2021-11-04

点击验证码图片可以更换验证码，输入完成后点击确定按钮，可以判断验证码输入是否正确，效果如下图所示：

输入错误时(程序会清空输入框中的字符)：

正确时(不清空验证码输入框):

验证码图片生成类代码如下 ：

package basicValidcode;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.Random;

public class Createvalidcode {
//	存放获取的四个随机字符
	private String validcode_char = "";

//	下一个验证码
	private boolean is_nextvalidcode = false;
//	从这些字符中抓取显示的4个验证码字符
	String str_char = "qwertyuiopasdfghjklzxcvbnm1234567890QWERTYUIOPASDFGHJKLZXCVBNM"; 
	char[] charArray = str_char.toCharArray();
//	根据index索引，随机抓取4个字符		
	Random random = new Random();
	
	public BufferedImage createImage() {
//		创建图片缓冲区
		BufferedImage bf_image = new BufferedImage(80, 26,BufferedImage.TYPE_INT_RGB);
//		获取画笔对象
		Graphics g = bf_image.getGraphics();
//		设置画笔
		g.setColor(Color.GRAY);
		g.fillRect(0, 0, 80, 26);//填充矩形
		for(int i = 0;i<4;i++) {
			g.setColor(new Color(random.nextInt(252), random.nextInt(215), random.nextInt(192)));
			g.setFont(new Font("楷体", Font.BOLD, 26));
//			建立字符索引，以此来获得不同字符
			int index = 0;
			if(!is_nextvalidcode) {
				index = random.nextInt(str_char.length());
			}else {
				index = (random.nextInt(str_char.length()+5)%str_char.length());
			}
			String str = charArray[index]+"";
			g.drawString(str, i*13+13, 24);
			//将四个单独的随机字符用空字符（""）连接起来,得到4个字符的验证码
			setValidcode_char(getValidcode_char() + str);
		}
		return bf_image;
	}
	
//	生成下一个验证码
	public void nextvalidcode() {
		setValidcode_char("");
		is_nextvalidcode = true;
	}
	public String getValidcode_char() {
		return validcode_char;
	}
	public void setValidcode_char(String validcode_char) {
		this.validcode_char = validcode_char;
	}
}

窗口界面代码如下（包含验证码的输入判断）：
package basicValidcode;

import java.awt.EventQueue;

import javax.swing.ImageIcon;
import javax.swing.Jframe;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import java.awt.Toolkit;
import java.awt.Font;
import java.awt.Color;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class loginForm extends Jframe {

private static final long serialVersionUID = 1L;
private JPanel contentPane;
private JTextField textField;

// 生成验证码图片
Createvalidcode validcode;

public static void main(String[] args) {
	EventQueue.invokeLater(new Runnable() {
		public void run() {
			try {
				loginForm frame = new loginForm();
				frame.setResizable(false);//窗口大小不可更改
				frame.setLocationRelativeTo(null);//窗体在屏幕中居中显示
				frame.setVisible(true);
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
	});
}


public loginForm() {
	setForeground(Color.DARK_GRAY);
	setFont(new Font("Dialog", Font.BOLD, 11));
	setIconImage(Toolkit.getDefaultToolkit().getImage("C:\Users\huashi\Pictures\白衣天使.png"));
	setTitle("简易验证码实现");
	setDefaultCloseOperation(Jframe.EXIT_ON_CLOSE);
	setBounds(100, 100, 368, 272);
	contentPane = new JPanel();
	contentPane.setOpaque(false);
	contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
	setContentPane(contentPane);
	contentPane.setLayout(null);
	
	JLabel jlb_validcode = new JLabel("验证码");
	jlb_validcode.setForeground(new Color(255, 140, 0));
	jlb_validcode.setFont(new Font("宋体", Font.ITALIC, 17));
	jlb_validcode.setLabelFor(this);
	jlb_validcode.setBounds(56, 89, 53, 20);
	contentPane.add(jlb_validcode);
	
	textField = new JTextField();
	textField.setBounds(119, 87, 114, 26);
	contentPane.add(textField);
	textField.setColumns(10);
	
	validcode = new Createvalidcode();
	
	
	JLabel jlb_validcodeImage = new JLabel(new ImageIcon(validcode.createImage()));
	jlb_validcodeImage.addMouseListener(new MouseAdapter() {
		@Override
		public void mouseClicked(MouseEvent e) {
			validcode.nextvalidcode();
			jlb_validcodeImage.setIcon(new ImageIcon(validcode.createImage()));
		}
	});
	jlb_validcodeImage.setBounds(243, 87, 58, 26);
	contentPane.add(jlb_validcodeImage);
	
	JButton btn_yes = new JButton("确  定 ");
	btn_yes.addActionListener(new ActionListener() {
		public void actionPerformed(ActionEvent e) {
			if(is_validcode()) {
				JOptionPane.showMessageDialog(null, "验证码输入正确","提示消息",JOptionPane.WARNING_MESSAGE);
			}else {
				JOptionPane.showMessageDialog(null, "验证码输入错误，请重新输入！！！","提示消息",JOptionPane.WARNING_MESSAGE);
				textField.setText("");
			}
		}
	});
	btn_yes.setForeground(new Color(255, 127, 80));
	btn_yes.setFont(new Font("宋体", Font.BOLD, 17));
	btn_yes.setBounds(120, 166, 97, 30);
	contentPane.add(btn_yes);
	
	JLabel jlb_title = new JLabel("验证码生成");
	jlb_title.setForeground(new Color(255, 140, 0));
	jlb_title.setFont(new Font("幼圆", Font.BOLD, 17));
	jlb_title.setBounds(129, 20, 87, 20);
	contentPane.add(jlb_title);

// 背景图片设置
JLabel lblNewLabel = new JLabel("");
lblNewLabel.setIcon(new ImageIcon(“C:UsershuashiDesktopbackground2.jpg”));
lblNewLabel.setBounds(0, 0, 354, 225);
contentPane.add(lblNewLabel);
}
public boolean is_validcode() {
if(textField.getText().equals(validcode.getValidcode_char())) {
return true;
}
return false;
}
}

虽然很简单，但是我还是希望你自己跟着敲一遍代码，成功后自己在自己从头开始自己敲一遍，这样可以加深对验证码生成的理解。