生成图片
1.应用一
//测试生成图片
public void test01(){
int width = 100;
int height = 100;
String s = "你好";
File file = new File("D:/image.jpg");
Font font = new Font("Serif", Font.BOLD, 10);
//创建一个画布
BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
//获取画布的画笔
Graphics2D g2 = (Graphics2D)bi.getGraphics();
//开始绘图
g2.setBackground='#'"
g2.clearRect(0, 0, width, height);
g2.setPaint(new Color(0,0,255));
g2.fillRect(0, 0, 100, 10);
g2.setPaint(new Color(253,2,0));
g2.fillRect(0, 10, 100, 10);
g2.setPaint(Color.red);
FontRenderContext context = g2.getFontRenderContext();
Rectangle2D bounds = font.getStringBounds(s, context);
double x = (width - bounds.getWidth()) / 2;
double y = (height - bounds.getHeight()) / 2;
double ascent = -bounds.getY();
double baseY = y + ascent;
//绘制字符串
g2.drawString(s, (int)x, (int)baseY);
try {
//将生成的图片保存为jpg格式的文件。ImageIO支持jpg、png、gif等格式
ImageIO.write(bi, "jpg", file);
} catch (IOException e) {
System.out.println("生成图片出错........");
e.printStackTrace();
}
}
2.应用二：生成背景透明的图片
首先jpg格式的图片，支持RGB，无法实现背景透明
png与gif支持RGB和alpha属性,可以生成透明图片
int width = 400;
int height = 300;
// 创建BufferedImage对象
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
// 获取Graphics2D
Graphics2D g2d = image.createGraphics();
// ---------- 增加下面的代码使得背景透明 -----------------
image = g2d.getDeviceConfiguration().createCompatibleImage(width, height, Transparency.TRANSLUCENT);
g2d.dispose();
g2d = image.createGraphics();
// ---------- 背景透明代码结束 -----------------
// 画图
g2d.setColor(new Color(255,0,0));
g2d.setStroke(new BasicStroke(1));
g2d.draw
//释放对象
g2d.dispose();
// 保存文件
ImageIO.write(image, "png", new File("c:/test.png"));