The first one: import jar package com.github.axet generation method
①Guide package
<dependency>
<groupId>com.github.axet</groupId>
<artifactId>kaptcha</artifactId>
<version> 0.0.9</version>
</dependency>
② Create a configuration class to configure the verification code generation
Configuration class
@Configuration
public class KaptchaConfig {
@Bean
public DefaultKaptcha producer(){
Properties properties = new Properties();
//（选择性的设置，不是每个都需要设置）
//是否需要外边框（yes,no）
properties.put(“kaptcha.border”,“yes”);
//边框厚度，合法值：>0
properties.put(“kaptcha.border.thickness”,“2”);
//框颜色，合法值： r,g,b (and optional alpha) 或者 white,black,blue
properties.put(“kaptcha.border.color”,“blue”);
//字体颜色
properties.put(“kaptcha.textproducer.font.color”,“black”);
//渲染效果：水纹：WaterRipple；鱼眼：FishEyeGimpy；阴影：ShadowGimpy
// properties.put(“kaptcha.obscurificator.impl”,“com.google.code.kaptcha.impl.FishEyeGimpy”);
//配置干扰线–噪点(只改变最后一个单词：NoNoise,DefaultNoise)
properties.put(“kaptcha.noise.impl”,“com.google.code.kaptcha.impl.DefaultNoise”);
//干扰 颜色，合法值： r,g,b 或者 white,black,blue.
properties.put(“kaptcha.noise.color”,“yellow”);
//设置图片及字体
properties.put(“kaptcha.image.width”,“90”);
properties.put(“kaptcha.image.height”,“33”);
properties.put(“kaptcha.textproducer.font.size”,“25”);
//生成验证码的长度（也就是要几个字）
properties.put(“kaptcha.textproducer.char.length”,“4”);
//文字间隔
properties.put(“kaptcha.textproducer.char.space”,“5”);
//和登录框背景颜色一致
//背景颜色渐变，开始颜色
properties.put(“kaptcha.background.clear.from”,“247,247,247”);
//背景颜色渐变， 结束颜色
properties.put(“kaptcha.background.clear.to”,“247,247,247”);
properties.put(“kaptcha.word.impl”,“com.google.code.kaptcha.text.impl.DefaultWordRenderer”);
Config config = new Config(properties);
DefaultKaptcha defaultKaptcha = new DefaultKaptcha();
defaultKaptcha.setConfig(config);
return defaultKaptcha;
}
}
Control class
③ Call the class generated by the picture (generally the Controller layer)
@Controller
@RequestMapping("/producer")
public class KaptchaController {
@Autowired
private Producer producer;
@RequestMapping("/kaptcha")
public void produceKaptcha(HttpServletRequest request, HttpServletResponse response) throws Exception{
response.setHeader(“Cache-Control”, “no-store, no-cache”);
response.setContentType(“image/jpeg”);
//生成文字验证码
String text = producer.createText();
System.out.println(text);
/**
*在此处做text的缓存，方便登陆校验
* 例如：HttpSession session=re.getSession();
* session.setAttribute(“code”, sb.toString());
**/
//生成图片验证码
BufferedImage image = producer.createImage(text);
ServletOutputStream out = response.getOutputStream();
ImageIO.write(image,“jpg”,out);
}
}
Second: Write your own verification code generation method
**
①Control layer (writing at the call site)
control layer
@RequestMapping("/selfdefinitionkaptcha")
public void selfDefinitionKaptcha(HttpServletResponse response) throws Exception{
Object[] objs = CreateKaptcha.createImage();
String text = (String) objs[0];
/**
* 缓存验证码
*ShiroUtils.setSessionAttribute(Constants.KAPTCHA_SESSION_KEY, text);
*/
BufferedImage image =
(BufferedImage) objs[1];
response.setHeader(“Cache-Control”, “no-store, no-cache”);
response.setContentType(“image/jpeg”);
ServletOutputStream out = response.getOutputStream();
ImageIO.write(image, “png”, out);
}
②Verification code generation class
public class CreateKaptcha {
// 验证码字符集
private static final char[] chars = {
‘0’, ‘1’, ‘2’, ‘3’, ‘4’, ‘5’, ‘6’, ‘7’, ‘8’, ‘9’,
‘A’, ‘B’, ‘C’, ‘D’, ‘E’, ‘F’, ‘G’, ‘H’, ‘I’, ‘J’, ‘K’, ‘L’, ‘M’, ‘N’,
‘O’, ‘P’, ‘Q’, ‘R’, ‘S’, ‘T’, ‘U’, ‘V’, ‘W’, ‘X’, ‘Y’, ‘Z’};
private static Map<String,String> map = new HashMap<String,String>();
private static List list= new ArrayList();
static{
map.put(“李白的女儿”,“李紫嫣”);
map.put(“31*51=?”, “1581”);
map.put(“潘金莲的老公”, “武大郎”);
map.put(“dnf外号”, “毒奶粉”);
map.put(“你是猪吗”, “是”);
map.put(“光头强职业”, “伐木工”);
map.put(“床前明月光”,“疑是地上霜”);
map.put(“天王盖地虎”,“宝塔镇河妖”);
Set set=map.keySet();
for(String s:set){
list.add(s);
}
set=null;
}
// 字符数量
private static final int SIZE = 4;
// 干扰线数量
private static final int LINES = 5;
// 宽度
private static final int WIDTH = 130;
// 高度
private static final int HEIGHT = 35;
// 字体大小
private static final int FONT_SIZE =15;
/**
* 生成随机验证码及图片
**/
public static Object[] createImage() {
StringBuffer sb = new StringBuffer();
// 1.创建空白图片
BufferedImage image = new BufferedImage(
WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
// 2.获取图片画笔
Graphics graphic = image.getGraphics();
// 3.设置画笔颜色
graphic.setColor(Color.LIGHT_GRAY);
// 4.绘制矩形背景
graphic.fillRect(0, 0, WIDTH, HEIGHT);
// 5.画随机字符
Random ran = new Random();
if(ran.nextInt(2)==0){
for (int i = 0; i <SIZE; i++) {
// 取随机字符索引
int n = ran.nextInt(chars.length);
// 设置随机颜色
graphic.setColor(getRandomColor());
// 设置字体大小
int size=(ran.nextInt(15)+FONT_SIZE);
graphic.setFont(new Font(
null, Font.ITALIC,size ));
// 画字符
graphic.drawString(
chars[n] + “”, i * WIDTH /SIZE, HEIGHT/2+5);
// 记录字符
sb.append(chars[n]);
}
}else{
String key = list.get(ran.nextInt(list.size()));
char[] cha = key.toCharArray();
graphic.setColor(new Color(0,0,0));
for(int i=0;i<cha.length;i++){
int size = WIDTH/cha.length-2;
graphic.setFont(new Font(null,Font.ITALIC+1,size));
graphic.drawString(cha[i]+"", iWIDTH/cha.length, HEIGHT/2+5);
}
char[] value=map.get(key).toCharArray();
for(int i=0;i<value.length;i++){
sb.append(value[i]);
}
}
// 6.画干扰线
for (int i = 0; i < LINES; i++) {
// 设置随机颜色
graphic.setColor(getRandomColor());
// 随机画线
graphic.drawLine(ran.nextInt(WIDTH), ran.nextInt(HEIGHT),
ran.nextInt(WIDTH), ran.nextInt(HEIGHT));
}
// 7.返回验证码和图片
return new Object[]{sb.toString(), image};
}
/**
* 随机取色
*/
public static Color getRandomColor() {
Random ran = new Random();
Color color = new Color(ran.nextInt(256),
ran.nextInt(256), ran.nextInt(256));
return color;
}
}
Summary:
1. The first one is simpler, the second one is better and easier to control. You can also do more tricks, such as: addition, subtraction, multiplication and division, Tang poetry and Song Ci, you can.
I love the second one more.
2. Two methods adopt two different methods for the caching of verification codes. ShiroUtils.setSessionAttribute () needs to use shiro
