upload file (pdf,JPEG/FIF) to mysql using java

Question

Is there any way to attach file to mysql in java? I need the file to be inside the database not the path.

Answer 1

This is example code of how one can write a binary file like a PDF document, a MS Excel spreadsheet, a JPG/PNG image file or a ZIP file, etc.. to a database table column of type BLOB, and read from the database.

I had used these with Java SE 7 or greater with the Apache Derby (a.k.a. Java DB) and MySQL databases respectively.

Derby: Write to db:

Path path = Paths.get("MyPic.jpg");
InputStream instream = Files.newInputStream(path);
PreparedStatement pstmnt = getConnection().prepareStatement(dml); // dml is an sql Insert   
pstmnt.setBinaryStream(1, instream);
// pstmnt.setNull(1, Types.BLOB); // to set null value in db
pstmnt.executeUpdate();
pstmnt.close();
instream.close();

Read from db:

PreparedStatement pstmnt = getConnection().prepareStatement(sql); // sql is a Select
ResultSet rs = pstmnt.executeQuery();
rs.next();
InputStream instream = rs.getBinaryStream("col_name");
Path path = Paths.get("MyPic.jpg");
OutputStream outstream = Files.newOutputStream(path);
int len = 0;
byte [] buf = new byte [1024];
while ((len = instream.read(buf)) > 0) {
    outstream.write(buf, 0, len);
}
instream.close();
outstream.flush();
outstream.close();      
pstmnt.close();

MySQL: Write to db:

PreparedStatement pstmnt_= conn.prepareStatement(DML) // sql Insert
InputStream instream = Files.newInputStream(filePath); // filePath is of type Path
pstmnt.setBinaryStream(1, instream);
pstmnt.executeUpdate();
// close resources here

Read from db:

PreparedStatement pstmnt = conn.prepareStatement(DML); // sql Select
ResultSet rs = pstmnt.executeQuery();
rs.next();
Blob blob = rs.getBlob("col_name");
long len = blob.length();
byte [] fileBytes = blob.getBytes(1L, (int) len); // start pos = 1L
OutputStream out = ...
out.write(fileBytes);
out.flush();
out.close();

Note that after using the JDBC objects (e.g., PreparedStatement) and file io streams (e.g., InputStream) make sure these resources are closed.

Answer 2

Use base64 enconding and save it as BLOB data

This is an example of encoding:

/**
 * Method used for encode the file to base64 binary format
 * @param file
 * @return encoded file format
 */
private String encodeFileToBase64Binary(File file){
    String encodedfile = null;
    try {
        FileInputStream fileInputStreamReader = new FileInputStream(file);
        byte[] bytes = new byte[(int)file.length()];
        fileInputStreamReader.read(bytes);
        encodedfile = Base64.encodeBase64(bytes).toString();
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    return encodedfile;
}