java/resteasy批量下载存储在阿里云OSS上的文件，并打包压缩

现在需要从oss上面批量下载文件并压缩打包，搜了很多相关博客，均是缺胳膊少腿，要么是和官网说法不一，要么就压缩包工具类不给出

官方API https://help.aliyun.com/document_detail/32014.html?spm=a2c4g.11186623.6.683.txHAjx

我们采用流式下载，进行简单改装，可以从OSS取到多个文件

思路：ossClient.getObject()获取到文件

再用输入流获取ossObject.getObjectContent()，再利用输入流写入到字节流中，

关闭输入输出流，结束

读取文件接口：

 /**
     * 根据订单编号查询多个大图路径
     * 从OSS取出来多个文件
     * 在"D:\\download"进行读取
     * 在"D:\\downloadZip"进行压缩
     * @param orderNumber
     * @return
     * @throws Exception
     */
    @GET
    @Path("readOssFile")
    @Produces(MediaType.APPLICATION_JSON)
    public PcsResult readOssFile(@QueryParam("orderNumber") String orderNumber) throws Exception {
        //orderNumber = 194785
        if(orderNumber==null){
            logger.error("订单编号不能为空!");
            throw new Exception("订单编号不能为空!");
        }
        List<Map<String,String>> imagePath = myOrderService.queryImageByOrderNumber(orderNumber);
        List<String> objectNames = new ArrayList<>();
        for (Map<String,String> image:imagePath){
            objectNames.add(image.get("imagePath"));
        }
        // 创建OSSClient实例。
        OSSClient ossClient = new OSSClient(END_POINT, ACCESSKEY_ID, ACCESSKEY_SECRET);
        //ossObject包含文件所在的存储空间名称、文件名称、文件元信息以及一个输入流。
        /*
            多文件，循环遍历ossClient的Object
         */
        for(int i=0;i<objectNames.size();i++) {
            OSSObject ossObject = ossClient.getObject(BUCKET_NAME, objectNames.get(i));
            File fileDir = new File(fileDirectory);
            FileToolUtil.judeDirExists(fileDir);
            // 读取文件内容。
            // file(内存)----输入流---->【程序】----输出流---->file(内存)
            File file = new File(fileDirectory, "addfile"+i+".png");
            BufferedInputStream in=null;
            BufferedOutputStream out=null;
            in=new BufferedInputStream(ossObject.getObjectContent());
            out=new BufferedOutputStream(new FileOutputStream(file));
            int len=-1;
            byte[] b=new byte[1024];
            while((len=in.read(b))!=-1){
                out.write(b,0,len);
            }
            //关闭输入输出流
            IOUtils.closeQuietly(out);
            IOUtils.closeQuietly(in);
        }

        //新建文件夹以备压缩文件存放
        File fileDir1 = new File(fileDirectory1);
        FileToolUtil.judeDirExists(fileDir1);
        //执行压缩操作
        ZipUtils.doCompress(fileDirectory, fileDirectory1+"\\" + orderNumber + ".zip");
        //数据读取完成后，获取的流必须关闭，否则会造成连接泄漏，导致请求无连接可用，程序无法正常工作。
        ossClient.shutdown();
        return newResult(true).setMessage("文件打包成功");
    }

写成流，设置response

下载文件接口：

/**
     * 流程
     * 再将"D:\\download"文件夹删除
     * 再将"D:\\download"文件夹删除
     * @return
     * @throws IOException
     */
    @GET
    @Path("getOssFile")
    @Produces(MediaType.APPLICATION_JSON)
    public void getOssFile(@QueryParam("orderNumber") String orderNumber,@Context HttpServletResponse response) throws Exception {

        //根据存放在fileDirectory1下的压缩文件生成下载请求
        OutputStream out = null;
        FileInputStream in = null;
        try {
            in = new FileInputStream(fileDirectory1+"\\"  + orderNumber + ".zip");
            String fileName = orderNumber + ".zip";
            //设置文件输出类型
            response.setContentType("application/octet-stream");
            response.setHeader("Content-disposition", "attachment; filename="
                    + new String(fileName.getBytes("utf-8"), "ISO8859-1"));

            byte[] data = FileToolUtil.inputStreamToByte(in);
            //设置输出长度
            response.setHeader("Content-Length", String.valueOf(data.length));
            out = response.getOutputStream();
            out.write(data);
            out.flush();

            //数据读取完成后，获取的流必须关闭，否则会造成连接泄漏，导致请求无连接可用，程序无法正常工作。
        }catch (Exception e){
            logger.error(".....getOssFile....", e);
        }finally {
            IOUtils.closeQuietly(out);
            IOUtils.closeQuietly(in);
            DeleteFileUtil.delete(fileDirectory);
            DeleteFileUtil.delete(fileDirectory1);
        }
    }

补充：ZipUtil.java

package com.xgt.util;

import java.io.*;
import java.util.zip.CRC32;
import java.util.zip.CheckedOutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

/**
 * ZIP压缩工具
 *
 * @since 1.0
 */
public class ZipUtils {

    public static final String EXT = ".zip";
    private static final String BASE_DIR = "";

    // 符号"/"用来作为目录标识判断符
    private static final String PATH = "/";
    private static final int BUFFER = 1024;

    /**
     * 压缩
     *
     * @param srcFile
     * @throws Exception
     */
    public static void compress(File srcFile) throws Exception {
        String name = srcFile.getName();
        String basePath = srcFile.getParent();
        String destPath = basePath + name + EXT;
        compress(srcFile, destPath);
    }

    /**
     * 压缩
     *
     * @param srcFile  源路径
     * @param destFile 目标路径
     * @throws Exception
     */
    public static void compress(File srcFile, File destFile) throws Exception {

        // 对输出文件做CRC32校验
        CheckedOutputStream cos = new CheckedOutputStream(new FileOutputStream(
                destFile), new CRC32());

        ZipOutputStream zos = new ZipOutputStream(cos);

        compress(srcFile, zos, BASE_DIR);

        zos.flush();
        zos.close();
    }

    /**
     * 压缩文件
     *
     * @param srcFile
     * @param destPath
     * @throws Exception
     */
    public static void compress(File srcFile, String destPath) throws Exception {
        compress(srcFile, new File(destPath));
    }

    /**
     * 压缩
     *
     * @param srcFile  源路径
     * @param zos      ZipOutputStream
     * @param basePath 压缩包内相对路径
     * @throws Exception
     */
    private static void compress(File srcFile, ZipOutputStream zos,
                                 String basePath) throws Exception {
        if (srcFile.isDirectory()) {
            compressDir(srcFile, zos, basePath);
        } else {
            compressFile(srcFile, zos, basePath);
        }
    }

    /**
     * 压缩
     *
     * @param srcPath
     * @throws Exception
     */
    public static void compress(String srcPath) throws Exception {
        File srcFile = new File(srcPath);

        compress(srcFile);
    }

    /**
     * 文件压缩
     *
     * @param srcPath  源文件路径
     * @param destPath 目标文件路径
     */
    public static void compress(String srcPath, String destPath)
            throws Exception {
        File srcFile = new File(srcPath);

        compress(srcFile, destPath);
    }

    /**
     * 压缩目录
     *
     * @param dir
     * @param zos
     * @param basePath
     * @throws Exception
     */
    private static void compressDir(File dir, ZipOutputStream zos,
                                    String basePath) throws Exception {

        File[] files = dir.listFiles();

        // 构建空目录
        if (files.length < 1) {
            ZipEntry entry = new ZipEntry(basePath + dir.getName() + PATH);

            zos.putNextEntry(entry);
            zos.closeEntry();
        }

        for (File file : files) {

            // 递归压缩
            compress(file, zos, basePath + dir.getName() + PATH);

        }
    }

    /**
     * 文件压缩
     *
     * @param file 待压缩文件
     * @param zos  ZipOutputStream
     * @param dir  压缩文件中的当前路径
     * @throws Exception
     */
    private static void compressFile(File file, ZipOutputStream zos, String dir)
            throws Exception {

        /**
         * 压缩包内文件名定义
         *
         * <pre>
         * 如果有多级目录，那么这里就需要给出包含目录的文件名
         * 如果用WinRAR打开压缩包，中文名将显示为乱码
         * </pre>
         */
        ZipEntry entry = new ZipEntry(dir + file.getName());

        zos.putNextEntry(entry);

        BufferedInputStream bis = new BufferedInputStream(new FileInputStream(
                file));

        int count;
        byte data[] = new byte[BUFFER];
        while ((count = bis.read(data, 0, BUFFER)) != -1) {
            zos.write(data, 0, count);
        }
        bis.close();

        zos.closeEntry();
    }

    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("E:\\py交易\\download", "E:\\py交易\\download\\效果图批量下载.zip");
    }

}

FileToolUtil.java

package com.xgt.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;

public class FileToolUtil {
    private static final Logger logger = LoggerFactory.getLogger(FileToolUtil.class);
    /**
     * @author cjy
     * @date 2018/6/5 14:35
     * @param file
     * @return
     */
    // 判断文件夹是否存在
    public static void judeDirExists(File file) {

        if (file.exists()) {
            if (file.isDirectory()) {
                System.out.println("dir exists");
            } else {
                System.out.println("the same name file exists, can not create dir");
            }
        } else {
            System.out.println("dir not exists, create it ...");
            file.mkdir();
        }

    }

}