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不损失清晰度情况对图片进行压缩的工具类(可通过地址也可以通过文件调用)

news 2025/11/10 23:32:03

一、效果

原图和效果图对比

二、工具类代码

2.1导包

 <dependency><groupId>net.coobird</groupId><artifactId>thumbnailator</artifactId><version>0.4.16</version>
</dependency>
<dependency><groupId>commons-fileupload</groupId><artifactId>commons-fileupload</artifactId><version>1.5</version>
</dependency>

注意点:工具类里面有一个地方需要返回MultipartFile类，如果需要这个方法那么就还需要导包，如果不需要，可以直接删除工具类的downloadAndCompressToMultpartFile这个方法

<dependency><groupId>org.springframework</groupId><artifactId>spring-test</artifactId><version>5.3.20</version>
</dependency>

2.2 工具类


import net.coobird.thumbnailator.Thumbnails;
import org.springframework.mock.web.MockMultipartFile;
import org.springframework.web.multipart.MultipartFile;
import org.thymeleaf.util.StringUtils;import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;public class ImageCompressorUtil {/*** 下载并压缩图片（保持高清晰度）*/public static void downloadAndCompress(String imageUrl, String savePath) throws Exception {long startTime = System.currentTimeMillis();try  {InputStream inputStream = getImageInputStream(imageUrl);// 使用Thumbnailator进行高质量压缩Thumbnails.of(inputStream).scale(1.0) // 保持原始尺寸.outputQuality(0.75) // 质量参数（0.0-1.0，值越高质量越好）.toFile(savePath);long originalSize = getRemoteFileSize(imageUrl);long compressedSize = new File(savePath).length();System.out.println("\n处理完成：" + savePath);System.out.println("原图大小：" + formatSize(originalSize));System.out.println("压缩后大小：" + formatSize(compressedSize));System.out.println("耗时：" + (System.currentTimeMillis() - startTime) + "ms");} catch (Exception e) {System.err.println("处理失败：" + e.getMessage());throw e;}}/*** 通过地址压缩图片* @param imageUrl* @param quality 建议0.7* @return* @throws Exception*/public static MultipartFile downloadAndCompressToMultpartFile(String imageUrl, double quality) throws Exception {try  {InputStream inputStream = getImageInputStream(imageUrl);ByteArrayOutputStream outputStream = new ByteArrayOutputStream();// 压缩图片Thumbnails.of(inputStream).scale(1.0).outputQuality(quality).toOutputStream(outputStream);// 提取文件名和内容类型String originalFilename = extractFileName(imageUrl);String contentType = detectContentType(originalFilename);if(StringUtils.isEmpty(contentType)){return null;}// 使用Spring的MockMultipartFile创建实例return new MockMultipartFile("file",                 // 表单字段名originalFilename,       // 原始文件名contentType,            // 内容类型outputStream.toByteArray()  // 文件内容);} catch (Exception e) {System.err.println("处理失败：" + e.getMessage());throw e;}}/*** 从URL提取文件名*/private static String extractFileName(String url) {if (url == null){return null;}int lastSlash = url.lastIndexOf('/');String fileName = lastSlash > 0 ? url.substring(lastSlash + 1) : url;// 处理查询参数（如果有）int queryIndex = fileName.indexOf('?');if (queryIndex > 0) {fileName = fileName.substring(0, queryIndex);}// 如果没有扩展名，默认为jpgif (!fileName.contains(".")) {fileName += ".jpg";}return fileName;}/*** 检测文件内容类型*/private static String detectContentType(String fileName) {if (fileName == null) {return null;}String lowerCaseName = fileName.toLowerCase();if (lowerCaseName.endsWith(".png")) return "image/png";if (lowerCaseName.endsWith(".gif")) return "image/gif";if (lowerCaseName.endsWith(".webp")) return "image/webp";if (lowerCaseName.endsWith(".bmp")) return "image/bmp";return "image/jpeg";}/*** 获取图片输入流（处理网络连接）*/private static InputStream getImageInputStream(String imageUrl) throws IOException {URL url = new URL(imageUrl);HttpURLConnection connection = (HttpURLConnection) url.openConnection();connection.setRequestMethod("GET");connection.setConnectTimeout(5000);connection.setReadTimeout(10000);connection.setRequestProperty("User-Agent", "Mozilla/5.0");if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {throw new IOException("图片下载失败，响应码：" + connection.getResponseCode());}return connection.getInputStream();}public static File compressMultipartFile(MultipartFile file, double quality, String outputPath) throws Exception {if (file == null || file.isEmpty()) {throw new IllegalArgumentException("上传的文件为空");}long startTime = System.currentTimeMillis();File outputFile = new File(outputPath);try {InputStream inputStream = file.getInputStream();// 使用Thumbnailator进行高质量压缩Thumbnails.of(inputStream).scale(1.0).outputQuality(quality).toFile(outputFile);long originalSize = file.getSize();long compressedSize = outputFile.length();System.out.println("\n处理完成：" + outputPath);System.out.println("原图大小：" + formatSize(originalSize));System.out.println("压缩后大小：" + formatSize(compressedSize));System.out.println("耗时：" + (System.currentTimeMillis() - startTime) + "ms");return outputFile;} catch (Exception e) {System.err.println("压缩失败：" + e.getMessage());// 清理可能生成的不完整文件if (outputFile.exists()) {outputFile.delete();}throw e;}}public static InputStream compressToStream(MultipartFile file, double quality) throws Exception {if (file == null || file.isEmpty()) {throw new IllegalArgumentException("上传的文件为空");}ByteArrayOutputStream outputStream = new ByteArrayOutputStream();try {InputStream inputStream = file.getInputStream();// 压缩到输出流Thumbnails.of(inputStream).scale(1.0).outputQuality(quality).toOutputStream(outputStream);// 转换为ByteArrayInputStream以便返回return new ByteArrayInputStream(outputStream.toByteArray());} catch (Exception e) {System.err.println("压缩失败：" + e.getMessage());throw e;}}/*** 获取远程文件大小*/private static long getRemoteFileSize(String imageUrl) {try {URL url = new URL(imageUrl);HttpURLConnection connection = (HttpURLConnection) url.openConnection();connection.setRequestMethod("HEAD");return connection.getContentLength();} catch (Exception e) {return -1;}}/*** 格式化文件大小（B/KB/MB）*/private static String formatSize(long bytes) {if (bytes < 0) {return "未知";}if (bytes < 1024){return bytes + "B";}if(bytes < 1024 * 1024){return String.format("%.2fKB", bytes / 1024.0);}return String.format("%.2fMB", bytes / (1024.0 * 1024));}/*** 调整压缩质量参数（0.0-1.0）* 较高的值（如0.8-0.9）保持更好的质量* 较低的值（如0.6-0.7）实现更高的压缩率*/public static void setCompressionQuality(double quality) {// 验证参数范围if (quality < 0.0 || quality > 1.0) {throw new IllegalArgumentException("质量参数必须在0.0-1.0之间");}// 这里可以添加全局质量参数的存储逻辑}/*** 测试方法*/public static void main(String[] args) throws Exception {// 测试JPG图片压缩String jpgUrl = "https://51fangtao.oss-cn-shenzhen.aliyuncs.com/mall/upload/1687858554984u9acttxm0uuupk6v6ddo.jpg";String jpgSavePath = "D:/compressed_jpg.jpg";downloadAndCompress(jpgUrl, jpgSavePath);// 测试PNG图片压缩（转换为JPG以获得更好的压缩率）String pngUrl = "https://ftimageupload.oss-cn-shenzhen.aliyuncs.com/17029036937294.png";String pngSavePath = "D:/compressed_png.jpg"; // 保存为JPGdownloadAndCompress(pngUrl, pngSavePath);}
}

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