[文件上传工具类] Thumbnails之上传图片后压缩等处理

目录

1. Thumbnails简介

2. 导入依赖

3. 图片压缩工具类代码

4. 参数介绍

---

1. Thumbnails简介

图像处理API，可以实现图像常用操作(图片信息、扩大、缩小、压缩等)

2. 导入依赖

    commons-fileupload
    commons-fileupload
    1.3.3



    net.coobird
    thumbnailator
    0.4.8

3. 图片压缩工具类代码

package *;

import net.coobird.thumbnailator.Thumbnails;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.commons.CommonsMultipartFile;

import javax.annotation.PostConstruct;
import java.io.*;

/**
 * 压缩工具类
 *
 * @Author pzy
 * @Description: TODO 需要多次测试调整参数
 * @Version 0.1.0
 */
public class CompressionUtils {
    
    private static MultipartFile getMulFileByFile(InputStream fis, String fieldName, String contentType, String fileName) {
        FileItem fileItem = createFileItem(fis, fieldName, contentType, fileName);
        return new CommonsMultipartFile(fileItem);
    }

    private static FileItem createFileItem(InputStream fis, String fieldName, String contentType, String fileName) {
        FileItemFactory factory = new DiskFileItemFactory(16, null);
        FileItem item = factory.createItem(fieldName, contentType, false, fileName);
        int bytesRead = 0;
        byte[] buffer = new byte[8192];
        try {
            OutputStream os = item.getOutputStream();
            while ((bytesRead = fis.read(buffer, 0, 8192)) != -1) {
                os.write(buffer, 0, bytesRead);
            }
            os.close();
            fis.close();

        } catch (IOException e) {
            e.printStackTrace();
        }
        return item;
    }

    public static MultipartFile compressImg(MultipartFile multiFile) {
        // 压缩图片
        InputStream inputStream = null;
        ByteArrayOutputStream bos = null;
        MultipartFile multipartFile = null;
        InputStream fileInput = null;
        try {
            inputStream = multiFile.getInputStream();
            bos = new ByteArrayOutputStream();
            // 压缩图片核心代码
            Thumbnails.Builder builder = Thumbnails.of(inputStream);
            builder
                    .scale(1f) //等比缩放
                    .outputQuality(0.3f) //1高质量 -> 0 低质量
                    .toOutputStream(bos);
            fileInput = new ByteArrayInputStream(bos.toByteArray());
            // 转换 MultipartFile
            String fieldName = multiFile.getName();
            String fileName = multiFile.getOriginalFilename();
            String contentType = multiFile.getContentType();
            multipartFile = getMulFileByFile(fileInput, fieldName, contentType, fileName);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (inputStream != null) {
                    inputStream.close();
                }
                if (bos != null) {
                    bos.close();
                }
                if (fileInput != null) {
                    fileInput.close();
                }
            } catch (IOException e) {
                e.printStackTrace();

            }
        }
        return multipartFile;
    }


}

4. 参数介绍

scale 缩放比例 ：大于1是放大，小于1是缩小

-> 4.1 创建builder对象

Builder bdFile = Thumbnails.of(files.getAbsolutePath())

-> 4.2 方法也可以直接使用

package ;

import net.coobird.thumbnailator.Thumbnails;
import net.coobird.thumbnailator.geometry.Position;


import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Objects;

/**
 * 压缩图片处理的公用方法
 * 理解成注释也行
 * 

 * 

 * linux批处理指令  //find /thumbnail/ -regex '.*\(jpg\|JPG\|png\|PNG\|jpeg\)' -size +49k -exec convert -resize "x300>" -quality 75 {} {} \;
 *
 * @Author pzy
 * @Description: TODO
 * @Version 0.1.0
 */
public class CompressionMethod {

    //代码
    //
    //    net.coobird
    //    thumbnailator
    //    0.4.8
    //


    /**
     * @param scale    缩放比例 ：大于1是放大，小于1是缩小
     * @param fromFile 源图片路径
     * @param tofile   目的图片路径
     * @throws IOException 

     * @Title: scale

     * @Description: 按比例缩放

     */
    public static void scale(double scale, String fromFile, String tofile) throws IOException {
        Thumbnails.of(fromFile).scale(0.5).toFile(tofile);
    }

    /**
     * @param height   图片高 px
     * @param width    图片宽 px
     * @param fromFile
     * @param tofile
     * @throws IOException 

     * @Title: size

     * @Description: 按大小尺寸缩放

     */
    public static void size(int height, int width, String fromFile, String tofile) throws IOException {
        Thumbnails.of(fromFile).size(width, height).toFile(tofile);
    }


    /**
     * @param height   图片缩小高度至 px
     * @param fromFile
     * @param tofile
     * @throws IOException 

     * @Title: height

     * @Description: 按指定高度缩小图片，等比例调整图片宽度

     */
    public static void height(int height, String fromFile, String tofile) throws IOException {
        Thumbnails.of(fromFile).height(height).toFile(tofile);
    }


    /**
     * @param width    图片缩小宽度至 px
     * @param fromFile
     * @param tofile
     * @throws IOException 

     * @Title: width

     * @Description: 按指定宽度缩小图片，等比例调整图片高度

     */
    public static void width(int width, String fromFile, String tofile) throws IOException {
        Thumbnails.of(fromFile).width(width).toFile(tofile);
    }

    /**
     * @param quality  图片质量比例，1 为高质量，越接近0图片质量越低
     * @param fromFile
     * @param tofile
     * @throws IOException 

     * @Title: outputQuality

     * @Description: 设置图片质量，一般与缩放功能同时使用

     */
    public static void outputQuality(float quality, String fromFile, String tofile) throws IOException {
        Thumbnails.of(fromFile).outputQuality(quality).toFile(tofile);
    }

    /**
     * @param position 位置
     * @param image    图片
     * @param opacity  透明度
     * @param fromFile
     * @param tofile
     * @throws IOException 

     * @Title: watermark

     * @Description: 添加图片水印

     */
    public static void watermark(Position position, BufferedImage image, float opacity, String fromFile, String tofile) throws IOException {
        Thumbnails.of(fromFile).watermark(position, image, opacity).toFile(tofile);
    }

    /**
     * @param angle    正数则为顺时针，负数则为逆时针
     * @param fromFile
     * @param tofile
     * @throws IOException 

     * @Title: rotate

     * @Description: 图片旋转 

     */
    public static void rotate(double angle, String fromFile, String tofile) throws IOException {
        Thumbnails.of(fromFile).rotate(angle).toFile(tofile);
    }

    /**
     * @param position 图片位置
     * @param width    裁剪宽
     * @param height   裁剪高
     * @param fromFile
     * @param tofile
     * @throws IOException 

     * @Title: sourceRegion

     * @Description: 裁剪图片

     */
    public static void sourceRegion(Position position, int width, int height, String fromFile, String tofile) throws IOException {
//		Thumbnails.of(fromFile).sourceRegion(Positions.TOP_CENTER, width, height).toFile(tofile);
        Thumbnails.of(fromFile).sourceRegion(position, width, height).toFile(tofile);
    }

    /**
     * @param fromDir
     * @param tofile
     * @throws IOException 

     * @Title: listfiles

     * @Description: 批量处理文件，可与前几个方法结合起来处理

     */
    public static void listfiles(String fromDir, String tofile) throws IOException {
        Thumbnails.of(Objects.requireNonNull(new File(fromDir).listFiles())).toFile(tofile);
    }


}