Java实现zip压缩多个文件下载

为了更好的演示，首先创建一个文件实体FileBean，包含了文件路径和文件名称：

package com.javaweb.entity;

import java.io.Serializable;
/**
 * 文件实体类*/
public class FileBean implements Serializable{
    
    private static final long serialVersionUID = -5452801884470115159L;
    
    private Integer fileId;//主键
    
    private String filePath;//文件保存路径
    
    private String fileName;//文件保存名称
    
    public FileBean(){
        
    }
       
    //Setters and Getters ...
}    

接下来，在控制层的方法里(示例为Spring MVC)，进行读入多个文件List<FileBean>，压缩成myfile.zip输出到浏览器的客户端：

    /**
     * 打包压缩下载文件
     */
    @RequestMapping(value = "/downLoadZipFile")
    public void downLoadZipFile(HttpServletResponse response) throws IOException{
        String zipName = "myfile.zip";
        List<FileBean> fileList = fileService.getFileList();//查询数据库中记录
        response.setContentType("APPLICATION/OCTET-STREAM");  
        response.setHeader("Content-Disposition","attachment; filename="+zipName);
        ZipOutputStream out = new ZipOutputStream(response.getOutputStream());
        try {
            for(Iterator<FileBean> it = fileList.iterator();it.hasNext();){
                FileBean file = it.next();
                ZipUtils.doCompress(file.getFilePath()+file.getFileName(), out);
                response.flushBuffer();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            out.close();
        }
    }

最后，附上ZipUtils压缩文件的工具类，这样便实现了多文件的压缩下载功能:

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

public class ZipUtils {
    
    private ZipUtils(){
    }
    
    public static void doCompress(String srcFile, String zipFile) throws IOException {
        doCompress(new File(srcFile), new File(zipFile));
    }
    
    /**
     * 文件压缩
     * @param srcFile 目录或者单个文件
     * @param zipFile 压缩后的ZIP文件
     */
    public static void doCompress(File srcFile, File zipFile) throws IOException {
        ZipOutputStream out = null;
        try {
            out = new ZipOutputStream(new FileOutputStream(zipFile));
            doCompress(srcFile, out);
        } catch (Exception e) {
            throw e;
        } finally {
            out.close();//记得关闭资源
        }
    }
    
    public static void doCompress(String filelName, ZipOutputStream out) throws IOException{
        doCompress(new File(filelName), out);
    }
    
    public static void doCompress(File file, ZipOutputStream out) throws IOException{
        doCompress(file, out, "");
    }
    
    public static void doCompress(File inFile, ZipOutputStream out, String dir) throws IOException {
        if ( inFile.isDirectory() ) {
            File[] files = inFile.listFiles();
            if (files!=null && files.length>0) {
                for (File file : files) {
                    String name = inFile.getName();
                    if (!"".equals(dir)) {
                        name = dir + "/" + name;
                    }
                    ZipUtils.doCompress(file, out, name);
                }
            }
        } else {
             ZipUtils.doZip(inFile, out, dir);
        }
    }
    
    public static void doZip(File inFile, ZipOutputStream out, String dir) throws IOException {
        String entryName = null;
        if (!"".equals(dir)) {
            entryName = dir + "/" + inFile.getName();
        } else {
            entryName = inFile.getName();
        }
        ZipEntry entry = new ZipEntry(entryName);
        out.putNextEntry(entry);
        
        int len = 0 ;
        byte[] buffer = new byte[1024];
        FileInputStream fis = new FileInputStream(inFile);
        while ((len = fis.read(buffer)) > 0) {
            out.write(buffer, 0, len);
            out.flush();
        }
        out.closeEntry();
        fis.close();
    }
    
    public static void main(String[] args) throws IOException {
        doCompress("D:/java/", "D:/java.zip");
    }
    
}

其他：spring mvc 下载普通单个文件的方法：

    @RequestMapping(value = "/downloadFile")
    @ResponseBody
    public void downloadFile (HttpServletResponse response) {
          OutputStream os  = null;
          try {
　　　　　　　os = response.getOutputStream();
　　　　　　　File file = new File("D:/javaweb/demo.txt");
　　　　　　　// Spring工具获取项目resources里的文件
　　　　　　　File file2 = ResourceUtils.getFile("classpath:shell/init.sh");
            if(!file.exists()){
　　　　　　　　　　return;
　　　　　　　}
            response.reset();
            response.setHeader("Content-Disposition", "attachment;filename=demo.txt");
            response.setContentType("application/octet-stream; charset=utf-8");
            os.write(FileUtils.readFileToByteArray(file));
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            IOUtils.closeQuietly(os);
        }
        
    }

补充，另外一种 利用 ResponseEntity<byte[]> 实现下载单个文件的方法：

    /**
     * Spring下载文件
     * @param request
     * @throws IOException 
     */
    @RequestMapping(value="/download")
    public ResponseEntity<byte[]> download(HttpServletRequest request) throws IOException{
　　　　 // 获取项目webapp目录路径下的文件
        String path = request.getSession().getServletContext().getRealPath("/");
        File file = new File(path+"/soft/javaweb.txt");
        HttpHeaders headers = new HttpHeaders();  
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
        headers.setContentDispositionFormData("attachment", "javaweb.txt");
        return new ResponseEntity<byte[]>(org.apache.commons.io.FileUtils.readFileToByteArray(file),headers, HttpStatus.CREATED);
    }
　　
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