打包下载文件：

public String downZipDoc() throws IOException {
        HttpServletResponse response = ServletActionContext.getResponse();
        //查询所有文档数据信息
        docattachmentList = docAttachmentService.selectList(map);
        if (docattachmentList.size() > 0) {
            String newFilePath = null;
            List<File> fileList = new ArrayList<>();
            //filePath 路径
            for (Docattachment e : docattachmentList) {
                File file = new File(filePath + e.getFilePath());
                if (!file.exists()) {
                    file.createNewFile();
                }
                //把保存的文件名称改为原来的名称
                newFilePath = filePath + e.getFilePath().substring(0, e.getFilePath().lastIndexOf("/")) + "/" + e.getFileName()
                        + e.getFilePath().substring(e.getFilePath().lastIndexOf("."));
                File newFile = new File(newFilePath);
                file.renameTo(newFile);
                fileList.add(newFile);
            }
            String zipFileName = "压缩包名称";
            DownloadFiles.downLoadFile1(fileList, response, zipFileName);

        }
        return null;
    }

工具类：

package com.gdzy.ZKZHFWPT.util;

import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.Date;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

import static com.gdzy.ZKZHFWPT.util.PropertiesUtil.getPropertiesValue;

public class DownloadFiles {

    public static HttpServletResponse downLoadFile(List<File> files, HttpServletResponse response){
        FileOutputStream fous = null;
        ZipOutputStream zipOut = null;
        String zipFilename =  getPropertiesValue("tempZipPath") + "/" + System.currentTimeMillis() + ".zip";
        try {
            File file = new File(zipFilename);
            if (!file.exists()){
                file.createNewFile();
            }
            response.reset();
            //创建文件输出流
            fous = new FileOutputStream(file);
            zipOut = new ZipOutputStream(fous);
            zipFile(files, zipOut);
            zipOut.close();
            fous.close();
            return downloadZip(file,response);
        }catch (Exception e) {
            e.printStackTrace();
        }
        return response ;
    }

    /**
     * 把接受的全部文件打成压缩包
     * @param List<File>;
     * @param org.apache.tools.zip.ZipOutputStream
     */
    public static void zipFile (List<File> files,ZipOutputStream outputStream) {
        int size = files.size();
        for(int i = 0; i < size; i++) {
            File file = (File) files.get(i);
            zipFile(file, outputStream);
        }
    }
    /**
     * 根据输入的文件与输出流对文件进行打包
     * @param File
     * @param org.apache.tools.zip.ZipOutputStream
     */
    public static void zipFile(File inputFile,  ZipOutputStream ouputStream) {
        FileInputStream IN = null;
        BufferedInputStream bins = null;
        try {
            if(inputFile.exists()) {
                if (inputFile.isFile()) {
                    IN = new FileInputStream(inputFile);
                    bins = new BufferedInputStream(IN, 512);
                    ZipEntry entry = new ZipEntry(inputFile.getName());
                    ouputStream.putNextEntry(entry);
                    // 向压缩文件中输出数据
                    int nNumber;
                    byte[] buffer = new byte[512];
                    while ((nNumber = bins.read(buffer)) != -1) {
                        ouputStream.write(buffer, 0, nNumber);
                    }
                    // 关闭创建的流对象
                    bins.close();
                    IN.close();
                } else {
                    try {
                        File[] files = inputFile.listFiles();
                        for (int i = 0; i < files.length; i++) {
                            zipFile(files[i], ouputStream);
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    public static HttpServletResponse downLoadFile1(List<File> files, HttpServletResponse response,String zipFileName){
        FileOutputStream fous = null;
        ZipOutputStream zipOut = null;
        String zipFilename =  getPropertiesValue("tempZipPath") + "/" + zipFileName + ".zip";
        try {
            File file = new File(zipFilename);
            File filePath = new File(getPropertiesValue("tempZipPath"));
            if (!filePath.exists()){
                filePath.mkdir();
            }
            if (!file.exists()){
                file.createNewFile();
            }
            response.reset();
            //创建文件输出流
            fous = new FileOutputStream(file);
            zipOut = new ZipOutputStream(fous);
            zipFile(files, zipOut);
            zipOut.close();
            fous.close();
            return downloadZip(file,response);
        }catch (Exception e) {
            e.printStackTrace();
        }
        return response ;
    }

}