java fastdfs集成图片压缩与水印

上篇我们讲了文件的上传，一般图片上传都会有压缩图，并且有水印，防止图片被非法使用，这篇我们就讲图片的压缩与添加水印。网上很多压缩与添加水印的工具，我们使用thumbnailator。

添加相关依赖

    <!--使用thumbnailator依赖包(图片压缩)-->
        <dependency>
            <groupId>net.coobird</groupId>
            <artifactId>thumbnailator</artifactId>
            <version>0.4.2</version>
        </dependency>

简单的图片压缩

//size(宽度, 高度)  

/* 
 * 若图片横比200小，高比300小，不变 
 * 若图片横比200小，高比300大，高缩小到300，图片比例不变 
 * 若图片横比200大，高比300小，横缩小到200，图片比例不变 
 * 若图片横比200大，高比300大，图片按比例缩小，横为200或高为300 
 */  
Thumbnails.of("images/a380_1280x1024.jpg")  
    .size(200, 300)  
    .toFile("c:/a380_200x300.jpg");  

Thumbnails.of("images/a380_1280x1024.jpg")  
    .size(2560, 2048)  
    .toFile("c:/a380_2560x2048.jpg");  

简单的添加水印

//watermark(位置，水印图，透明度)  
Thumbnails.of("images/a380_1280x1024.jpg")  
    .size(1280,1024)  
    .watermark(Positions.BOTTOM_RIGHT,ImageIO.read(newFile("images/watermark.png")),0.5f)  
    .outputQuality(0.8f)  
    .toFile("c:/a380_watermark_bottom_right.jpg");  

Thumbnails.of("images/a380_1280x1024.jpg")  
    .size(1280,1024)  
    .watermark(Positions.CENTER,ImageIO.read(newFile("images/watermark.png")),0.5f)  
    .outputQuality(0.8f)  
    .toFile("c:/a380_watermark_center.jpg");  

公司使用的是fastdfs，因此没有实体图片，会稍微复杂一些，接上篇，图片上传工具类就是把上篇的图片上传代码封装为一个工具类，同时图片压缩需要一个图片实体，因此这里是直接在根目录生成，压缩与添加水印后删除，代码如下：

package com.qivay.util;

import net.coobird.thumbnailator.Thumbnails;
import net.coobird.thumbnailator.geometry.Positions;
import org.springframework.web.multipart.MultipartFile;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.HashMap;
import java.util.Map;

/**
 * Created by Administrator on 2017-11-07.
 * 图片压缩工具类
 */
public class ImageCompressUtil {

    /**
     * 图片压缩
     * @param bytes 文件转换的字节流
     * @param name  文件名
     * @param width 压缩后宽度
     * @param helper    图片上传工具类
     * @param needWatermark 是否需要水印
     * @return
     * @throws Exception
     */
    public static String[] compress(byte[] bytes, String name, int width, FastDFSHelper helper, boolean needWatermark) throws Exception {
        File directory = new File("");//参数为空
        String courseFile = directory.getCanonicalPath();
        File file = new File(courseFile, name);
        OutputStream output = new FileOutputStream(file);

        BufferedOutputStream bufferedOutput = new BufferedOutputStream(output);

        bufferedOutput.write(bytes);
        bufferedOutput.close();
        output.close();


        //获取原图的高和宽
        int imgWidth = getImgWidth(file);
        int imgHeight = getImgHeight(file);

        //设置对应的高度
        int height = width * imgHeight / imgWidth;
        int index = name.lastIndexOf(".");
        String suffix = name.substring(index);
        String fileName = UUIDHelper.GetUUID() + suffix;

        File newFile = new File(courseFile, fileName);
        //设置水印
        String compressImage = setWatermark(needWatermark, courseFile, width, height, file, newFile, helper);
        String normalImage = "";
        if (needWatermark) {
            String normalName = UUIDHelper.GetUUID() + suffix;
            File normalFile = new File(courseFile, normalName);
            normalImage = setWatermark(needWatermark, courseFile, getImgWidth(file), getImgHeight(file), file, normalFile, helper);
            normalFile.delete();
        } else {
            normalImage = getFastdfsUrl(file, helper);
        }


        newFile.delete();

        file.delete();
        return new String[]{normalImage, compressImage};
    }


    /**
     * 设置水印
     */
    private static String setWatermark(boolean needWatermark, String courseFile, int width, int height, File file, File newFile, FastDFSHelper helper) throws Exception {
        if (needWatermark) {
            //获取水印图
            File path = new File(ImageCompressUtil.class.getResource("/static/image/qivay.png").getPath());
            File watermark = new File(path.getPath());
            double watermarkWidth = getImgWidth(watermark);
            double watermarkHeight = getImgHeight(watermark);
            //获取同样3/4大小的水印图
            File newWatermark = new File(courseFile, "qivay.png");
            double proportion = watermarkWidth / watermarkHeight;
            watermarkWidth = width * 3 / 4;
            watermarkHeight = new Double(watermarkWidth / proportion).intValue();
            if (height * 3 / 4 < watermarkHeight) {
                watermarkHeight = height * 3 / 4;
                watermarkWidth = new Double(watermarkHeight * proportion).intValue();
            }
            Thumbnails.of(watermark.getPath())
                    .forceSize(new Double(watermarkWidth).intValue(), new Double(watermarkHeight).intValue())
                    .outputQuality(ConstantUtil.IMAGE_MULTIPLE)
                    .toFile(newWatermark.getPath());

            Thumbnails.of(file.getPath())
                    .forceSize(width, height)
                    .watermark(Positions.CENTER, ImageIO.read(newWatermark), 0.5f)
                    .outputQuality(ConstantUtil.IMAGE_MULTIPLE)
                    .toFile(newFile.getPath());
            newWatermark.delete();
        } else {
            Thumbnails.of(file.getPath())
                    .forceSize(width, height)
                    .outputQuality(ConstantUtil.IMAGE_MULTIPLE)
                    .toFile(newFile.getPath());
        }
        return getFastdfsUrl(newFile, helper);
    }

    /**
     * 获取图片上传到fastdfs上的url
     *
     * @param newFile
     * @param helper
     * @return
     * @throws IOException
     */
    private static String getFastdfsUrl(File newFile, FastDFSHelper helper) throws IOException {
        StringBuilder sb = new StringBuilder();
        String[] ids = null;
        FileInputStream fileInputStream = new FileInputStream(newFile);
        byte[] fileBytes = helper.inputStreamToBytes(fileInputStream);
        ids = helper.upload(fileBytes, newFile.getName());
        if (ids.length == 2) {
            sb.append("/" + ids[0] + "/");
            sb.append(ids[1]);
        }
        fileInputStream.close();
        return sb.toString();
    }


    /**
     * 压缩图片，根据上传得到的文件
     *
     * @param mf
     * @param width
     * @param helper
     * @return
     * @throws Exception
     */
    public static String[] compressFile(MultipartFile mf, int width, FastDFSHelper helper, boolean needWatermark) throws Exception {
        byte[] bytes = mf.getBytes();
        return compress(bytes, mf.getOriginalFilename(), width, helper, needWatermark);
    }

    /**
     * 获取图片宽度
     *
     * @param file 图片文件
     * @return 宽度
     */
    public static int getImgWidth(File file) {
        InputStream is = null;
        BufferedImage src = null;
        int ret = -1;
        try {
            is = new FileInputStream(file);
            src = ImageIO.read(is);
            ret = src.getWidth(); // 得到原图宽
            is.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return ret;
    }


    /**
     * 获取图片高度
     *
     * @param file 图片文件
     * @return 高度
     */
    public static int getImgHeight(File file) {
        InputStream is = null;
        BufferedImage src = null;
        int ret = -1;
        try {
            is = new FileInputStream(file);
            src = javax.imageio.ImageIO.read(is);
            ret = src.getHeight(); // 得到源图高
            is.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return ret;
    }


}

更多thumbnailator应用https://www.xuebuyuan.com/3229489.html。