验证码

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

import java.util.Random;

import javax.swing.JComponent;

public class yanzhengCode extends JComponent implements MouseListener {

private String codes; //自动生成的验证码

private int width, height = 40; //设置验证码高度、宽度

private int codesLength = 4; //设置代码长度

private Random random = new Random(); //生成数字的方法

public yanzhengCode() {
width = this.codesLength * 16 + (this.codesLength - 1) * 10; //根据验证码长度设置宽度
setPreferredSize(new Dimension(width, height)); //设置背景大小
setSize(width, height); //设置验证码长度和宽度
this.addMouseListener(this);
setToolTipText("点击可更换验证码");
}
//得到生成的验证码
public int getCodesLength() {
return codesLength;
}


//设置验证码的长度
public void setCodesLength(int codeLength) {
if(codesLength < 4) {
this.codesLength = 4;
} else {
this.codesLength = codeLength;
}

}

public String getCode() {
return codes;
}


//让验证码产生随机的颜色
public Color getRandColor(int min, int max) {

if (min > 255)
min = 255;
if (max > 255)
max = 255;
int red = random.nextInt(max - min) + min;
int green = random.nextInt(max - min) + min;
int blue = random.nextInt(max - min) + min;
return new Color(red, green, blue);
}
// 设置验证码具体的数字或字母是什么
protected String generateCode() {
char[] codes = new char[this.codesLength];
for (int i = 0, len = codes.length; i < len; i++) {
if (random.nextBoolean()) {
codes[i] = (char) (random.nextInt(10) + 48);
} else {
codes[i] = (char) (random.nextInt(26) + 97);
}
}
this.codes = new String(codes);
return this.codes;
}


@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if(this.codes == null || this.codes.length() != this.codesLength) { //判断生成的验证码是否为空或超出长度
this.codes = generateCode();
}
width = this.codesLength * 16 + (this.codesLength - 1) * 10;
super.setSize(width, height); //接口使用，验证码字体大小
super.setPreferredSize(new Dimension(width, height));//接口使用，验证码背景大小
Font mFont = new Font("Arial", Font.BOLD | Font.ITALIC, 25); //设置字体和字体大小
g.setFont(mFont); //设置对象
//绘制出验证码的背景的矩形轮廓
Graphics2D g2d = (Graphics2D) g;
g2d.setColor(getRandColor(200, 250));
g2d.fillRect(0, 0, width, height);
g2d.setColor(getRandColor(180, 200));
g2d.drawRect(0, 0, width - 1, height - 1);
//绘制出验证码背景的线
int i = 0, len = 150;
for (; i < len; i++) {
int x = random.nextInt(width - 1);
int y = random.nextInt(height - 1);
int x1 = random.nextInt(width - 10) + 10;
int y1 = random.nextInt(height - 4) + 4;
g2d.setColor(getRandColor(180, 200));
g2d.drawLine(x, y, x1, y1);
}



//绘制出验证码的具体字母
i = 0; len = this.codesLength;
FontMetrics fm = g2d.getFontMetrics();
int base = (height - fm.getHeight())/2 + fm.getAscent();
for(;i<len;i++) {
int b = random.nextBoolean() ? 1 : -1;
g2d.rotate(random.nextInt(10)*0.01*b);
g2d.setColor(getRandColor(20, 130));
g2d.drawString(codes.charAt(i)+"", 16 * i + 10, base);
}
}

//下一个验证码
public void nextCode() {
generateCode();
repaint();
}

@Override
public void mouseClicked(MouseEvent e) {

nextCode();
}

@Override
public void mousePressed(MouseEvent e) {
// TODO Auto-generated method stub

}

@Override
public void mouseReleased(MouseEvent e) {
// TODO Auto-generated method stub

}

@Override
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub

}

@Override
public void mouseExited(MouseEvent e) {
// TODO Auto-generated method stub

}
}