简单介绍下我实现的功能,首先是我的excel上传,它是以blob字段存储在oracel数据库中的,我实现的是循环遍历blob字段并使用io流进行打包下载,如有需要可自行修改
使用技术有,springMVC,mabits , bootstrap
1.前台
这里给出主要代码块
<div class="row">
<div class="col-md-12 ">
<a href="tab-trainer-info.htm?status=1" class="btn btn-danger" title='#springMessage("back")'> <i class="glyphicon glyphicon-step-backward"></i></a>
<a href="downloadPreHomeWorkZIP.htm?sessionId=$!sessionId" class="btn btn-info downloadPreZip" title='#springMessage("preWorkZip")'> <i class="glyphicon glyphicon-download-alt"></i> #springMessage("preWorkZip")</a>
<a href="downloadAfterHomeWorkZIP.htm?sessionId=$!sessionId" class="btn btn-info downloadAfterZip" title='#springMessage("afterWorkZip")'> <i class="glyphicon glyphicon-download-alt"></i> #springMessage("afterWorkZip")</a>
</div>
</div>
注意这里点击按钮时用的超链接,不要用的ajax提交,ajax慎用,我自己一开始使用的ajax,最后无法下载,搞了半天,后来百度,说ajax下载无法调用浏览器的下载机制,如果有必要也可以使用(要用form封装,我这里不再具体介绍,有尝试的小伙伴,可以共享一下,哈哈)
2. Controller 读取数据
@RequestMapping(value = "downloadPreHomeWorkZIP")
public void downloadLetterZIP(trainTraineeWorkModel query, HttpServletResponse response, HttpServletRequest request)
throws IOException, SQLException {
String serverPath = request.getSession().getServletContext().getRealPath("/") + "\\upload\\tempExcel"; //设置下载excel的临时文件夹
List<File> srcfile = new ArrayList<File>(); //声明一个集合,用来存放多个Excel文件路径及名称
// 得到路径下的文件,如果不存在创建文件夹
File file = new File(serverPath);
if (!file.exists()) {
file.mkdir();
}
List<Map> employees = employeeService // 查询学员上传的课前课后作业 (这里根据自己的需要获取数据,写入流中)
.getMapTraineesBySessionId(query.getSessionId());
if (employees.size() != 0) {
for (Map map : employees) {
BLOB blob = (BLOB) map.get("BEFORECLASS_WORK");
if (blob != null && blob.length() != 0) {
String employeeCode = (String) map.get("EMPLOYEE_CODE");
String filename = employeeCode + "_" + DateUtil.getExportDate(); //定义现在excel文件名称,注意这里不是压缩包的名称
ZipUtils.execute(serverPath +"\\"+ filename+ ".xls", blob); //ZipUtils是我自己定义的一个工具类,因为用到的下载太多了,往下看
String encodedfileName = new String(filename.getBytes(), "UTF-8");
srcfile.add(new File(serverPath + "\\" + encodedfileName + ".xls")); //存放到List集合中
}
}
// 将服务器上存放Excel的文件夹打成zip包
File zipfile = new File(serverPath+"\\" + "PreWork" + ".zip");
ZipUtils.zipFiles(srcfile, zipfile);// 实现将多个excel打包成zip文件
//下载
ZipUtils.downFile(response, serverPath, "PreWork" + ".zip"); //实现将压缩包写入流中,下载到本地,并删除临时文件中的压缩包及文件
}
}
3.使用工具类
这里是我第二步说的自己定义的工具类,我用的maven,需要导入一些Io流包
package common.util;
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.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
import javax.servlet.http.HttpServletResponse;
import oracle.sql.BLOB;
public class ZipUtils {
/**
* 将多个Excel打包成zip文件
* @param srcfile
* @param zipfile
*/
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) {
e.printStackTrace();
}
}
//filename为单个excel的路径和excel的名称,blob就是获取的blob数据
public static int execute(String filename, BLOB blob)
{
int success = 1;
try
{
File blobFile = new File(filename);
FileOutputStream outStream = new FileOutputStream(blobFile);
InputStream inStream = blob.getBinaryStream();
int length = -1;
int size = blob.getBufferSize();
byte[] buffer = new byte[size];
while ((length = inStream.read(buffer)) != -1)
{
outStream.write(buffer, 0, length);
outStream.flush();
}
inStream.close();
outStream.close();
}
catch (Exception e)
{
e.printStackTrace();
success = 0;
}
finally
{
return success;
}
}
/**
* 删除目录下所有的文件;
* @param path
*/
public static boolean deleteExcelPath(File file){
String[] files = null;
if(file != null){
files = file.list();
}
if(file.isDirectory()){
for(int i =0;i<files.length;i++){
boolean bol = deleteExcelPath(new File(file,files[i]));
if(bol){
System.out.println("删除成功!");
}else{
System.out.println("删除失败!");
}
}
}
return file.delete();
}
public static void downFile(HttpServletResponse response,String serverPath, String str) {
//下面注释代码虽然少,但是慎用,如果使用,压缩包能下载,但是下载之后临时文件夹会被锁住被jvm占用,不能删除
// response.setCharacterEncoding("utf-8");
// try {
// File file=new File(serverPath,str);
// response.setHeader("Content-Disposition",
// "attachment; filename="+ StringUtil.encodingFileName(str));
// response.setContentType("application/octet-stream; charset=utf-8");
// InputStream in1 =new FileInputStream(file.getPath());
// IOUtils.copy(in1, response.getOutputStream());
//
// }
// catch (IOException ex) {
// ex.printStackTrace();
// }
try {
String path = serverPath +"\\"+ 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/ostet-stream");// 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();
} else {
response.sendRedirect("../error.jsp");
}
} catch (IOException e) {
e.printStackTrace();
}finally{
File file1=new File(serverPath);
deleteExcelPath(file1); //删除临时目录
}
}
}