java使用谷歌驗證碼google captcha

 一、引入依賴

compile group: 'com.github.penggle', name: 'kaptcha', version: '2.3.2'      

 二、寫controller,傳回圖檔

import com.google.code.kaptcha.Constants;
import com.google.code.kaptcha.Producer;
import com.google.code.kaptcha.impl.DefaultKaptcha;
import com.google.code.kaptcha.util.Config;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Properties;

/**
 * 驗證碼
 *
 */
@Controller
@RequestMapping("/api/code")
public class VerificationCodeController {
    @Autowired
    private Producer captchaProducer;

    @Bean(name = "captchaProducer")
    public DefaultKaptcha getKaptchaBean() {

        DefaultKaptcha defaultKaptcha = new DefaultKaptcha();
        Properties properties = new Properties();
        properties.setProperty("kaptcha.border", "yes");
        properties.setProperty("kaptcha.border.color", "105,179,90");
        properties.setProperty("kaptcha.textproducer.font.color", "blue");
        properties.setProperty("kaptcha.image.width", "125");
        properties.setProperty("kaptcha.image.height", "45");
        properties.setProperty("kaptcha.session.key", "code");
        properties.setProperty("kaptcha.textproducer.char.length", "4");
        properties.setProperty("kaptcha.textproducer.font.names", "宋體,楷體,微軟雅黑");
        Config config = new Config(properties);
        defaultKaptcha.setConfig(config);
        return defaultKaptcha;
    }


    /**
     * 擷取圖形驗證碼
     */
    @RequestMapping("/getCaptcha")
    public void getCaptcha(HttpServletResponse response, HttpSession session) throws IOException {

        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();

        // store the text in the session
        //request.getSession().setAttribute(Constants.KAPTCHA_SESSION_KEY, capText);
        //将驗證碼存到session
        session.setAttribute(Constants.KAPTCHA_SESSION_KEY, capText);
        // create the image with the text
        BufferedImage bi = captchaProducer.createImage(capText);
        ServletOutputStream out = response.getOutputStream();
        // write the data out
        ImageIO.write(bi, "jpg", out);
        try {
            out.flush();
        } finally {
            out.close();
        }

    }


}