Java基础 awt Graphics2D 生成矩形图片并向其中画一条直线

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

 

code

package per.jizuiku.gui;

import java.awt.BasicStroke;
import java.awt.Color;
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
     */
    public static void main(String[] args) {
        try {
            getImage();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

    /**
     * 
     * @throws FileNotFoundException
     * @throws IOException
     */
    public static void getImage() throws FileNotFoundException, IOException {
        // 获得图片缓冲区
        int width = 100;
        int height = 50;
        int imageType = BufferedImage.TYPE_INT_BGR;
        BufferedImage myImage = new BufferedImage(width, height, imageType);

        // 获得画笔
        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);

        // 字的颜色 和 背景的颜色 要不一样的
        pen.setColor(Color.blue);

        // 划线
        // 点动成线，线动成面，面动成体
        // 两点肯定一条直线
        int xStart = 5;
        int yStart = 15;
        int xEnd = 60;
        int yEnd = 30;

        // 设置线的宽度
        float lineWidth = 7F;
        pen.setStroke(new BasicStroke(lineWidth));

        pen.drawLine(xStart, yStart, xEnd, yEnd);

        ImageIO.write(myImage, "JPEG", new FileOutputStream("line" + ".jpg"));

    }

}

 

result

 

sourceCode

/**
    * Draws a line, using the current color, between the points
    * <code>(x1,&nbsp;y1)</code> and <code>(x2,&nbsp;y2)</code>
    * in this graphics context's coordinate system.
    * @param   x1  the first point's <i>x</i> coordinate.
    * @param   y1  the first point's <i>y</i> coordinate.
    * @param   x2  the second point's <i>x</i> coordinate.
    * @param   y2  the second point's <i>y</i> coordinate.
    */
public abstract void drawLine(int x1, int y1, int x2, int y2);

 

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

 

---

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。