利用Graphics2D生成圆形中间带五角星的电子签章
package com.wuxian.test;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Transparency;
import java.awt.font.FontRenderContext;
import java.awt.geom.AffineTransform;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.util.Date;
import javax.imageio.ImageIO;
public class UtilsGraphics2D {
private static final int WIDTH = 500;//图片宽度
private static final int HEIGHT = 500;//图片高度
private static String message = "芜羡科技有限公司";
private static String centerName = "测试章";
private static String year = "2018年06月11日";
public static void main(String[] args) throws Exception{
BufferedImage image = startGraphics2D();
try {
String filePath = "D:\\"+new Date().getTime()+".png";
ImageIO.write(image, "png", new File(filePath)); //将其保存在D:\\下，得有这个目录
} catch (Exception ex) {
ex.printStackTrace();
}
}
public static BufferedImage startGraphics2D(){
// 定义图像buffer
BufferedImage buffImg = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
Graphics2D g = buffImg.createGraphics();
// 增加下面代码使得背景透明
buffImg = g.getDeviceConfiguration().createCompatibleImage(WIDTH, HEIGHT, Transparency.TRANSLUCENT);
g.dispose();
g = buffImg.createGraphics();
// 背景透明代码结束
g.setColor(Color.RED);
//设置锯齿圆滑
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
//绘制圆
int radius = HEIGHT/3;//周半径
int CENTERX = WIDTH/2;//画图所出位置
int CENTERY = HEIGHT/2;//画图所处位置
Ellipse2D circle = new Ellipse2D.Double();
circle.setFrameFromCenter(CENTERX, CENTERY, CENTERX + radius, CENTERY + radius);
g.setStroke(new BasicStroke(10));//设置圆的宽度
g.draw(circle);
//绘制中间的五角星
g.setFont(new Font("宋体", Font.BOLD, 120));
g.drawString("★", CENTERX-(120/2), CENTERY+(120/3));
//添加姓名
g.setFont(new Font("宋体", Font.LAYOUT_LEFT_TO_RIGHT, 30));// 写入签名
g.drawString(centerName, CENTERX -(40), CENTERY +(30+50));
//添加年份
g.setFont(new Font("宋体", Font.LAYOUT_LEFT_TO_RIGHT, 20));// 写入签名
g.drawString(year, CENTERX -(60), CENTERY +(30+80));
//根据输入字符串得到字符数组
String[] messages2 = message.split("",0);
String[] messages = new String[messages2.length-1];
System.arraycopy(messages2,1,messages,0,messages2.length-1);
//输入的字数
int ilength = messages.length;
//设置字体属性
int fontsize = 40;
Font f = new Font("Serif", Font.BOLD, fontsize);
FontRenderContext context = g.getFontRenderContext();
Rectangle2D bounds = f.getStringBounds(message, context);
//字符宽度＝字符串长度/字符数
double char_interval = (bounds.getWidth() / ilength);
//上坡度
double ascent = -bounds.getY();
int first = 0,second = 0;
boolean odd = false;
if (ilength%2 == 1)
{
first = (ilength-1)/2;
odd = true;
}
else
{
first = (ilength)/2-1;
second = (ilength)/2;
odd = false;
}
double radius2 = radius - ascent;
double x0 = CENTERX;
double y0 = CENTERY - radius + ascent;
//旋转角度
double a = 2*Math.asin(char_interval/(2*radius2));
if (odd)
{
g.setFont(f);
g.drawString(messages[first], (float)(x0 - char_interval/2), (float)y0);
//中心点的右边
for (int i=first+1;i<ilength;i++)
{
double aa = (i - first) * a;
double ax = radius2 * Math.sin(aa);
double ay = radius2 - radius2 * Math.cos(aa);
AffineTransform transform = AffineTransform.getRotateInstance(aa);//,x0 + ax, y0 + ay);
Font f2 = f.deriveFont(transform);
g.setFont(f2);
g.drawString(messages[i], (float)(x0 + ax - char_interval/2* Math.cos(aa)), (float)(y0 + ay - char_interval/2* Math.sin(aa)));
}
//中心点的左边
for (int i=first-1;i>-1;i--)
{
double aa = (first - i) * a;
double ax = radius2 * Math.sin(aa);
double ay = radius2 - radius2 * Math.cos(aa);
AffineTransform transform = AffineTransform.getRotateInstance(-aa);//,x0 + ax, y0 + ay);
Font f2 = f.deriveFont(transform);
g.setFont(f2);
g.drawString(messages[i], (float)(x0 - ax - char_interval/2* Math.cos(aa)), (float)(y0 + ay + char_interval/2* Math.sin(aa)));
}
}
else
{
//中心点的右边
for (int i=second;i<ilength;i++)
{
double aa = (i - second + 0.5) * a;
double ax = radius2 * Math.sin(aa);
double ay = radius2 - radius2 * Math.cos(aa);
AffineTransform transform = AffineTransform.getRotateInstance(aa);//,x0 + ax, y0 + ay);
Font f2 = f.deriveFont(transform);
g.setFont(f2);
g.drawString(messages[i], (float)(x0 + ax - char_interval/2* Math.cos(aa)), (float)(y0 + ay - char_interval/2* Math.sin(aa)));
}
//中心点的左边
for (int i=first;i>-1;i--)
{
double aa = (first - i + 0.5) * a;
double ax = radius2 * Math.sin(aa);
double ay = radius2 - radius2 * Math.cos(aa);
AffineTransform transform = AffineTransform.getRotateInstance(-aa);//,x0 + ax, y0 + ay);
Font f2 = f.deriveFont(transform);
g.setFont(f2);
g.drawString(messages[i], (float)(x0 - ax - char_interval/2* Math.cos(aa)), (float)(y0 + ay + char_interval/2* Math.sin(aa)));
}
}
return buffImg;
}
}
效果图：
