上傳附件代碼：借助commons-fileupload-1.2.jar

package com.str;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.util.Iterator;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

public class UploadServlet extends HttpServlet {

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
doGet(req, resp);
}


@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {

HttpServletRequest request = (HttpServletRequest)req;
HttpServletResponse response = (HttpServletResponse)resp;

/* response.setContentType("text/html;charset=gb2312");
response.setCharacterEncoding("utf-8");*/

OutputStream outputStream = null;
InputStream inputStream = null;

DiskFileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload fileUpload = new ServletFileUpload(factory);

try {
List items = fileUpload.parseRequest(request);
for (Iterator iterator = items.iterator(); iterator.hasNext();) {
FileItem name = (FileItem) iterator.next();
if(!name.isFormField()){
String fieldName = name.getFieldName(); //這個是name值
String fileName = name.getName(); //這個是全路徑
String lastFileName ="";

//這句話獲取的是源文件的原名稱，不做任何修改
String oldNamePath = fileName.substring(fileName.lastIndexOf("\\")+1);

if(fileName.endsWith(".docx")|| fileName.endsWith(".xls")){

lastFileName = request.getRealPath("/")+"\\upload\\"+ oldNamePath;
outputStream = new FileOutputStream(new File(lastFileName ));

inputStream = name.getInputStream();
byte[] bs = new byte[1024];
int length = 0;
while(null != inputStream && (length = inputStream.read(bs))!=-1){
outputStream.write(bs);
}
}
outputStream.flush();
}
//把lastFileName存到數據庫（這裏就不寫了不只lz用的什麽方式）}
}
} catch (Exception e) {
e.printStackTrace();
}

}
}

單個下載文件，批量下載文件代碼：借助於ant.jar包的ZipOutputStream、ZipEntry

package com.str;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.tools.zip.ZipEntry;
import org.apache.tools.zip.ZipOutputStream;

public class LoadServlet extends HttpServlet {

@Override
/*protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {

String path = getServletContext().getRealPath("/") + "\\upload";
OutputStream o = resp.getOutputStream();
byte b[] = new byte[1024];

//這個地方的文件，可以從數據庫中動態查找，我這邊寫死了為了簡單展示
File fileLoad = new File(path, "解析類型配置.xls");

String filename = new String("解析類型配置.xls".getBytes("gbk"), "iso8859-1");

System.out.println(filename);

我記得在Excel導出數據的時候說過filename千萬別寫中文，其實經過以下：
String filename = new String("解析類型配置.xls".getBytes("gbk"), "iso8859-1");
轉換以後，文件無論是中文、英文，都不會出現亂碼情況，本人已驗證

resp.setHeader("Content-disposition", "attachment;filename="+ filename);

long fileLength = fileLoad.length();
String length = String.valueOf(fileLength);
resp.setHeader("Content_Length", length);
FileInputStream in = new FileInputStream(fileLoad);
int n = 0;
while ((n = in.read(b)) != -1) {
o.write(b, 0, n);
}
}*/

//以上是單個下載附件，這邊是批量壓縮下載附件
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {

String zipFileName = "test.zip";

//這些文件都是存在的，我是寫死了的，可以從頁面傳名稱過來
String[] filePathArray = {"1.jpg","2.jpg","3.xls","測試.docx"};
String path = getServletContext().getRealPath("/") + "\\image";

resp.setContentType("application/x-msdownload" ); // 通知客戶文件的MIME類型：
resp.setHeader("Content-disposition","attachment;filename=" + zipFileName);

ZipOutputStream zos = new ZipOutputStream(resp.getOutputStream());

for (String filePath : filePathArray) {
File file = new File(path + File.separator + filePath);
doZip(file, zos);
}
zos.close();
}

//處理批量下載時候，文件壓縮問題
private void doZip(File file, ZipOutputStream zos) throws IOException {
if(file.exists()) {
if (file.isFile()) {
//如果是文件，寫入到 zip 流中
String fileName = file.getName();

ZipEntry zet = new ZipEntry(file.getName());
zos.putNextEntry(zet);
FileInputStream fis = new FileInputStream(file);
byte[] buffer = new byte[1024];
int r = 0;
while ((r = fis.read(buffer)) != -1) {
zos.write(buffer, 0, r);
}
zos.setEncoding("gbk"); //這個地方很重要
zos.flush();
fis.close();
}else {
System.out.println("不是文件，那就不下載了，因為前臺會做處理，此處就不在一步步進行驗證了!");
}
}
}

}

java上傳附件，批量下載附件(一)