增加内置字体、贝塞尔曲线、算术验证码、base64输出

src/main/java/com/wf/captcha/ChineseCaptcha.java

@@ -38,10 +38,14 @@ public class ChineseCaptcha extends ChineseCaptchaAbstract {
      */
     @Override
     public boolean out(OutputStream out) {
-        checkAlpha();
         return graphicsImage(textChar(), out);
     }
 
+    @Override
+    public String toBase64() {
+        return toBase64("data:image/png;base64,");
+    }
+
     /**
      * 生成验证码图形
      *
@@ -50,54 +54,34 @@ public class ChineseCaptcha extends ChineseCaptchaAbstract {
      * @return boolean
      */
     private boolean graphicsImage(char[] strs, OutputStream out) {
-        boolean ok;
         try {
             BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
-            Graphics2D g = (Graphics2D) bi.getGraphics();
-            AlphaComposite ac3;
-            int len = strs.length;
-            g.setColor(Color.WHITE);
-            g.fillRect(0, 0, width, height);
+            Graphics2D g2d = (Graphics2D) bi.getGraphics();
+            // 填充背景
+            g2d.setColor(Color.WHITE);
+            g2d.fillRect(0, 0, width, height);
             // 抗锯齿
-            g.setColor(color());
-            Font font = getFont();
-            g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
-            int hp = (height - font.getSize()) >> 1;
-            int h = height - hp;
-            int w = width / strs.length;
-            int sp = (w - font.getSize()) / 2;
+            g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+            // 画干扰圆
+            drawOval(3, g2d);
+            // 画干扰线
+            g2d.setStroke(new BasicStroke(1.2f, BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL));
+            drawBesselLine(1, g2d);
             // 画字符串
-            for (int i = 0; i < len; i++) {
-                // 计算坐标
-                int x = i * w + sp + num(-5, 5);
-                int y = h + num(-5, 5);
-                if (x < 5) {
-                    x = 5;
-                }
-                if (x + font.getSize() > width) {
-                    x = width - font.getSize();
-                }
-                if (y > height) {
-                    y = height;
-                }
-                if (y - font.getSize() < 0) {
-                    y = font.getSize();
-                }
-                g.setFont(font.deriveFont(num(2) == 0 ? Font.PLAIN : Font.ITALIC));
-                g.drawString(String.valueOf(strs[i]), x, y);
+            g2d.setFont(getFont());
+            FontMetrics fontMetrics = g2d.getFontMetrics();
+            int fW = width / strs.length;  // 每一个字符所占的宽度
+            int fSp = (fW - (int) fontMetrics.getStringBounds("王", g2d).getWidth()) / 2;  // 字符的左右边距
+            for (int i = 0; i < strs.length; i++) {
+                g2d.setColor(color());
+                int fY = height - ((height - (int) fontMetrics.getStringBounds(String.valueOf(strs[i]), g2d).getHeight()) >> 1);  // 文字的纵坐标
+                g2d.drawString(String.valueOf(strs[i]), i * fW + fSp + 3, fY - 3);
             }
-            // 随机画干扰线
-            g.setStroke(new BasicStroke(1.25f, BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL));
-            ac3 = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.7f);  // 指定透明度
-            g.setComposite(ac3);
-            drawLine(2, g.getColor(), g);
-            // 画干扰圆圈
-            drawOval(5, g.getColor(), g);
+            g2d.dispose();
             ImageIO.write(bi, "png", out);
             out.flush();
-            ok = true;
+            return true;
         } catch (IOException e) {
-            ok = false;
             e.printStackTrace();
         } finally {
             try {
@@ -106,6 +90,6 @@ public class ChineseCaptcha extends ChineseCaptchaAbstract {
                 e.printStackTrace();
             }
         }
-        return ok;
+        return false;
     }
 }