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";@Overrideprotected 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。