java 编辑图片（压缩文件、加水印）

package com.example.controller.demo;

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 java.lang.annotation.Target;

import javax.imageio.ImageIO;


/**
 * 添加图片水印工具类
 */
public class WaterMarkUtils {
    /**
     * 获取水印地址
     * @return
     */
    private static String getWaterMarkPath(){
        String path=Thread.currentThread().getContextClassLoader().getResource("watermark/water.png").getPath();
        return path;
    }

    /**
     * 图片格式：JPG
     */
    private static final String PICTRUE_FORMATE_JPG = "png";
    private static final String TARGETIMGPATH = "C:\\Users\\lwz\\Desktop\\temp.png";
    //    private static final String DISTPATH = "C:\\Users\\lwz\\Desktop\\temp\\temp.png";
    private static final String WATERIMGPATH = "C:\\Users\\0\\Desktop\\img\\water.png";

    private WaterMarkUtils() {
    }

    /**
     * 添加图片水印
     * @param //targetImg 目标图片路径，如：C://myPictrue//1.jpg
     * @param //waterImg 水印图片路径，如：C://myPictrue//logo.png
     * @param x 水印图片距离目标图片左侧的偏移量，如果x<0, 则在正中间
     * @param y 水印图片距离目标图片上侧的偏移量，如果y<0, 则在正中间
     * @param alpha 透明度(0.0 -- 1.0, 0.0为完全透明，1.0为完全不透明)
     */
    public final static void pressImage(String filePath, int x, int y, float alpha) {

        String imgType = filePath.substring(filePath.lastIndexOf(".")+1,filePath.length());
        try {
            File targetFile = new File(filePath);
            Image image = ImageIO.read(targetFile);
            int width = image.getWidth(null);
            int height = image.getHeight(null);
            BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            Graphics2D g = bufferedImage.createGraphics();
            g.drawImage(image, 0, 0, width, height, null);

            File file = new File(getWaterMarkPath());
            if(file == null){
                return;
            }
            Image waterImage = ImageIO.read(file);	// 水印文件
            int width_1 = waterImage.getWidth(null);
            int height_1 = waterImage.getHeight(null);
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha));

            int widthDiff = width - width_1;
            int heightDiff = height - height_1;
            if(x < 0){
                x = widthDiff / 2;
            }else if(x > widthDiff){
                x = widthDiff;
            }
            if(y < 0){
                y = heightDiff / 2;
            }else if(y > heightDiff){
                y = heightDiff;
            }
            g.drawImage(waterImage, x, y, width_1, height_1, null); // 水印文件结束
            g.dispose();
            ImageIO.write(bufferedImage, imgType, targetFile);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 添加文字水印
     *
     * @param targetImg 目标图片路径，如：C://myPictrue//1.jpg
     * @param pressText 水印文字， 如：中国证券网
     * @param fontName  字体名称，	如：宋体
     * @param fontStyle 字体样式，如：粗体和斜体(Font.BOLD|Font.ITALIC)
     * @param fontSize  字体大小，单位为像素
     * @param color     字体颜色
     * @param x         水印文字距离目标图片左侧的偏移量，如果x<0, 则在正中间
     * @param y         水印文字距离目标图片上侧的偏移量，如果y<0, 则在正中间
     * @param alpha     透明度(0.0 -- 1.0, 0.0为完全透明，1.0为完全不透明)
     */
    public static void pressText(String targetImg, String pressText, String fontName, int fontStyle, int fontSize, Color color, int x, int y, float alpha) {
        try {
            File file = new File(targetImg);

            Image image = ImageIO.read(file);
            int width = image.getWidth(null);
            int height = image.getHeight(null);
            BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            Graphics2D g = bufferedImage.createGraphics();
            g.drawImage(image, 0, 0, width, height, null);
            g.setFont(new Font(fontName, fontStyle, fontSize));
            g.setColor(color);
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha));

            int width_1 = fontSize * getLength(pressText);
            int height_1 = fontSize;
            int widthDiff = width - width_1;
            int heightDiff = height - height_1;
            if (x < 0) {
                x = widthDiff / 2;
            } else if (x > widthDiff) {
                x = widthDiff;
            }
            if (y < 0) {
                y = heightDiff / 2;
            } else if (y > heightDiff) {
                y = heightDiff;
            }

            g.drawString(pressText, x, y + height_1);
            g.dispose();
            ImageIO.write(bufferedImage, PICTRUE_FORMATE_JPG, file);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 获取字符长度，一个汉字作为 1 个字符, 一个英文字母作为 0.5 个字符
     *
     * @param text
     * @return 字符长度，如：text="中国",返回 2；text="test",返回 2；text="中国ABC",返回 4.
     */
    public static int getLength(String text) {
        int textLength = text.length();
        int length = textLength;
        for (int i = 0; i < textLength; i++) {
            if (String.valueOf(text.charAt(i)).getBytes().length > 1) {
                length++;
            }
        }
        return (length % 2 == 0) ? length / 2 : length / 2 + 1;
    }

    /**
     * 图片缩放
     *
     * @param filePath 图片路径
     * @param ratio    指定比例缩放图片
     */
    public static void resize(String filePath, Double ratio) {
        try {
            File file = new File(filePath);
            BufferedImage bi = ImageIO.read(file);
            int fileWidth = bi.getWidth();
            int fileHeight = bi.getHeight();
            resize(filePath, (int) (fileWidth * ratio), (int) (fileHeight * ratio), false);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 图片缩放
     *
     * @param filePath 图片路径
     * @param width    指定宽度缩放图片
     * @param height   指定高度缩放图片
     */
    public static void resize(String filePath, int width, int height) {
        resize(filePath, width, height, false);
    }

    /**
     * 图片缩放
     *
     * @param filePath 图片路径
     * @param height   高度
     * @param width    宽度
     * @param bb       比例不对时是否需要补白
     */
    public static void resize(String filePath, int width, int height, boolean bb) {
        String formatName = filePath.substring(filePath.lastIndexOf(".") + 1, filePath.length());
        try {
            double ratio = 0d; //缩放比例
            File f = new File(filePath);
            BufferedImage bi = ImageIO.read(f);
            Image imageItem = bi.getScaledInstance(width, height, BufferedImage.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);
                imageItem = 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 == imageItem.getWidth(null)) {
                    g.drawImage(imageItem, 0, (height - imageItem.getHeight(null)) / 2, imageItem.getWidth(null), imageItem.getHeight(null), Color.white, null);
                } else {
                    g.drawImage(imageItem, (width - imageItem.getWidth(null)) / 2, 0, imageItem.getWidth(null), imageItem.getHeight(null), Color.white, null);
                }
                g.dispose();
                imageItem = image;
            }
            ImageIO.write((BufferedImage) imageItem, formatName, f);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        try{
           String filePath = "";
           pressImage(filePath,-1,-1,0.6f);
        }catch (Exception ex){
            System.out.println(ex.getMessage());
        }
        pressImage("C://pic//jpg", 5000, 5000, 0f);
        pressText("C://pic//jpg", "旺仔之印", "宋体", Font.BOLD|Font.ITALIC, 20, Color.BLACK, 0, 0, 8f);
        resize("C://pic//4.jpg", 1000, 500, true);
        resize(TARGETIMGPATH, 1366, 736);
    }
}