小编Yuh*_* Su的帖子

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;


public class Cards extends JFrame {

private GridLayout grid1;

    JButton []bt=new JButton[52];

    ImageIcon tail=new ImageIcon(getClass().getResource("b1fv.png"));

    ImageIcon ori;

    public Cards(){
        grid1=new GridLayout(7,9,2,2);
        setLayout(grid1);
        for(int i=0;i<bt.length;i++){
            ImageIcon c=new ImageIcon(getClass().getResource(i+1+".png"));
            bt[i]=new JButton(c);
            bt[i].addActionListener(new RatingMouseListener(i));
            add( bt[i]);
        }
    }

    public static void main(String[] args){
        Cards frame=new Cards();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(1400,700);
        frame.setVisible(true);
    }

    private class RatingMouseListener implements ActionListener {
        private  int index=0;


        public RatingMouseListener(int index) {
            this.index = index;

        }




        public void actionPerformed(ActionEvent e) {
              System.out.println("Mouse entered for rating " …

public class L20 {
public static void main(String[] args) throws IOException{
    Scanner input=new Scanner(System.in);

    System.out.println("Enter file name");
    String in=input.nextLine();
    try{
        textWriter(in);
        textReader(in);
        textChanger(in);

    }catch(Exception e){

    }

}

public static void textWriter(String path) throws IOException{
    String[] alphabet=    
 {"a","b","c","d","e","f","g","h","i","j","k","m","l","n","o","p","q","r","s","t","u","v","w","x","y","z"};
File file=new File(path);
Writer output=null;
    Random number=new Random();
    output=new BufferedWriter(new FileWriter(file));
    int lines=10+number.nextInt(11);
    for(int i=0;i<lines;i++){
    int it2=1+number.nextInt(9);
    int n1=number.nextInt(26);
    int n2=number.nextInt(26);
    int n3=number.nextInt(26);

    String t2=Integer.toString(it2);
    String t1=alphabet[n1]+alphabet[n2]+alphabet[n3];
    String text=t1+t2;
    output.write(text);
    ((BufferedWriter) output).newLine();
    }
    output.close();
    System.out.println("Your file has been written");
}

public static void …