package com.business.testExcelPort;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
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.net.URLEncoder;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
import java.util.Random;

import javax.servlet.http.HttpServletResponse;
import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.read.listener.ReadListener;
import com.alibaba.excel.support.ExcelTypeEnum;

import org.apache.log4j.Logger;
import org.apache.tools.zip.ZipEntry;
import org.apache.tools.zip.ZipOutputStream;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

/**
 * @ClassName DownLoad
 * @Deacription TODO
 * @Author SEN
 * @Date 2020/2/10 0010 17:49
 * @Version 1.0
 **/

@Controller
@RequestMapping("/download")
@Slf4j
public class DownLoad {
    private Logger Log = Logger.getLogger(DownLoad.class);
    // 获取当前系统的临时目录
    private static final String FilePath = System.getProperty("java.io.tmpdir") + File.separator;
    
    @RequestMapping(value = "/execute", method=RequestMethod.GET)
    public void execute(HttpServletResponse response) {
        // 用于存放文件路径
        List<String> filePaths = new ArrayList<>();
        //生成的ZIP文件名为Demo.zip
        String tmpFileName = "Demo.zip";
        // zip文件路径
        String strZipPath = FilePath + tmpFileName;
        filePaths.add(strZipPath);
        try {
            //创建zip输出流
            ZipOutputStream out = new ZipOutputStream(new FileOutputStream(strZipPath));
            //声明文件集合用于存放excel文件
            List<File> fileList = new ArrayList<File>();
            //生成excel文件集合
            for (int i = 0; i < 10; i++) {
                // 生成随机文件名
                String filename = FilePath + generateRandomFilename() + ".xlsx";
                // 将文件路径保存
                fileList.add(creatFile(filename));
                filePaths.add(filename);
                List<DataOne> list = new ArrayList<>();
                for (int j = 0; j < 10; j++) {
                    // 造一些表格数据，一般是从数据库查出来的list集合数据
                    DataOne dataOne = new DataOne();
                    //。。。
                    list.add(dataOne);
                }
                // 使用easyexcel生成excel文件
                writeExcel(newFile, DataOne.class, list,ExcelTypeEnum.XLS);                
            }
            byte[] buffer = new byte[1024];
            //将excel文件放入zip压缩包
            for (int i = 0; i < fileList.size(); i++) {
                File file = fileList.get(i);
                FileInputStream fis = new FileInputStream(file);
                out.putNextEntry(new ZipEntry(file.getName()));
                //设置压缩文件内的字符编码，不然会变成乱码
                out.setEncoding("GBK");
                int len;
                // 读入需要下载的文件的内容，打包到zip文件
                while ((len = fis.read(buffer)) > 0) {
                    out.write(buffer, 0, len);
                }
                out.closeEntry();
                fis.close();
            }
            out.close();
            //下载zip文件
            this.downFile(response, tmpFileName,filePaths);
        } catch (Exception e) {
            // 下载失败删除生成的文件
            deleteFile(filePaths);
            Log.error("文件下载出错", e);
        }
    }


    /**
     * 文件下载
     *  @param response
     * @param str
     * @param filePaths
     */
    private void downFile(HttpServletResponse response, String str, List<String> filePaths) {
        try {
            String path = FilePath + str;
            File file = new File(path);
            if (file.exists()) {
                InputStream ins = new FileInputStream(path);
                BufferedInputStream bins = new BufferedInputStream(ins);// 放到缓冲流里面
                OutputStream outs = response.getOutputStream();// 获取文件输出IO流
                BufferedOutputStream bouts = new BufferedOutputStream(outs);
                response.setContentType("application/x-download");// 设置response内容的类型
                response.setHeader(
                        "Content-disposition",
                        "attachment;filename="
                                + URLEncoder.encode(str, "UTF-8"));// 设置头部信息
                int bytesRead = 0;
                byte[] buffer = new byte[8192];
                // 开始向网络传输文件流
                while ((bytesRead = bins.read(buffer, 0, 8192)) != -1) {
                    bouts.write(buffer, 0, bytesRead);
                }
                bouts.flush();// 这里一定要调用flush()方法
                ins.close();
                bins.close();
                outs.close();
                bouts.close();
                deleteFile(filePaths);
            }
        } catch (IOException e) {
            deleteFile(filePaths);
            Log.error("文件下载出错", e);
        }
    }
    //创建文件File对象
    private File creatFile(String filePath) {
        File file = new File(filePath);
        return file;
    }
    //生成随机文件名
    public String generateRandomFilename() {
        String RandomFilename = "";
        Random rand = new Random();//生成随机数
        int random = rand.nextInt();
        Calendar calCurrent = Calendar.getInstance();
        int intDay = calCurrent.get(Calendar.DATE);
        int intMonth = calCurrent.get(Calendar.MONTH) + 1;
        int intYear = calCurrent.get(Calendar.YEAR);
        String now = String.valueOf(intYear) + "_" + String.valueOf(intMonth) + "_" +
                String.valueOf(intDay) + "_";

        RandomFilename = now + String.valueOf(random > 0 ? random : (-1) * random);
        return RandomFilename;
    }
    //删除文件
    public static boolean deleteFile(List<String> filePath){
        boolean result = false;
        for (String pathname:filePath){
            File file = new File(pathname);
            if (file.exists()) {
                file.delete();
                result = true;
            }
        }
        return result;
    }
    /**
     * @Title: writeExcel
     * @Description: 写入excel文件到输出流web端
     *
     */
    private void writeExcel(OutputStream outputStream, Class<?> clazz, List<?> datalist,ExcelTypeEnum excelType,String sheetName) throws IOException {
        EasyExcel.write(outputStream, clazz).excelType(excelType).sheet(sheetName==null ? "sheet1":sheetName).doWrite(datalist);
        outputStream.flush();
    }

    /**
     * @Title: writeExcel
     * @Description: 写入excel到本地路径
     */
    private void writeExcel(File newFile, Class<?> clazz, List<?> datalist,ExcelTypeEnum excelType) {
        EasyExcel.write(newFile, clazz).excelType(excelType).sheet("sheet1").doWrite(datalist);
    }

    /**
     * @Title: readExcel
     * @Description: 读取excel内容（从输入流）
     */
    private List<?> readExcel(InputStream inputStream, Class<?> clazz, ReadListener<?> listener) {
        List<?> list = null;
        list = EasyExcel.read(inputStream, clazz, listener).sheet().doReadSync();
        return list;
    };
}