工具类代码

package com.example.util;import org.apache.commons.io.FileUtils;import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;/*** 文件相关工具类*/
public class FileUtil {/*** 获取网络文件的大小* @param fileUrl* @return*/public static int getFileSize(String fileUrl) {if (fileUrl == null || "".equals(fileUrl)) {return 0;}int fileSize = 0;URL url = null;URLConnection conn = null;try {url = new URL(fileUrl);} catch (MalformedURLException e) {e.printStackTrace();}if (url != null) {try {conn = url.openConnection();} catch (IOException e) {e.printStackTrace();}}if (conn != null) {fileSize = conn.getContentLength();}return fileSize;}
}

测试示例

package com.example.util;import org.junit.jupiter.api.Test;import static org.junit.jupiter.api.Assertions.*;class FileUtilTest {@Testvoid getFileSize() {String fileUrl = "https://pdf.dfcfw.com/pdf/H3_AP202402221622830899_1.pdf?1708673604000.pdf";int fileSize = FileUtil.getFileSize(fileUrl);System.out.println(fileSize); // 435324 == 425 KB}
}

参考文章

• Java获取HTTP网络资源文件大小（带单位）