Java基础 awt Graphics2D 生成矩形图片并向内写入字符串

•     JDK ：OpenJDK-11
•      OS ：CentOS 7.6.1810
•      IDE ：Eclipse 2019‑03
• typesetting ：Markdown

 

code

package per.jizuiku.gui;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import javax.imageio.ImageIO;
/**
 * @author 给最苦
 * @date 2019/06/30
 * @blog www.cnblogs.com/jizuiku
 */
public class Demo {
    /**
     *
     * @param args
     * @throws FileNotFoundException
     * @throws IOException
     */
    public static void main(String[] args) throws FileNotFoundException, IOException {
        // 得到图片缓冲区
        int width = 100;
        int height = 50;
        int imageType = BufferedImage.TYPE_INT_BGR;
        BufferedImage myImage = new BufferedImage(width, height, imageType);
        // 得到画笔
        Graphics2D pen = (Graphics2D)myImage.getGraphics();
        // 设置笔的颜色,即背景色
        pen.setColor(Color.WHITE);
        // 画出一个矩形
        // 坐标x 坐标y 宽度100 长度50
        pen.fillRect(0, 0, 100, 50);
        // monospace 粗体显示 大小12
        Font font = new Font("monospace", Font.BOLD, 25);
        pen.setFont(font);
        // 字的颜色 和 背景的颜色 要不同的
        pen.setColor(Color.blue);
        // 写字
        pen.drawString("abcd", 20, 35);
        ImageIO.write(myImage, "JPEG", new FileOutputStream("abcd.jpg"));
    }
}

 

result

 

sourceCode

/**
    * Renders the text of the specified {@code String}, using the
    * current text attribute state in the {@code Graphics2D} context.
    * The baseline of the
    * first character is at position (<i>x</i>,&nbsp;<i>y</i>) in
    * the User Space.
    * The rendering attributes applied include the {@code Clip},
    * {@code Transform}, {@code Paint}, {@code Font} and
    * {@code Composite} attributes.  For characters in script
    * systems such as Hebrew and Arabic, the glyphs can be rendered from
    * right to left, in which case the coordinate supplied is the
    * location of the leftmost character on the baseline.
    * @param str the string to be rendered
    * @param x the x coordinate of the location where the
    * {@code String} should be rendered
    * @param y the y coordinate of the location where the
    * {@code String} should be rendered
    * @throws NullPointerException if {@code str} is
    *         {@code null}
    * @see         java.awt.Graphics#drawBytes
    * @see         java.awt.Graphics#drawChars
    * @since       1.0
    */
public abstract void drawString(String str, int x, int y);

 

resource

• [ JDK ] openjdk.java.net
• [ doc - 参考 ] docs.oracle.com/en/java/javase/11
• [ 规范 - 推荐 ] yq.aliyun.com/articles/69327
• [ 规范 - 推荐 ] google.github.io/styleguide
• [ 源码 ] hg.openjdk.java.net
• [ OS ] www.centos.org
• [ IDE ] www.eclipse.org/downloads/packages
• [ 平台 ] www.cnblogs.com

 

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感谢帮助过 给最苦 的人们。

Java、Groovy和Scala等基于JVM的语言，优秀，值得学习。

规范的命名和代码格式等，有助于沟通和理解。

JVM的配置、监控与优化，比较实用，值得学习。