java graphics2d 画图工具使用

graphics2d api整理（列举一些经常使用的）

• 画板画笔设置

/**
 * 创建画板
 */
 public Graphics2D createGraphics();
/**
 * 渲染效果配置
 */
 public abstract void setRenderingHint(Key hintKey, Object hintValue);
/**
 * 设置画笔颜色
 */
public abstract void setPaint( Paint paint );
/**
 * 设置文字样式
 */
public abstract void setFont(Font font);

• 画图

/**
 * 往画板上填充图片，observer一般设置为null
 */
public abstract boolean drawImage(Image img, int x, int y,
                                      ImageObserver observer);
/**
 * 往画板上写字
 */
public abstract void drawString(String str, int x, int y);
/**
 * 画矩形
 */
public void drawRect(int x, int y, int width, int height);
/**
 * 填充矩形
 */
public abstract void fillRect(int x, int y, int width, int height);
/**
 * 画圆弧 startAngle=90时指向北方，逆时针方向画线
 */
public abstract void drawArc(int x, int y, int width, int height,
                                 int startAngle, int arcAngle);
/**
 * 填充扇形 startAngle=90时指向北方，逆时针方向填充
 */
public abstract void fillArc(int x, int y, int width, int height,
                                 int startAngle, int arcAngle);
/**
 * 画椭圆 width = height时为圆
 */
public abstract void drawOval(int x, int y, int width, int height);
/**
 * 填充椭圆
 */
public abstract void fillOval(int x, int y, int width, int height);

• 画圆案例

public class CircularDemo {

    private static final String STORE_PATH = "/opt/study/result.png";
    private static final String TEMPLATE_PATH = "/opt/study/template.jpeg";

    public static void main(String[] args) throws Exception {

        long start = System.currentTimeMillis();

        BufferedImage image = ImageIO.read(new File(TEMPLATE_PATH));

        // create graphics
        Graphics2D graphics = image.createGraphics();

        // set graphics profile
        graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        graphics.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
        graphics.setRenderingHint(RenderingHints.KEY_INTERPOLATION,RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR);
        graphics.setRenderingHint(RenderingHints.KEY_COLOR_RENDERING,RenderingHints.VALUE_COLOR_RENDER_QUALITY);
        graphics.setRenderingHint(RenderingHints.KEY_ALPHA_INTERPOLATION,RenderingHints.VALUE_ALPHA_INTERPOLATION_QUALITY);

        // draw circular
        graphics.setPaint(Color.BLUE);
        graphics.drawArc(200,200,200,200,90,450-30);
        graphics.fillArc(200,200,200,200,90,450-30);

        // draw sector
        graphics.setPaint(Color.RED);
        graphics.drawArc(200,200,200,200,90-30,30);
        graphics.fillArc(200,200,200,200,90-30,30);


        // store and end
        graphics.dispose();
        ImageIO.write(image, "PNG", new File(STORE_PATH));

        System.out.println(System.currentTimeMillis()-start);

    }
}

template.jpeg

result.png

附录

• 配置font字体时不知道有哪些？先用下面这段代码打印一下所有的字体

public class FontDemo {
    public static void main(String[] args) {
        Font[] fonts = GraphicsEnvironment
                .getLocalGraphicsEnvironment()
                .getAllFonts();
        for (Font font : fonts) {
            System.out.println(font.getFontName());
        }
    }
}