1.新建验证码生成接口:
/**
* 验证码生成逻辑抽象类
*
* @author zhaohaibin
*/
public interface ValidateCodeGenerator {
/**
* 验证码生成抽象方法
*
* @param request
* @return
*/
ImageCode generate(ServletWebRequest request);
}
2.接口实现,将ValidateCodeController实现逻辑提出:
/**
* 验证码生成逻辑实现类-图片验证码
*
* @author zhaohaibin
*/
@Data
public class ImageCodeGenerator implements ValidateCodeGenerator {
@Autowired
private SecurityProperties securityProperties;
@Override
public ImageCode generate(ServletWebRequest request) {
// 请求配置覆盖自定义配置覆盖默认配置
int width = ServletRequestUtils.getIntParameter(request.getRequest(), "width", securityProperties.getCode().getImage().getWidth());
int height = ServletRequestUtils.getIntParameter(request.getRequest(), "height", securityProperties.getCode().getImage().getHeight());
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
Random random = new Random();
g.setColor(getRandColor(200, 250));
g.fillRect(0, 0, width, height);
g.setFont(new Font("Times New Roman", Font.ITALIC, 20));
g.setColor(getRandColor(160, 200));
for (int i = 0; i < 155; i++) {
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(12);
int yl = random.nextInt(12);
g.drawLine(x, y, x + xl, y + yl);
}
String sRand = "";
for (int i = 0; i < securityProperties.getCode().getImage().getLength(); i++) {
String rand = String.valueOf(random.nextInt(10));
sRand += rand;
g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
g.drawString(rand, 13 * i + 6, 16);
}
g.dispose();
return new ImageCode(image, sRand, securityProperties.getCode().getImage().getExpireIn());
}
/**
* 生成随机背景条纹
*
* @param fc
* @param bc
* @return
*/
private Color getRandColor(int fc, int bc) {
Random random = new Random();
if (fc > 255) {
fc = 255;
}
if (bc > 255) {
bc = 255;
}
int r = fc + random.nextInt(bc - fc);
int g = fc + random.nextInt(bc - fc);
int b = fc + random.nextInt(bc - fc);
return new Color(r, g, b);
}
}
3.更新ValidateCodeController调用:
@Autowired
private ValidateCodeGenerator imageCodeGenerator;
@GetMapping("/code/image")
public void createCode(HttpServletRequest request, HttpServletResponse response) throws IOException {
ImageCode imageCode = imageCodeGenerator.generate(new ServletWebRequest(request));
sessionStrategy.setAttribute(new ServletWebRequest(request), SESSION_KEY, imageCode);
ImageIO.write(imageCode.getImage(), "JPEG", response.getOutputStream());
}
4.ValidateCodeGenerator注解@Component的替代方案,方便自定义生成逻辑的覆写:
/**
* 生成器实现方式可配置
* 效果同@Component,但是可以配置@ConditionalOnMissingBean,这样会优先寻找匹配name的生成实现方法
*
* @author zhaohaibin
*/
@Configuration
public class ValidateCodeBeanConfig {
@Autowired
private SecurityProperties securityProperties;
@Bean
@ConditionalOnMissingBean(name = "imageCodeGenerator")
public ValidateCodeGenerator imageCodeGenerator() {
ImageCodeGenerator codeGenerator = new ImageCodeGenerator();
codeGenerator.setSecurityProperties(securityProperties);
return codeGenerator;
}
}
5.测试自定义生成逻辑:
/**
* 自定义验证码生成逻辑
*
* @author zhaohaibin
*/
//@Component("imageCodeGenerator")
@Slf4j
public class DemoImageCodeGenerator implements ValidateCodeGenerator {
@Override
public ImageCode generate(ServletWebRequest request) {
log.info("更高级的图形验证码生成逻辑");
return null;
}
}
6.启动测试,图片不显示,控制台打印日志并报空指针异常表示成功:
INFO (DemoImageCodeGenerator.java:17)- 更高级的图形验证码生成逻辑
...
java.lang.NullPointerException: null
问题排查:
暂无