Java使用圖片壓縮工具壓縮圖片的兩種方法
阿新 • • 發佈:2022-05-26
pom.xml
<!--thumbnailator圖片處理--> <dependency> <groupId>net.coobird</groupId> <artifactId>thumbnailator</artifactId> <version>0.4.8</version> </dependency>
工具類
指定大小,不失真,不丟失精度
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,按照阿里程式碼開發規範,不允許程式碼中出現魔法值 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 finalDouble 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; /** * 根據指定大小壓縮圖片 * * @param imageBytes 源圖片位元組陣列 * @param desFileSize 指定圖片大小,單位kb * @return 壓縮質量後的圖片位元組陣列 */ 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("圖片原大小={}kb | 壓縮後大小={}kb", srcSize / ONE_ZERO_TWO_FOUR, imageBytes.length / ONE_ZERO_TWO_FOUR); } catch (Exception e) { logger.error("【圖片壓縮】msg=圖片壓縮失敗!", e); } return imageBytes; } /** * 自動調節精度(經驗數值) * * @param size 源圖片大小 * @return 圖片壓縮質量比 */ 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,不丟失精度,壓縮會有幾百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 { //獲取檔案輸入流 InputStream inputStream = file.getInputStream(); try { // 把圖片讀入到記憶體中 BufferedImage bufImg = ImageIO.read(inputStream); // 壓縮程式碼,儲存圖片檔案byte陣列 ByteArrayOutputStream bos = new ByteArrayOutputStream(); //防止圖片變紅,這一步非常重要 BufferedImage bufferedImage = new BufferedImage(bufImg.getWidth(), bufImg.getHeight(), BufferedImage.TYPE_INT_RGB); bufferedImage.createGraphics().drawImage(bufImg,0,0, Color.WHITE,null); //先轉成jpg格式來壓縮,然後在通過OSS來修改成原始檔本來的字尾格式 ImageIO.write(bufferedImage,"jpg",bos); return bos.toByteArray(); } catch (IOException e) { e.printStackTrace(); }finally { inputStream.close(); } return null; } }
使用測試
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 { //壓縮圖片到指定120K以內,不管你的圖片有多少兆,都不會超過120kb,精度還算可以,不會模糊 byte[] bytes = PicUtils.compressPicForScale(file.getBytes(), 120); //生成儲存在伺服器的圖片名稱,統一修改原字尾名為: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; } }
測試結果:這裡我用的是3M的原圖進行測試