Java使用图片压缩工具压缩图片的两种方法
pom.xml
<!--thumbnailator图片处理--> <dependency> <groupId>net.coobird</groupId> <artifactId>thumbnailator</artifactId> <version>0.4.8</version> </dependency>
工具类
指定大小,不失真,不丢失精度
package org.example.util; import net.coobird.thumbnailator.Thumbnails; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.*; /** * @author Gavin.luo * @title: PicUtils * @projectName MyData * @description: * @date 2021/7/20 17:30 */ public class PicUtils { //以下是常量,按照阿里代码开发规范,不允许代码中出现魔法值 private static final Logger logger = LoggerFactory.getLogger(PicUtils.class); private static final Integer ZERO = 0; private static final Integer ONE_ZERO_TWO_FOUR = 1024; private static final Integer NINE_ZERO_ZERO = 900; private static final Integer THREE_TWO_SEVEN_FIVE = 3275; private static final Integer TWO_ZERO_FOUR_SEVEN = 2047; private static final Double ZERO_EIGHT_FIVE = 0.85; private static final Double ZERO_SIX = 0.6; private static final Double ZERO_FOUR_FOUR = 0.44; private static final Double ZERO_FOUR = 0.4; /** * 根据指定大小压缩图片 * * @param imageBytes 源图片字节数组 * @param desFileSize 指定图片大小,单位kb * @return 压缩质量后的图片字节数组 */ public static byte[] compressPicForScale(byte[] imageBytes, long desFileSize) { if (imageBytes == null || imageBytes.length <= ZERO || imageBytes.length < desFileSize * ONE_ZERO_TWO_FOUR) { return imageBytes; } long srcSize = imageBytes.length; double accuracy = getAccuracy(srcSize / ONE_ZERO_TWO_FOUR); try { while (imageBytes.length > desFileSize * ONE_ZERO_TWO_FOUR) { ByteArrayInputStream inputStream = new ByteArrayInputStream(imageBytes); ByteArrayOutputStream outputStream = new ByteArrayOutputStream(imageBytes.length); Thumbnails.of(inputStream) .scale(accuracy) .outputQuality(accuracy) .toOutputStream(outputStream); imageBytes = outputStream.toByteArray(); } logger.info("图片原大小={}kb | 压缩后大小={}kb", srcSize / ONE_ZERO_TWO_FOUR, imageBytes.length / ONE_ZERO_TWO_FOUR); } catch (Exception e) { logger.error("【图片压缩】msg=图片压缩失败!", e); } return imageBytes; } /** * 自动调节精度(经验数值) * * @param size 源图片大小 * @return 图片压缩质量比 */ private static double getAccuracy(long size) { double accuracy; if (size < NINE_ZERO_ZERO) { accuracy = ZERO_EIGHT_FIVE; } else if (size < TWO_ZERO_FOUR_SEVEN) { accuracy = ZERO_SIX; } else if (size < THREE_TWO_SEVEN_FIVE) { accuracy = ZERO_FOUR_FOUR; } else { accuracy = ZERO_FOUR; } return accuracy; } }
不能指定大小,不失真,不丢失精度,压缩会有几百K
package org.example.util; import org.springframework.web.multipart.MultipartFile; import javax.imageio.ImageIO; import java.awt.*; import java.awt.image.BufferedImage; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; /** * @author Gavin.luo * @title: ImgCompression * @projectName MyData * @description: * @date 2021/7/21 14:29 */ public class ImgCompression { public static byte[] getImageCom(MultipartFile file) throws IOException { //获取文件输入流 InputStream inputStream = file.getInputStream(); try { // 把图片读入到内存中 BufferedImage bufImg = ImageIO.read(inputStream); // 压缩代码,存储图片文件byte数组 ByteArrayOutputStream bos = new ByteArrayOutputStream(); //防止图片变红,这一步非常重要 BufferedImage bufferedImage = new BufferedImage(bufImg.getWidth(), bufImg.getHeight(), BufferedImage.TYPE_INT_RGB); bufferedImage.createGraphics().drawImage(bufImg,0,0, Color.WHITE,null); //先转成jpg格式来压缩,然后在通过OSS来修改成源文件本来的后缀格式 ImageIO.write(bufferedImage,"jpg",bos); return bos.toByteArray(); } catch (IOException e) { e.printStackTrace(); }finally { inputStream.close(); } return null; } }
使用测试
package org.example.controller; import org.example.util.ImgCompression; import org.example.util.PicUtils; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.multipart.MultipartFile; import java.io.*; import java.util.UUID; /** * @author Gavin.luo * @title: ImageController * @projectName MyData * @description: * @date 2021/7/21 10:09 */ @RestController @RequestMapping("/image") public class ImageController { @RequestMapping(value = "file/img",method = RequestMethod.POST) public String imgUploads(@RequestParam("file") MultipartFile file) throws IOException { //压缩图片到指定120K以内,不管你的图片有多少兆,都不会超过120kb,精度还算可以,不会模糊 byte[] bytes = PicUtils.compressPicForScale(file.getBytes(), 120); //生成保存在服务器的图片名称,统一修改原后缀名为:jpg String newFileName = UUID.randomUUID() + ".jpg"; File fOut = new File("C:\\image\\copy\\" + newFileName); FileOutputStream fileOutputStream = new FileOutputStream(fOut); fileOutputStream.write(bytes); fileOutputStream.close(); return newFileName; } @RequestMapping(value = "file/img2",method = RequestMethod.POST) public String imgUploads2(@RequestParam("file") MultipartFile file) throws IOException { byte[] bs = ImgCompression.getImageCom(file); String newFileName = UUID.randomUUID() + ".jpg"; File fOut = new File("C:\\image\\copy\\" + newFileName); FileOutputStream fileOutputStream = new FileOutputStream(fOut); fileOutputStream.write(bs); fileOutputStream.close(); return newFileName; } }
测试结果:这里我用的是3M的原图进行测试