多文件打包下载以及单文件下载

今天项目中需要多文件打包下载和单文件下载的功能，以下做一些总结。

原代码：

package com.hlbj.utils;

import java.io.File; 
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.lang3.StringUtils;

import com.app.core.common.Config;
import com.hlbj.pdf.component.GeneratePdf;

public class DownLoadUitls {
        //图片地址
    private static String physicalPath = "";
        //多文件压缩下载
    public static boolean downLoadPic(String filePathstr, String fileNamestr, HttpServletResponse response) {
        boolean isgood = false;

        if (StringUtils.isBlank(filePathstr) || StringUtils.isBlank(fileNamestr)) {
            return isgood;
        }

        String[] filePaths = filePathstr.split(",");
        String[] fileNames = fileNamestr.split(",");

        if (filePaths == null || filePaths.length == 0 || fileNames == null || fileNames.length == 0) {
            return isgood;
        }

        String classpath = "";
        if (StringUtils.isNoneBlank(physicalPath)) {
            classpath = physicalPath;
        } else {
            classpath = GeneratePdf.class.getClassLoader().getResource("").getPath();
            classpath = classpath.substring(0, classpath.lastIndexOf("hlbj_api") - 1);
        }

        List<FileInputStream> inputs = new ArrayList<FileInputStream>();
        try {
            for (String path : filePaths) {
                String str = classpath + path.substring(path.indexOf("/s4m3files"));
                File file = new File(str);
                if (file.exists()) {
                    FileInputStream input = new FileInputStream(file);
                    inputs.add(input);
                }
            }

            // ZIP打包图片
            String downPath = classpath + "/images.zip";
            File zipFile = new File(downPath);
            byte[] buf = new byte[1024];
            int len;
            ZipOutputStream zout = new ZipOutputStream(new FileOutputStream(zipFile));
            for (int i = 0; i < inputs.size(); i++) {
                FileInputStream in = inputs.get(i);
                zout.putNextEntry(new ZipEntry(fileNames[i]));
                while ((len = in.read(buf)) > 0) {
                    zout.write(buf, 0, len);
                }
                zout.closeEntry();
                in.close();
            }
            zout.close();

            // 下载图片
            FileInputStream zipInput = new FileInputStream(zipFile);
            OutputStream out = response.getOutputStream();
            response.setContentType("application/octet-stream");
            response.setHeader("Content-Disposition", "attachment; filename=images.zip");
            while ((len = zipInput.read(buf)) != -1) {
                out.write(buf, 0, len);
            }
            zipInput.close();
            out.flush();
            out.close();
            // 删除压缩包
            zipFile.delete();
            isgood = true;
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return isgood;
    }
    //单文件下载
    public static void downLoadPdf(String filePathstr, HttpServletResponse response) {
        String classpath = "";
        if (StringUtils.isNoneBlank(physicalPath)) {
            classpath = physicalPath;
        } else {
            classpath = GeneratePdf.class.getClassLoader().getResource("").getPath();
            classpath = classpath.substring(0, classpath.lastIndexOf("hlbj_api") - 1);
        }
        filePathstr= classpath + filePathstr.substring(filePathstr.indexOf("/pdf"));
        // 下载本地文件
        // path是指欲下载的文件的路径。
        File file = new File(filePathstr);
        // 取得文件名。
        String filename = file.getName();
        // 读到流中
        InputStream inStream;


        try {
            inStream = new FileInputStream(filePathstr);
            // 设置输出的格式
            response.reset();
            response.setContentType("bin");
            response.addHeader("Content-Disposition", "attachment; filename="" + filename + """);
            // 循环取出流中的数据
            byte[] b = new byte[100];
            int len;
            while ((len = inStream.read(b)) > 0){
                response.getOutputStream().write(b, 0, len);
            }
            inStream.close();
        } catch (Exception e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        } // 文件的存放路径
    }
}