工具类总结(5)-图片验证码工具类

刺骨的言语ヽ痛彻心扉 2022-06-05 12:37 304阅读 0赞

**struts验证码工具类及使用**

import com.sun.image.codec.jpeg.JPEGCodec;
    import com.sun.image.codec.jpeg.JPEGImageEncoder;
    
    import java.awt.*;
    import java.awt.image.BufferedImage;
    import java.io.ByteArrayOutputStream;
    import java.util.Random;
    
    public class ImageUtil { 
        public static byte[] getInstance(int width, int height, int num, String number) throws Exception {
            byte[] codeArr = null;
             /* * 一,绘图 */
            //step1,内存映像对象(画布)
            BufferedImage image =
                    new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    
            //step2,获得画笔
            Graphics g = image.getGraphics();
    
            //step3,给画笔设置颜色
            Random r = new Random();
            g.setColor(new Color(r.nextInt(255), r.nextInt(255), r.nextInt(255)));
    
            //step4,给画布设置背景颜色
            g.fillRect(0, 0, width, height);
    
            //step5,重新给笔设置颜色
            g.setColor(new Color(255, 255, 255));
            g.setFont(new Font(null, Font.ITALIC, height - height / 5));
    
            //step6,将验证码转换成图片
            g.drawString(number, width / 10, height - height / 5);
            //step7,加一些干扰线
            for (int i = 0; i < 8; i++) {
                g.setColor(new Color(r.nextInt(255),
                        r.nextInt(255), r.nextInt(255)));
                g.drawLine(r.nextInt(width), r.nextInt(height),
                        r.nextInt(width), r.nextInt(height));
            }
            /* * 二,压缩图片并输出 */
            //1.字节数组输出流，向字节数组中输出信息
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
    
            //2.压缩图片
            JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(baos);
    
            //图片中的二进制信息输出到内存中
            encoder.encode(image);
    
            codeArr = baos.toByteArray();
    
            return codeArr;
        }
    
    
        //获取随机数
        public static String getNumber(int num) {
            String number = "";
            String chars = "0123456789";
            Random r = new Random();
            for (int i = 0; i < num; i++) {
                number += chars.charAt(
                        r.nextInt(chars.length()));
            }
            return number;
        }
    }

### 使用 ###

#### action ####

import com.mlj.dangdang.util.ImageUtil;
    import com.mlj.dangdang.util.Struts2ScopeUtil;
    import com.opensymphony.xwork2.ActionSupport;
    import org.apache.struts2.ServletActionContext;
    
    import javax.servlet.http.HttpServletResponse;
    import java.io.ByteArrayInputStream;
    import java.io.IOException;
    import java.io.InputStream;
    
    public class ImgcodeAction extends ActionSupport { 
    
        private InputStream inputStream;
        private String number;//验证码
        private String checkImginfo;
    
        public String getCheckImginfo() {
            return checkImginfo;
        }
    
        public void setCheckImginfo(String checkImginfo) {
            this.checkImginfo = checkImginfo;
        }
    
        public String getNumber() {
            return number;
        }
    
        public void setNumber(String number) {
            this.number = number;
        }
    
        public InputStream getInputStream() {
            return inputStream;
        }
    
        public void setInputStream(InputStream inputStream) {
            this.inputStream = inputStream;
        }
    
        /** * 获取验证码 * * @return */
        public String imgCode() {
            String imgcode = ImageUtil.getNumber(4);
            Struts2ScopeUtil.setSessionAttribute("imgCode", imgcode);//验证码
            try {
                byte[] attr = ImageUtil.getInstance(100, 30, 4, imgcode);
                inputStream = new ByteArrayInputStream(attr);
            } catch (Exception e) {
                e.printStackTrace();
            }
            return "success";
        }
    
        /** * 验证验证码 */
        public void checkImg() {
            HttpServletResponse response = ServletActionContext.getResponse();
            response.setCharacterEncoding("UTF-8");
    
            String myCode = Struts2ScopeUtil.getSessionAttribute("imgCode").toString();
            if (myCode.equals(number)) {
                try {
                    response.getWriter().print("1");//验证码正确
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } else {
                try {
                    response.getWriter().print("0");//验证码错误
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

#### struts2.xml ####

<?xml version="1.0" encoding="UTF-8"?>
    
    <!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN" "http://struts.apache.org/dtds/struts-2.3.dtd">
    
    <struts>
        <constant name="struts.devMode" value="true"/>
        <constant name="struts.enable.DynamicMethodInvocation" value="true"/>
    
        <package name="image" extends="struts-default" namespace="/image">
            <action name="imgCode" method="imgCode" class="com.mlj.dangdang.action.ImgcodeAction">
                <result name="success" type="stream">
                    <param name="inputName">inputStream</param>
                </result>
            </action>
            <action name="checkImg" class="com.mlj.dangdang.action.ImgcodeAction" method="checkImg">
    
            </action>
        </package>
    
    </struts>