import java.awt.AlphaComposite;

最新推荐文章于 2024-11-09 18:30:00 发布

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#import #null #image #string #exception #file

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本文介绍了一个实用的Java图片处理工具类，包括图片压缩、添加文字和图片水印等功能。通过该工具类，开发者可以轻松地对图片进行压缩、添加文字或图片水印等操作。

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import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;

public final class ImageUtils {

    public final static void pressImage(String pressImg, String targetImg, int x, int y, float alpha) {
        try {
            File img = new File(targetImg);
            Image src = ImageIO.read(img);
            int wideth = src.getWidth(null);
            int height = src.getHeight(null);
            BufferedImage image = new BufferedImage(wideth, height, BufferedImage.TYPE_INT_RGB);
            Graphics2D g = image.createGraphics();
            g.drawImage(src, 0, 0, wideth, height, null);
            //水印文件
            Image src_biao = ImageIO.read(new File(pressImg));
            int wideth_biao = src_biao.getWidth(null);
            int height_biao = src_biao.getHeight(null);
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha));
            g.drawImage(src_biao, x, y, wideth_biao, height_biao, null);
            //水印文件结束
            g.dispose();
            ImageIO.write((BufferedImage) image, "jpg", img);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }


    public static void pressText(String pressText, String targetImg, String fontName, int fontStyle, Color color, int fontSize, int x, int y, float alpha) {
        try {
            File img = new File(targetImg);
            Image src = ImageIO.read(img);
            int width = src.getWidth(null);
            int height = src.getHeight(null);
            BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            Graphics2D g = image.createGraphics();
            g.drawImage(src, 0, 0, width, height, null);
            g.setColor(color);
            g.setFont(new Font(fontName, fontStyle, fontSize));
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha));
            g.drawString(pressText, (width - (getLength(pressText) * fontSize)) / 2 + x, (height - fontSize) / 2 + y);
            g.dispose();
            ImageIO.write((BufferedImage) image, "jpg", img);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }


    public static void resize(String filePath, int height, int width, boolean bb) {
        try {
            double ratio = 0.0; //缩放比例
            File f = new File(filePath);
            BufferedImage bi = ImageIO.read(f);
            Image itemp = bi.getScaledInstance(width, height, bi.SCALE_SMOOTH);
            //计算比例
            if ((bi.getHeight() > height) || (bi.getWidth() > width)) {
                if (bi.getHeight() > bi.getWidth()) {
                    ratio = (new Integer(height)).doubleValue() / bi.getHeight();
                } else {
                    ratio = (new Integer(width)).doubleValue() / bi.getWidth();
                }
                AffineTransformOp op = new AffineTransformOp(AffineTransform.getScaleInstance(ratio, ratio), null);
                itemp = op.filter(bi, null);
            }
            if (bb) {
                BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
                Graphics2D g = image.createGraphics();
                g.setColor(Color.white);
                g.fillRect(0, 0, width, height);
                if (width == itemp.getWidth(null))
                    g.drawImage(itemp, 0, (height - itemp.getHeight(null)) / 2, itemp.getWidth(null), itemp.getHeight(null), Color.white, null);
                else
                    g.drawImage(itemp, (width - itemp.getWidth(null)) / 2, 0, itemp.getWidth(null), itemp.getHeight(null), Color.white, null);
                g.dispose();
                itemp = image;
            }
            ImageIO.write((BufferedImage) itemp, "jpg", f);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) throws IOException {
        pressImage("G://imgtest//sy.jpg", "G://imgtest//test1.jpg", 0, 0, 0.5f);
        pressText("我是文字水印", "G://imgtest//test1.jpg", "黑体", 36, Color.white, 80, 0, 0, 0.3f);
        resize("G://imgtest//test1.jpg", 500, 500, true);
    }

    public static int getLength(String text) {
        int length = 0;
        for (int i = 0; i < text.length(); i++) {
            if (new String(text.charAt(i) + "").getBytes().length > 1) {
                length += 2;
            } else {
                length += 1;
            }
        }
        return length / 2;
    }
}