技術標籤：Java 相關canvasjava 繪製海報

package tools.io;

import lombok.AllArgsConstructor;
import lombok.Getter;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;
import java.io.*;
import java.net.URL;
import java.util.Objects;

/**
 * @author Created by 譚健 on 2021/1/11. 星期一. 17:43.
 * © All Rights Reserved.
 */
 

public class CustomSketchpadUtils {

  /**
   * 圖片座標
   */
  @Getter
  private static class ImagePosition {
    private final int x;
    private final int y;
    private final BufferedImage bufferedImage;

    private int width;
    private int height;

    public ImagePosition(int x, int y, BufferedImage bufferedImage)
 
 {
      this.x = x;
      this.y = y;
      this.bufferedImage = bufferedImage;
    }

    /**
     * 設定圖片繪製為原樣繪製
     */
    public ImagePosition withDefaultHeightAndWidth() {
      this.width = bufferedImage.getWidth();
      this.height = bufferedImage.getHeight();
      return this;
    }

    /**
     * 繪製圖片為自定義大小繪製
     */
 

    public ImagePosition withResetHeightAndWidth(int width, int height) {
      this.width = width;
      this.height = height;
      return this;
    }
  }


  /**
   * 建立一個圖片座標
   *
   * @param x             x
   * @param y             y
   * @param bufferedImage 圖片
   * @return
   */
  public static ImagePosition createImagePosition(int x, int y, BufferedImage bufferedImage) {
    return new ImagePosition(x, y, bufferedImage);
  }


  /**
   * 文字座標
   */
  @AllArgsConstructor
  @Getter
  private static class TextPosition {
    private int x;
    private final int y;
    private final Color color;
    private final Font font;
    private String text;

    /**
     * @param max 最大文字數量
     * @return
     */
    public TextPosition maxLength(int max) {
      int length = text.length();
      if (max < length) {
        this.text = this.text.substring(0, max);
      }
      return this;
    }

    public TextPosition center(int canvasWidth) {
      this.x = canvasWidth / 2 - this.text.length() * 9;
      return this;
    }
  }

  /**
   * 建立一個文字座標
   *
   * @param x     x
   * @param y     y
   * @param text  文字
   * @param color 顏色
   * @param font  字型
   * @return
   */
  public static TextPosition createTextPosition(int x, int y, Color color, Font font, String text) {
    return new TextPosition(x, y, color, font, text);
  }


  /**
   * 讀取圖片到緩衝
   *
   * @param imgUrl 背景地址
   */
  public static BufferedImage readImg(String imgUrl) {
    try {
      return ImageIO.read(new URL(imgUrl));
    } catch (IOException e) {
      e.printStackTrace();
    }
    throw new NullPointerException("圖片讀取失敗");
  }

  /**
   * 建立指定大小的畫布
   *
   * @param width  寬度
   * @param height 高度
   * @return
   */
  public static BufferedImage createCanvas(int width, int height) {
    return new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
  }


  /**
   * 建立一個帶背景的畫布(平鋪模式)
   *
   * @param url 圖片地址
   * @return
   */
  public static BufferedImage createCanvas(String url) {
    BufferedImage background = readImg(url);
    BufferedImage canvas = new BufferedImage(background.getWidth(), background.getHeight(), BufferedImage.TYPE_4BYTE_ABGR);
    drawImage((Graphics2D) canvas.getGraphics(), createImagePosition(0, 0, background).withDefaultHeightAndWidth());
    return canvas;
  }


  /**
   * 建立一個帶背景的畫布(圓角平鋪模式)
   *
   * @param url 圖片地址
   * @return
   */
  public static BufferedImage createFilletCanvas(String url) {
    BufferedImage background = readImg(url);
    int width = background.getWidth();
    int height = background.getHeight();
    // 透明底的圖片
    BufferedImage canvas = new BufferedImage(width, height, BufferedImage.TYPE_4BYTE_ABGR);
    setFillet(background, width, height, canvas);
    return canvas;
  }

  public static void setFillet(BufferedImage background, int width, int height, BufferedImage canvas) {
    Graphics2D graphics2D = canvas.createGraphics();
    graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    int border = 1;

    int resetWidth = width - border * 2;
    int resetHeight = height - border * 2;
    Ellipse2D.Double shape = new Ellipse2D.Double(border, border, resetWidth, resetHeight);
    graphics2D.setClip(shape);
    drawImage(graphics2D, createImagePosition(border, border, background).withResetHeightAndWidth(resetWidth, resetHeight));
    graphics2D.dispose();

    graphics2D = canvas.createGraphics();
    graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    border = 4;
    Stroke s = new BasicStroke(1.5F, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);
    graphics2D.setStroke(s);
    graphics2D.setColor(Color.WHITE);
    graphics2D.drawOval(border, border, width - border * 2, width - border * 2);
    graphics2D.dispose();
  }


  /**
   * 繪製一個文字
   *
   * @param graphics2D 畫板
   * @param text       文字座標
   */
  public static void drawString(Graphics2D graphics2D, TextPosition text) {
    graphics2D.setColor(text.getColor());
    graphics2D.setFont(text.getFont());
    graphics2D.drawString(text.getText(), text.getX(), text.getY());
  }

  /**
   * 繪製一個圖片
   *
   * @param graphics2D 畫板
   * @param image      圖片
   */
  @SuppressWarnings("all")
  public static void drawImage(Graphics2D graphics2D, ImagePosition image) {
    BufferedImage bufferedImage = image.getBufferedImage();
    if (Objects.isNull(image.getWidth()) || Objects.isNull(image.getHeight())) {
      image.withDefaultHeightAndWidth();
    }
    Image scaledInstance = bufferedImage.getScaledInstance(image.getWidth(), image.getHeight(), Image.SCALE_DEFAULT);
    graphics2D.drawImage(scaledInstance, image.getX(), image.getY(), null);
  }


  private static InputStream write2InputStream(BufferedImage canvas) {
    ByteArrayOutputStream os = new ByteArrayOutputStream();
    try {
      ImageIO.write(canvas, "png", os);
    } catch (IOException e) {
      e.printStackTrace();
    }
    return new ByteArrayInputStream(os.toByteArray());
  }


  public static void write2Localhost(BufferedImage canvas, String path) {
    try {
      ImageIO.write(canvas, "png", new FileOutputStream(path));
    } catch (IOException e) {
      e.printStackTrace();
    }
  }


}