代码示例

具体代码如下:

import org.apache.commons.io.FileUtils;

import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.nio.file.Files;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

public class FileUtil {

    /**
     * 创建临时文件
     * @param inputStream 输入流
     * @param name 文件名称
     * @param ext 文件后缀
     * @param tmpDirFile 文件
     * @return
     * @throws IOException
     */
    public static File createTmpFile(InputStream inputStream, String name, String ext, File tmpDirFile) throws IOException {
        File resultFile = new File(tmpDirFile.getPath()+File.separator+name+"."+ext);
        resultFile.deleteOnExit();
        FileUtils.copyToFile(inputStream, resultFile);
        return resultFile;
    }

    /**
     * Byte转成File
     * @param bytes 文件数据
     * @param fileType 文件类型
     * @param fileName 文件名称
     * @return
     * @throws IOException
     */
    public static File bytesToFile(byte[] bytes, String fileType,String fileName) throws IOException {
        return createTmpFile(new ByteArrayInputStream(bytes),
                fileName,
                fileType,
                Files.createTempDirectory("tempFile").toFile());
    }

    public final static String ROOT_PATH = System.getProperty("user.dir") + File.separator;
    /**
     * 文件打包下载
     * @param files
     * @param fileName 文件压缩包的名字
     * @param response
     * @return
     * @throws Exception
     */
    public static HttpServletResponse downLoadFiles(List<File> files, String fileName, HttpServletResponse response) throws Exception {
        try {
            //创建一个临时压缩文件，把文件流全部注入到这个文件中
            SimpleDateFormat dateformate = new SimpleDateFormat("yyyyMMddhhmmss");
            String name = dateformate.format(new Date()) + ".zip";
            File file = new File(ROOT_PATH + fileName.concat(name));
            if (!file.exists()) {
                file.createNewFile();
            }
            response.reset();

            //创建文件输出流
            FileOutputStream fous = new FileOutputStream(file);

            //打包的方法我们会用到ZipOutputStream这样一个输出流,所以这里我们把输出流转换一下
            //org.apache.tools.zip.ZipOutputStream
            ZipOutputStream zipOut = new ZipOutputStream(fous);
            //这个方法接受的就是一个所要打包文件的集合，
            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
     */
    public static void zipFile(List files, ZipOutputStream outputStream) {
        int size = files.size();
        for (int i = 0; i < size; i++) {
            File file = (File) files.get(i);
            zipFile(file, outputStream);
        }
    }

    /**
     * 浏览器下载压缩文件
     * @param file Zip压缩文件
     * @param response
     * @return
     */
    public static HttpServletResponse downloadZip(File file, HttpServletResponse response) {
        try {
            // 以流的形式下载文件。
            InputStream fis = new BufferedInputStream(new FileInputStream(file.getPath()));
            byte[] buffer = new byte[fis.available()];
            fis.read(buffer);
            fis.close();
            // 清空response
            response.reset();

            OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/octet-stream");
            response.setHeader("Content-Disposition", "attachment; filename=" + new String(file.getName().getBytes("UTF-8"), "ISO-8859-1"));

            toClient.write(buffer);
            toClient.flush();
            toClient.close();
        } catch (IOException ex) {
            ex.printStackTrace();
        } finally {
            try {
                File f = new File(file.getPath());
                f.delete();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return response;
    }

    /**
     * 根据输入的文件与输出流对文件进行打包
     *
     * @param outputStream Zip输出流
     * @param inputFile 文件输入流
     */
    public static void zipFile(File inputFile, ZipOutputStream outputStream) {
        try {
            if (inputFile.exists()) {
                // 如果是目录的话这里是不采取操作的，
                if (inputFile.isFile()) {
                    FileInputStream IN = new FileInputStream(inputFile);
                    BufferedInputStream bins = new BufferedInputStream(IN, 512);
                    //org.apache.tools.zip.ZipEntry
                    ZipEntry entry = new ZipEntry(inputFile.getName());
                    outputStream.putNextEntry(entry);
                    // 向压缩文件中输出数据
                    int nNumber;
                    byte[] buffer = new byte[1024];
                    while ((nNumber = bins.read(buffer)) != -1) {
                        outputStream.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], outputStream);
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}