Captcha生成验证码，docker部署时字体包空指针异常

依赖

        
            com.github.penggle
            kaptcha
            2.3.2
        

配置类

package cn.penghf.lovemaster.config;

import com.google.code.kaptcha.impl.DefaultKaptcha;
import com.google.code.kaptcha.util.Config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.Properties;

@Configuration
public class KaptchaConfiguration {
    @Bean(name="captchaProducer")
    public DefaultKaptcha getKaptchaBean(){
        DefaultKaptcha defaultKaptcha=new DefaultKaptcha();
        Properties properties=new Properties();
        properties.setProperty("kaptcha.image.width", "160");
        properties.setProperty("kaptcha.image.height", "50");
        properties.setProperty("kaptcha.border", "no");
        //properties.setProperty("kaptcha.border.color", "105,179,90");
        properties.setProperty("kaptcha.textproducer.font.color", "255,103,51");
        properties.setProperty("kaptcha.textproducer.font.size","43");
        properties.setProperty("kaptcha.noise.color", "152,204,102");
        properties.setProperty("kaptcha.background.clear.from","130,129,179");
        properties.setProperty("kaptcha.background.clear.to","182,188,242");
        //properties.setProperty("kaptcha.session.key", "code");
        properties.setProperty("kaptcha.textproducer.char.length", "4");
        properties.setProperty("kaptcha.textproducer.char.space","5");
        properties.setProperty("kaptcha.textproducer.font.names", "宋体,楷体,微软雅黑");
        properties.setProperty("kaptcha.obscurificator.impl","com.google.code.kaptcha.impl.ShadowGimpy");
        properties.setProperty("kaptcha.background.impl","com.google.code.kaptcha.impl.DefaultBackground");
        Config config=new Config(properties);
        defaultKaptcha.setConfig(config);
        return defaultKaptcha;
    }
}

Controller

package cn.penghf.lovemaster.controller.security;

import cn.penghf.common.entity.security.Person;
import cn.penghf.common.utils.PKGenerator;
import cn.penghf.lovemaster.constants.CookieConstants;
import cn.penghf.lovemaster.constants.RedisConstants;
import cn.penghf.lovemaster.service.security.PersonService;
import cn.penghf.lovemaster.utils.http.CookieUtil;
import cn.penghf.lovemaster.utils.redis.RedisUtil;
import com.google.code.kaptcha.Producer;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.BufferedImage;
import java.io.IOException;

@Api("登录控制")
@RestController
@RequestMapping("/master/security/login")
@Slf4j
public class LoginController {

    @Autowired
    private Producer captchaProducer;

    @ApiOperation("验证码生成")
    @RequestMapping("/getValidateCode")
    public void getValidateCode(HttpServletResponse response){
        response.setDateHeader("Expires", 0);

        // Set standard HTTP/1.1 no-cache headers.
        response.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");
        // Set IE extended HTTP/1.1 no-cache headers (use addHeader).
        response.addHeader("Cache-Control", "post-check=0, pre-check=0");
        // Set standard HTTP/1.0 no-cache header.
        response.setHeader("Pragma", "no-cache");
        // return a jpeg
        response.setContentType("image/jpeg");
        // create the text for the image
        String capText = captchaProducer.createText();
        log.info("验证码："+capText);
        // store the text in the session
        String validateCodeId = PKGenerator.generateId();
        RedisUtil.set(String.format(RedisConstants.VALIDATECODE_PREFIX,validateCodeId),capText,RedisConstants.EXPIRE);
        //设置token到cookie
        CookieUtil.set(response, CookieConstants.VALIDATECODE , validateCodeId,CookieConstants.EXPIRE);
        // create the image with the text
        BufferedImage bi = captchaProducer.createImage(capText);
        // write the data out
        ServletOutputStream os = null;
        try {
            os = response.getOutputStream();
            ImageIO.write(bi, "jpg", os);
            os.flush();
            //return new RespBody(RespBody.StatusEnum.OK);
        } catch (IOException e) {
            log.error("获取验证码输出流异常",e);
            //return new RespBody(RespBody.StatusEnum.ERROR,"验证码获取异常");
        }finally {
            try {
                os.close();
            } catch (IOException e) {
                log.error("验证码输出流关闭异常",e);
                //return new RespBody(RespBody.StatusEnum.ERROR,"验证码获取异常");
            }
        }
    }
}

系统部署测试

docker部署

plugin

            
            
                com.spotify
                docker-maven-plugin
                1.0.0
                
                    ${docker.image.prefix}.${project.artifactId}
                    src/main/docker
                    
                        
                            /
                            ${project.build.directory}
                            ${project.build.finalName}.jar
                        
                    
                
            
            

Dockerfile

FROM openjdk:8-jdk-alpine
VOLUME /tmp
##时区
RUN echo "Asia/Shanghai" > /etc/timezone

#captcher 字体包
RUN set -xe \
&& apk --no-cache add ttf-dejavu fontconfig

ADD love-master-0.0.1-SNAPSHOT.jar love-master.jar
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/love-master.jar"]

openjdk:8-jdk-alpine 没有相关字体包，调用createImage()方法时，会报空指针异常，此处已经指定docker容器安装字体包

kaptcha相关配置参数参考

参考文章：

https://www.jianshu.com/p/370199b1625f