valums file-uploader: js文件上传组件

valums file-uploader 是一个小巧的文件上传插件。

使用XHR,支持多文件上传，并有进度条（ FF3.6+, Safari4+, Chrome，如果不行其它浏览器中将用iframe）。因此，它能提供很好的用户体验。

点击这里Demo。

特色

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多文件上传，进度条

在FF, Chrome中支持拖拽(drag-and-drop)

支持取消

不依赖其它插件

无 Flash

在https下同样有效

在 FF, Chrome, Safari支持快捷键

测试通过： IE7,8; Firefox 3,3.6,4; Safari4,5; Chrome; Opera10.60

License

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This plugin is open sourced under GNU GPL 2 or later and GNU LGPL 2 or later. If this license doesn't suit you mail
me at andrew (at) valums.com.

最简单的示例

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<div id="file-uploader">
<noscript>
<p>Please enable JavaScript to use file uploader.</p>
<!-- or put a simple form for upload here -->
</noscript>
</div>
<script src="fileuploader.js" type="text/javascript"></script>
<script>
function createUploader(){
var uploader = new qq.FileUploader({
element: document.getElementById('file-uploader'),
action: 'FileUploadServlet'
});
}
window.onload = createUploader;
</script>

其它选项

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// url应该在同一域名下
action: '/server/upload',
// 通过url传递的参数，名值对
params: {},

// 限制文件格式
// ex. ['jpg', 'jpeg', 'png', 'gif'] or [ ]
allowedExtensions: [ ],
// 限制文件大小，部分浏览器支持
sizeLimit: 0, // 最大值
minSizeLimit: 0, // 最小值

// 如果为true，服务器的输出将定向到控制台
debug: false,

// 事件处理，return false则中断提交
onSubmit: function(id, fileName){},
onProgress: function(id, fileName, loaded, total){ },
onComplete: function(id, fileName, responseJSON){ },
onCancel: function(id, fileName){},

messages: {
// error messages, see qq.FileUploaderBasic for content
},
showMessage: function(message){ alert(message); }

实例方法

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添加参数

setParams(newParams)

发送额外的参数

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要向服务器传递参数，使用params。

var uploader = new qq.FileUploader({
element: document.getElementById('file-uploader'),
action: '/server-side.upload',
// additional data to send, name-value pairs
params: {
param1: 'value1',
param2: 'value2'
}
});

如果要根据状态改变参数，使用

uploader.setParams({
anotherParam: 'value'
});

在 onSubmit 回调函数中可以放心的使用.

本文由尤慕译自这里。

下面是译者写的一个接收文件上传的Servlet，只要在web.xml中正确配置即可。

package org.aaron.upload;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;

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

public class FileUploadServlet extends HttpServlet {

private static final long serialVersionUID = 6748857432950840322L;
private static final String DIR_PATH = "d:/upload";

@Override
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException {

PrintWriter writer = null;
InputStream is = null;// 上传文件的输入流
FileOutputStream fos = null;// 上传文件的输出流

String filename = request.getHeader("X-File-Name");

try {
writer = response.getWriter();
filename = URLDecoder.decode(filename, "utf-8");
System.out.println("文件名：" + filename);

is = request.getInputStream();
fos = new FileOutputStream(new File(DIR_PATH, filename));
byte[] bytes = new byte[1024];// 存放读取的文件数据
int len = is.read(bytes);
while (len > 0) {
fos.write(bytes, 0, len);// 将读取的数据写入到输出流
len = is.read(bytes);// 继续读取只到读完
}
response.setStatus(HttpServletResponse.SC_OK);
writer.print("{success: true}");
} catch (UnsupportedEncodingException ex) {
log(FileUploadServlet.class.getName() + "has thrown an exception: "
+ ex.getMessage());
} catch (FileNotFoundException ex) {
response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
writer.print("{success: false}");
log(FileUploadServlet.class.getName() + "has thrown an exception: "
+ ex.getMessage());
} catch (IOException ex) {
response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
writer.print("{success: false}");
log(FileUploadServlet.class.getName() + "has thrown an exception: "
+ ex.getMessage());
} finally {
try {
fos.close();
is.close();
} catch (IOException ignored) {
}
}

writer.flush();
writer.close();
}

}

完。