生成图片验证码(VerifyCode)
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package cn.itcast.image; import java.awt.Color; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import javax.imageio.ImageIO; import org.junit.Test; /** * 动态生成图片 * @author HP * */ public class Demo { @Test public void fun() throws FileNotFoundException, IOException{ /** * 1.创建图片缓冲区 * 2.设置其宽高 * 3.得到这个图片的绘制环境(得到画笔) * 4.保存起来 * */ BufferedImage bi = new BufferedImage(70,35,BufferedImage.TYPE_INT_RGB); Graphics g = bi.getGraphics();//得到绘制环境 g.setColor(Color.WHITE);//把环境设置为红色 g.fillRect(0,0,70,35);//填充矩形;从0,0开始,宽70,高35,即整个图片,即为图片设置背景色 g.setColor(Color.RED);//把环境设置为红色 g.drawString("Hello", 2, 35-2);//向图片上写入字符串,其中2,2表示x,y轴的坐标 ImageIO.write(bi, "JPEG",new FileOutputStream("F://xxx.jpg")); } @Test public void fun2() throws FileNotFoundException, IOException{ VerifyCode vc = new VerifyCode(); BufferedImage bi = vc.getImage(); VerifyCode.output(bi,new FileOutputStream("F:/xxx.jpg")); System.out.println(vc.getText()); } }
以上是Demo类,下面我们写VerifyCode类
package cn.itcast.image; import java.awt.BasicStroke; import java.awt.Color; import java.awt.Font; import java.awt.Graphics2D; import java.awt.image.BufferedImage; import java.io.IOException; import java.io.OutputStream; import java.util.Random; import javax.imageio.ImageIO; public class VerifyCode { private int w = 70; private int h = 35; private Random r = new Random(); //("宋体“,”华文楷体“,”黑体“,”华文新魏“,”华文隶书“,”微软雅黑”,“楷体_GB2312") private String[] fontNames = {"宋体","华文楷书","黑体","微软雅黑","楷体_GB2312"}; //可选的字符 private String codes = "23456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; //背景色 private Color bgColor = new Color(255,255,255); //验证码上的文本 private String text; //生成随机的颜色 private Color randomColor(){ int red = r.nextInt(150); int green = r.nextInt(150); int blue = r.nextInt(150); return new Color(red,green,blue); } //生成随机字体 private Font randomFont(){ int index = r.nextInt(fontNames.length); String fontName = fontNames(index); //生成随机的字体名称 int style = r.nextInt(4);//生成随机的样式,0(无样式),1(粗体),2(斜体),3(粗体+斜体) int size = r.nextInt(5)+24;//生成随机字号 24-28 return new Font(fontName,style,size); } private String fontNames(int index) { // TODO Auto-generated method stub return null; } //画干扰线 private void drawLine(BufferedImage image){ int num = 3;//一共画三条 Graphics2D g2 = (Graphics2D)image.getGraphics(); for(int i=0;i<num;i++){//生成两个点的坐标,即4个值 int x1 = r.nextInt(w); int y1 = r.nextInt(h); int x2 = r.nextInt(w); int y2 = r.nextInt(h); g2.setStroke(new BasicStroke(1.5F)); g2.setColor(Color.BLUE);//干扰线是蓝色 g2.drawLine(x1,y1,x2,y2); //划线 } } //随机生成一个字符 private char randomChar(){ int index = r.nextInt(codes.length()); return codes.charAt(index); } private BufferedImage createImage(){ BufferedImage image = new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB); Graphics2D g2 = (Graphics2D)image.getGraphics(); g2.setColor(this.bgColor); g2.fillRect(0, 0, w, h); return image; } //调用这个方法得到验证码 public BufferedImage getImage(){ BufferedImage image = createImage();//创建图片缓冲区 Graphics2D g2 = (Graphics2D) image.getGraphics();//得到绘制环境 StringBuilder sb = new StringBuilder();//用来装载生成的验证文本 //向图片中画4个字符 for(int i= 0;i<4;i++){//循环四次 String s = randomChar()+"";//随机生成一个字符 sb.append(s);//把字母添加到sb中 float x = i*1.0F * w/4;//设置当前字符的x轴坐标 g2.setFont(randomFont());//设置随机字体 g2.setColor(randomColor());//设置随机颜色 g2.drawString(s,x,h-5);//画图 } this.text = sb.toString();//把生成的字符串赋给了this.text drawLine(image);//添加干扰线 return image; } //返回验证码图片上的文本 public String getText(){ return text; } //保存图片到指定的输出流 public static void output(BufferedImage image,OutputStream out) throws IOException{ ImageIO.write(image, "JPEG", out); } }
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