You have seen earlier how to store a file in database table office. Let us retrieve the file (Retrieve File JDBC), "Expenditure.txt" from table and write into another file "Liabilities.txt".
Example in Retrieve File JDBC
import java.io.*;
import java.sql.*;
public class RetrieveFile
{
public static void main(String[] args) throws Exception
{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection con = DriverManager.getConnection("jdbc:odbc:snrao", "scott", "tiger");
PreparedStatement pst = con.prepareStatement("select * from office");
ResultSet res = pst.executeQuery();
res.next(); // move the pointer first row
Clob c1 = res.getClob(2); // 2 indicates the second field in office table
Reader r1 = c1.getCharacterStream();
FileWriter fw = new FileWriter("C:\\Liabilities.txt");
int k;
while((k = r1.read()) != -1)
{
fw.write((char)k);
}
System.out.println("File is retrieved");
fw.close();
r1.close();
res.close();
pst.close();
con.close();
}
}
please provide an example to download image from an url and from a database.
also for these concepts provide step by step explanation as before for better understanding.