. <span style="color: #FF0000;" > ' images ' blob</span>
4. PRIMARY KEY (' id ')
5. )

Third, convert the file into binary data and save the Java code:

[Java]View Plaincopy

2. Public Void Save () throws SQLException
4. {
6. Connection=connectionmanager.getconn (); //Connect to the database and connect to your own database
10. try {
12. File file=new file ("d:\\1.jpg"); The file to convert
14. FileInputStream inputstream=New FileInputStream (file);
16. String sql="insert into save_image (images) VALUES (?)"; The SQL statements that are stored in the database must be executed with preparestatement
18. Statement=connection.preparestatement (SQL);
20. Statement.setbinarystream (1, InputStream, (int) file.length ());
22. Statement.executeupdate ();
26. } catch (FileNotFoundException e) {
28. //TODO auto-generated catch block
30. E.printstacktrace ();
32. } catch (SQLException e) {
34. //TODO auto-generated catch block
36. E.printstacktrace ();
38. }
42. }

Four, take out the data and restore the file to the local Java code:

[Java]View Plaincopy

2. Reading a database binary file
4. Public void Readerjpg () throws SQLException
6. {
8. Connection=connectionmanager.getconn ();  //Connect to your own database!!!!!!!!
10. String sqlstring="Select images from Save_image where id=4"; Read the binary code from the database to restore the file, here I read my own database ID 4 file
12. File file=new file ("e:\\1.jpg"); Locally generated files
14. if (!file.exists ())
16. {
18. try {
20. File.createnewfile ();
22. } catch (Exception e) {
24. E.printstacktrace ();
26. }
30. }
32. try {
34. byte[] Buffer = new byte[4096*5];
36. Statement=connection.preparestatement (sqlString);
38. ResultSet = Statement.executequery ();
40. if (Resultset.next ())
42. {
44. FileOutputStream outputstream = new FileOutputStream (file);
46. InputStream IStream = Resultset.getbinarystream ("Images"); Go to field with Getbinarystream ()
48. int size=0;
50. While ((Size=istream.read (Buffer))!=-1)
52. {
54. SYSTEM.OUT.PRINTLN (size);
56. Outputstream.write (Buffer,0,size);
58. }
60. }
62. } catch (Exception e) {
64. E.printstacktrace ();
66. }
70. }

Java implementation file conversion to binary storage and extraction