ajax文件上传核心代码

来源：互联网发布：虚拟淘宝店怎么开编辑：程序博客网时间：2024/06/05 09:19

ajax文件上传核心代码

private void doFileUpload(HttpSession session, HttpServletRequest request,

HttpServletResponse response) throws IOException {

try {

// 创建UploadListener对象

UploadListener listener = new UploadListener(request

.getContentLength());

listener.start();// 启动监听状态

// 将监听器对象的状态保存在Session中

session.setAttribute("FILE_UPLOAD_STATS", listener

.getFileUploadStats());

session.setAttribute("bytesRead","0");

// 创建MonitoredDiskFileItemFactory对象

FileItemFactory factory = new MonitoredDiskFileItemFactory(listener);

// 通过该工厂对象创建ServletFileUpload对象

ServletFileUpload upload = new ServletFileUpload(factory);

// 将转化请求保存到list对象中

List items = upload.parseRequest(request);

// 停止使用监听器

listener.done();

boolean hasError = false;

// 循环list中的对象

for (Iterator i = items.iterator(); i.hasNext();) {

FileItem fileItem = (FileItem) i.next();

if (!fileItem.isFormField()) {// 如果该FileItem不是表单域

processUploadedFile(fileItem,session);// 调用processUploadedFile方法,将数据保存到文件中

fileItem.delete();// 内存中删除该数据流

}

if (!hasError) {// 如果没有出现错误

sendCompleteResponse(response, null);// 调用sendCompleteResponse方法

} else {

sendCompleteResponse(response,

"Could not process uploaded file. Please see log for details.");

}

} catch (Exception e) {

sendCompleteResponse(response, e.getMessage());

}

}public void processUploadedFile(FileItem item,HttpSession session) {

// 获得上传文件的文件名

String fileName = item.getName().substring(

item.getName().lastIndexOf("//") + 1);

// 创建File对象,将上传得文件保存到C://upload文件夹下

File file = new File("C://upload//", fileName);

InputStream in;

try {

in = item.getInputStream();// 获得输入数据流文件

// 将该数据流写入到指定文件中

FileOutputStream out = new FileOutputStream(file);

byte[] buffer = new byte[4096]; // To hold file contents

int bytes_read;

long bytesRead = Long.parseLong((String) session.getAttribute("bytesRead"));// 已读数据大小

while ((bytes_read = in.read(buffer)) != -1) // Read until EOF

{

out.write(buffer, 0, bytes_read);

bytesRead+=(long)bytes_read;

session.setAttribute("bytesRead",String.valueOf(bytesRead));

}

UploadListener.FileUploadStats fileUploadStats = (UploadListener.FileUploadStats) session

.getAttribute("FILE_UPLOAD_STATS");

long sizeTotal = fileUploadStats.getTotalSize();// 获得上传文件的总大小

session.setAttribute("bytesRead",String.valueOf(sizeTotal));

if (in != null)

try {

in.close();

} catch (IOException e) {

;

}

if (out != null)

try {

out.close();

} catch (IOException e) {

;

}

} catch (IOException e1) {

e1.printStackTrace();

}

private void doStatus(HttpSession session, HttpServletResponse response)

throws IOException {

// 设置该响应不在缓存中读取

response.addHeader("Expires", "0");

response.addHeader("Cache-Control",

"no-store, no-cache, must-revalidate");

response.addHeader("Cache-Control", "post-check=0, pre-check=0");

response.addHeader("Pragma", "no-cache");

// 获得保存在Session中的状态信息

UploadListener.FileUploadStats fileUploadStats = (UploadListener.FileUploadStats) session

.getAttribute("FILE_UPLOAD_STATS");

if (fileUploadStats != null) {

//long +fileUploadStats.getBytesRead();

//System.out.println(bytesProcessed);

long bytesProcessed = fileUploadStats.getBytesRead();// 获得已经上传的数据大小

long sizeTotal = fileUploadStats.getTotalSize();// 获得上传文件的总大小

// 计算上传完成的百分比

long percentComplete = (long) Math

.floor(((double) bytesProcessed / (double) sizeTotal) * 100.0);

// 获得上传已用的时间

long timeInSeconds = fileUploadStats.getElapsedTimeInSeconds();

// 计算平均上传速率

double uploadRate = bytesProcessed / (timeInSeconds + 0.00001);

// 计算总共所需时间

double estimatedRuntime = sizeTotal / (uploadRate + 0.00001);

// 将上传状态返回给客户端

response.getWriter().println("<b>上传状态:</b><br/>");

if (bytesProcessed != sizeTotal) {

response.getWriter().println(

"<div class=/"prog-border/"><div class=/"prog-bar/" style=/"width: "

+ percentComplete + "%;/"></div></div>");

response.getWriter().println(

"完成: " + bytesProcessed + " 总大小： " + sizeTotal

+ " bytes (" + percentComplete + "%) "

+ (long) Math.round(uploadRate / 1024)

+ " Kbs <br/>");

response.getWriter().println(

"用时: " + formatTime(timeInSeconds) + " 总时间： "

+ formatTime(estimatedRuntime) + " 剩余时间："

+ formatTime(estimatedRuntime - timeInSeconds)

+ "<br/>");

} else {

response.getWriter().println(

"完成: " + bytesProcessed + " 总大小： " + sizeTotal

+ " bytes<br/>");

response.getWriter().println("上传完成.<br/>");

}

//如果文件已经上传完毕

if (fileUploadStats.getBytesRead() == fileUploadStats

.getTotalSize()) {

response.getWriter().println("<b>上传完成,正在保存文件... ...</b><br/>");

//写文件

bytesProcessed =Long.parseLong((String) session.getAttribute("bytesRead"));

percentComplete = (long) Math

.floor(((double) bytesProcessed / (double) sizeTotal) * 100.0);

if (bytesProcessed != sizeTotal) {

response.getWriter().println(

"<div class=/"prog-border/"><div class=/"prog-bar/" style=/"width: "

+ percentComplete + "%;/"></div></div>");

response.getWriter().println(

"保存: " + bytesProcessed + " 总大小： " + sizeTotal

+ " bytes (" + percentComplete + "%) <br/>");

} else {

response.getWriter().println(

"保存: " + bytesProcessed + " 总大小： " + sizeTotal

+ " bytes<br/>");

response.getWriter().println("保存完成.<br/>");

}

private void sendCompleteResponse(HttpServletResponse response,

String message) throws IOException {

if (message == null) {

response

.getOutputStream()

.print(

"<html><head><script type='text/javascript'>function killUpdate() { window.parent.killUpdate(''); }</script></head><body onload='killUpdate()'></body></html>");

} else {

response

.getOutputStream()

.print(

"<html><head><script type='text/javascript'>function killUpdate() { window.parent.killUpdate('"

+ message

+ "'); }</script></head><body onload='killUpdate()'></body></html>");

}

private String formatTime(double timeInSeconds) {

long seconds = (long) Math.floor(timeInSeconds);

long minutes = (long) Math.floor(timeInSeconds / 60.0);

long hours = (long) Math.floor(minutes / 60.0);

if (hours != 0) {

return hours + "hours " + (minutes % 60) + "minutes "

+ (seconds % 60) + "seconds";

} else if (minutes % 60 != 0) {

return (minutes % 60) + "minutes " + (seconds % 60) + "seconds";

} else {

return (seconds % 60) + " seconds";

}