Hello Friend,

Try these codes:

1)

import java.io.*;

public class CopyFile {
    private static void copyfile(String srcfile,String destfile) {
        try {
            File f1 = new File(srcfile);
            File f2 = new File(destfile);
            InputStream in = new FileInputStream(f1);
            OutputStream out = new FileOutputStream(f2, true);
            byte[] buf = new byte[1024];
            int len;
            while ((len = in.read(buf)) > 0) {
                out.write(buf, 0, len);
            }
            in.close();
            out.close();
            System.out.println("File copied.");
        } catch (Exception ex) {
            System.out.println(ex);
        }
    }

    public static void main(String[] args)throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        System.out.println("Source File: ");
        String srcFile=reader.readLine();
        System.out.println("Desination File: ");
        String destFile=reader.readLine();

        copyfile(srcFile,destFile);
    }
}

2)

import java.sql.*;

class DatabaseOperations{
    public static void main(String[] args){
    try{
      Class.forName("com.mysql.jdbc.Driver").newInstance();
      Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","root");
      Statement st = con.createStatement(); 
      String name="roseindia";
      String address="delhi";
      int i = st.executeUpdate("INSERT INTO data(name, address) VALUES ('"+name+"','"+address+"')");
      System.out.println("Data is inserted!");
      int j=st.executeUpdate("update data set name='rose' where id='1'");
      System.out.println("Data is updated!");
      ResultSet rs=st.executeQuery("select * from data");
      while(rs.next()){
      System.out.println(rs.getString("name")+"     "+rs.getString("address"));
      }
      int k=st.executeUpdate("delete from data where id='1'");
      System.out.println("One row is deleted!");
    }
    catch(Exception e){
        e.printStackTrace();
    }
    }
}

For the above code, we have created a table named 'data' in the database:

CREATE TABLE `data` (                                     
          `id` bigint(30) NOT NULL auto_increment,                
          `name` varchar(255) default NULL,                       
          `address` varchar(255) default NULL,                
          PRIMARY KEY  (`id`)                                     
        )

3)

import java.util.*;

class  CountRepeatedNumber {
  public static void main(String[] args) throws Exception{
  Scanner input=new Scanner(System.in);
 System.out.print("Enter number of multiple digits: ");
 long num=input.nextLong();
  String st=Long.toString(num);

  char[]third =st.toCharArray();
  for(int counter =0;counter<third.length;counter++){
  char ch= third[counter];
  int count=0;
  for ( int i=0; i<third.length; i++){
  if (ch==third[i])
  count++;
}
boolean flag=false;
for(int j=counter-1;j>=0;j--){
if(ch==third[j])
flag=true;
}
if(!flag){
if(count>1){
System.out.println("Number "+ch+" is repeated "+count+" times ");
}
}
}
}
}