Apache common提供了很多实用的工具包，下面就说一下如何用compress包来压缩文件夹。先引入compress，io和lang3这3个工具包：

 <dependencies><dependency><groupId>org.apache.commons</groupId><artifactId>commons-compress</artifactId><version>1.9</version></dependency><dependency><groupId>commons-io</groupId><artifactId>commons-io</artifactId><version>2.4</version></dependency><dependency><groupId>org.apache.commons</groupId><artifactId>commons-lang3</artifactId><version>3.8</version></dependency></dependencies>

这个方法实现了将文件夹下所有的文件压缩成zip包，并输出到文件流中，可以直接写入到文件或提供给前端下载，工具类如下：

import org.apache.commons.compress.archivers.ArchiveException;
import org.apache.commons.compress.archivers.ArchiveStreamFactory;
import org.apache.commons.compress.archivers.zip.Zip64Mode;
import org.apache.commons.compress.archivers.zip.ZipArchiveEntry;
import org.apache.commons.compress.archivers.zip.ZipArchiveOutputStream;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.apache.commons.io.filefilter.TrueFileFilter;
import org.apache.commons.lang3.StringUtils;import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Collection;public class ZipUtils {/*** 压缩文件夹下的所有文件* @param dir          要压缩的文件夹* @param outputStream 输出压缩后的文件流* @throws IOException      IO异常* @throws ArchiveException 压缩异常*/public static void zip(File dir, OutputStream outputStream) throws IOException, ArchiveException {ZipArchiveOutputStream zipOutput = null;try {zipOutput = (ZipArchiveOutputStream) new ArchiveStreamFactory().createArchiveOutputStream(ArchiveStreamFactory.ZIP, outputStream);zipOutput.setEncoding("utf-8");zipOutput.setUseZip64(Zip64Mode.AsNeeded);Collection<File> files = FileUtils.listFilesAndDirs(dir, TrueFileFilter.INSTANCE, TrueFileFilter.INSTANCE);for (File file : files) {InputStream in = null;try {if (file.getPath().equals(dir.getPath())) {continue;}String relativePath = StringUtils.replace(file.getPath(), dir.getPath() + File.separator, "");ZipArchiveEntry entry = new ZipArchiveEntry(file, relativePath);zipOutput.putArchiveEntry(entry);if (file.isDirectory()) {zipOutput.closeArchiveEntry();continue;}in = new FileInputStream(file);IOUtils.copy(in, zipOutput);zipOutput.closeArchiveEntry();} finally {if (in != null) {IOUtils.closeQuietly(in);}}}zipOutput.finish();} finally {IOUtils.closeQuietly(zipOutput);}}public static void main(String args[]) throws IOException, ArchiveException {//要压缩的文件路径File dir = new File("C:\\data\\data");//压缩后zip包文件路径File dest = new File("C:\\data\\test.zip");OutputStream outputStream = new FileOutputStream(dest);zip(dir, outputStream);}
}

执行main函数跑测试用例，发现程序将dir路径下的所有文件已经压缩并输出zip包。