java实现csv导出千万级数据实例

package com.onmusic.controller.junit.excel; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.io.*; import java.util.ArrayList; import java.util.Enumeration; import java.util.List; import java.util.zip.ZipEntry; import java.util.zip.ZipFile; import java.util.zip.ZipOutputStream; public class ZipUtil { private static final Log log = LogFactory.getLog(ZipUtil.class); /** * 压缩文件 * * @param srcfile File[] 需要压缩的文件列表 * @param zipfile File 压缩后的文件 */ public static void zipFiles(List<File> srcfile, File zipfile) { byte[] buf = new byte[1024]; try { // Create the ZIP file ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipfile)); // Compress the files for (int i = 0; i < srcfile.size(); i++) { File file = srcfile.get(i); FileInputStream in = new FileInputStream(file); // Add ZIP entry to output stream. out.putNextEntry(new ZipEntry(file.getName())); // Transfer bytes from the file to the ZIP file int len; while ((len = in.read(buf)) > 0) { out.write(buf, 0, len); } // Complete the entry out.closeEntry(); in.close(); } // Complete the ZIP file out.close(); } catch (IOException e) { log.error("ZipUtil zipFiles exception:"+e); } } /** * 解压缩 * * @param zipfile File 需要解压缩的文件 * @param descDir String 解压后的目标目录 */ public static void unZipFiles(File zipfile, String descDir) { try { // Open the ZIP file ZipFile zf = new ZipFile(zipfile); for (Enumeration entries = zf.entries(); entries.hasMoreElements();) { // Get the entry name ZipEntry entry = ((ZipEntry) entries.nextElement()); String zipEntryName = entry.getName(); InputStream in = zf.getInputStream(entry); // System.out.println(zipEntryName); OutputStream out = new FileOutputStream(descDir + zipEntryName); byte[] buf1 = new byte[1024]; int len; while ((len = in.read(buf1)) > 0) { out.write(buf1, 0, len); } // Close the file and stream in.close(); out.close(); } } catch (IOException e) { log.error("ZipUtil unZipFiles exception:"+e); } } /** * 将指定文件夹打包成zip * @param folder * @throws IOException */ public static void zipFile(String folder) throws IOException { File zipFile = new File(folder + ".zip"); if (zipFile.exists()) { zipFile.delete(); } ZipOutputStream zipout = new ZipOutputStream(new FileOutputStream(zipFile)); File dir = new File(folder); File[] fs = dir.listFiles(); byte[] buf = null; if(fs!=null){ for (File f : fs) { zipout.putNextEntry(new ZipEntry(f.getName())); FileInputStream fileInputStream = new FileInputStream(f); buf = new byte[2048]; BufferedInputStream origin = new BufferedInputStream(fileInputStream,2048); int len; while ((len = origin.read(buf,0,2048))!=-1) { zipout.write(buf,0,len); } zipout.flush(); origin.close(); fileInputStream.close(); } } zipout.flush(); zipout.close(); } /** * 删除文件夹 * @param file */ public static void dropFolderOrFile(File file) { if (file.isDirectory()) { File[] fs = file.listFiles(); for (File f : fs) { dropFolderOrFile(f); } } file.delete(); } /**导出 * @param response * @param fileName * @return * @throws IOException */ // public static void downloadFile(HttpServletRequest request,HttpServletResponse response,StringBuilder uri) // throws IOException { // //获取服务其上的文件名称 // StringBuffer filename = new StringBuffer(); // filename.append(request.getSession().getServletContext().getRealPath("/")); // filename.append(uri); // File file = new File(filename.toString()); // // StringBuffer sb = new StringBuffer(); // sb.append("attachment; filename=").append(uri.substring(uri.lastIndexOf("//")+1)); // response.setHeader("Expires", "0"); // response.setHeader("Cache-Control","must-revalidate, post-check=0, pre-check=0"); // response.setHeader("Pragma", "public"); // response.setContentType("application/x-msdownload;charset=UTF-8"); // response.setHeader("Content-Disposition", new String( sb.toString().getBytes(), "ISO8859-1")); // // //将此文件流写入到response输出流中 // FileInputStream inputStream = new FileInputStream(file); // OutputStream outputStream = response.getOutputStream(); // byte[] buffer = new byte[1024]; // int i = -1; // while ((i = inputStream.read(buffer)) != -1) { // outputStream.write(buffer, 0, i); // } // outputStream.flush(); // outputStream.close(); // inputStream.close(); // } /** * Main * * @param args */ public static void main(String[] args) { List<File> srcfile=new ArrayList<File>(); srcfile.add(new File("C:\\cap4j\\download\\客户列表3.csv")); srcfile.add(new File("C:\\cap4j\\download\\客户列表4.csv")); File zipfile = new File("C:\\cap4j\\download\\edm.zip"); ZipUtil.zipFiles(srcfile, zipfile); } }