新增CaptchaModule模块类

新增一个类 net.wendal.nutzbook.module.CaptchaModule

package net.wendal.nutzbook.module;

import java.awt.image.BufferedImage;

import javax.servlet.http.HttpSession;

import net.wendal.nutzbook.util.Toolkit;

import org.nutz.ioc.loader.annotation.IocBean;
import org.nutz.mvc.annotation.At;
import org.nutz.mvc.annotation.Ok;
import org.nutz.mvc.annotation.Param;

import cn.apiclub.captcha.Captcha;
import cn.apiclub.captcha.backgrounds.GradiatedBackgroundProducer;
import cn.apiclub.captcha.gimpy.FishEyeGimpyRenderer;

@IocBean
@At("/captcha")
public class CaptchaModule {

    @At
    @Ok("raw:png")
    public BufferedImage next(HttpSession session, @Param("w") int w, @Param("h") int h) {
        if (w * h < 1) { //长或宽为0?重置为默认长宽.
            w = 200;
            h = 60;
        }
        Captcha captcha = new Captcha.Builder(w, h)
                                .addText().addBackground(new GradiatedBackgroundProducer())
//                                .addNoise(new StraightLineNoiseProducer()).addBorder()
                                .gimp(new FishEyeGimpyRenderer())
                                .build();
        String text = captcha.getAnswer();
        session.setAttribute(Toolkit.captcha_attr, text);
        return captcha.getImage();
    }
}

关键点

• raw代表RawView
• png是RawView中对image/png的缩写,是数据mime的描述
• 返回值是BufferedImage,且这是image/png, 所以会转为图片显示. 还支持jpg/webp等格式,详情参考RawView的源码吧.
• Captcha有N多的组合和配置,自行选择啦.