生成验证码 (包含中文的)

/**

            * 在内存中生成图片（纸），没有设置颜色，画填充的矩形，并且和纸的大小相同，矩形有颜色。

            * 获取笔的对象（设置颜色，设置字段，画字符串，画矩形）

            * 先准备好数据，随机生成4个字符，把字符画到纸上

            * 画干扰线

            * 把内存中的图片输出到客户端上

            */

           

           

            int width=120;

            int height=30;

            //在内存中生成图片

           BufferedImage image= new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB );

            //先获取画笔对象

           Graphics2D g=(Graphics2D)image.getGraphics();

            //设置灰色

           g.setColor(Color. GRAY);

            //填充矩形为灰色

           g.fillRect(0,0,width,height);

           

            //设置颜色

           g.setColor(Color. BLUE);

           g.drawRect(0,0,width-2,height-2);

           

            //准备数据，随机获取4个字符

            //String words="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

           String words = "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 u56e2u5c4bu79bbu8272u8138u7247u79d1u5012u775bu5229u4e16u521au4e14u7531u9001u5207u661fu5bfcu665au8868u591fu6574u8ba4u54cdu96eau6d41u672au573au8be5u5e76u5e95u6df1u523bu5e73u4f1fu5fd9u63d0u786eu8fd1u4eaeu8f7bu8bb2u519cu53e4u9ed1u544au754cu62c9u540du5440u571fu6e05u9633u7167u529eu53f2u6539u5386u8f6cu753bu9020u5634u6b64u6cbbu5317u5fc5u670du96e8u7a7fu5185u8bc6u9a8cu4f20u4e1au83dcu722cu7761u5174u5f62u91cfu54b1u89c2u82e6u4f53u4f17u901au51b2u5408u7834u53cbu5ea6u672fu996du516cu65c1u623fu6781u5357u67aau8bfbu6c99u5c81u7ebfu91ceu575au7a7au6536u7b97u81f3u653fu57ceu52b3u843du94b1u7279u56f4u5f1fu80dcu6559u70edu5c55u5305u6b4cu7c7bu6e10u5f3au6570u4e61u547cu6027u97f3u7b54u54e5u9645u65e7u795eu5ea7u7ae0u5e2eu5566u53d7u7cfbu4ee4u8df3u975eu4f55u725bu53d6u5165u5cb8u6562u6389u5ffdu79cdu88c5u9876u6025u6797u505cu606fu53e5u533au8863u822cu62a5 u53f6u538bu6162u53d4u80ccu7ec6";

           

           String code="";

            //返回指定下标位置的字符，随机获取4个下标

           Random random= new Random();

            int x=20;

            int y=20;

           g.setColor(Color. YELLOW);

            // 设置字体

           g.setFont( new Font( "楷体", Font.BOLD , 20));

            for( int i=0;i<4;i++)

           {

                 // void rotate(double theta , double x, double y) 

                 // theta 弧度

                 // hudu = jiaodu * Math.PI / 180;

                 // 获取正负30之间的角度

                 int jiaodu = random.nextInt(60)-30;

                 double hudu = jiaodu * Math. PI / 180;

                g.rotate(hudu, x, y);

                 // 获取下标

                 int index = random.nextInt(words.length());

                 // 返回指定下标位置的字符，随机获取下标

                 char ch = words.charAt(index);

                 // 写字符串

                g.drawString( ""+ch, x, y);

                

                g.rotate(-hudu, x, y);

                x += 20;

           }

           g.setColor(Color. WHITE);

           

            int x1,x2,y1,y2;

            for( int i=0;i<4;i++)

           {

           x1=random.nextInt(width);

           x2=random.nextInt(width);

           y1=random.nextInt(height);

           y2=random.nextInt(height);

            //画干扰线

           g.drawLine(x1,y1,x2,y2);

           }

            //把内存中的图片输出到浏览器端

          ImageIO. write(image,"jpg",response.getOutputStream());