SpringBoot实现Thymeleaf验证码生成

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVe<i>本文来源gaodai$ma#com搞$代*码*网</i>rsion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>web</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>web</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <!-- ThymeLeaf 依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

#Thymeleaf配置
spring:
  mvc:
    static-path-pattern: /**
  thymeleaf:
    mode: HTML
    encoding: UTF-8
    #关闭缓存
    cache: false

package com.example.web.controller;

import com.example.web.util.VerifyCode;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

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

@RestController
public class CaptchaController {
    /* 获取验证码图片*/

    @RequestMapping("/getVerifyCode")
    public void getVerificationCode(HttpServletResponse response, HttpServletRequest request) {
        try {
            int width = 200;
            int height = 69;

            BufferedImage verifyImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);//生成对应宽高的初始图片
            String randomText = VerifyCode.drawRandomText(width, height, verifyImg);//单独的一个类方法，出于代码复用考虑，进行了封装。功能是生成验证码字符并加上噪点，干扰线，返回值为验证码字符

            request.getSession().setAttribute("verifyCode", randomText);
            response.setContentType("image/png");//必须设置响应内容类型为图片，否则前台不识别

            OutputStream os = response.getOutputStream(); //获取文件输出流
            ImageIO.write(verifyImg, "png", os);//输出图片流
            os.flush();
            os.close();//关闭流
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}