Flex+Java Servlet文件上传实例

资源都是来自网上。本实例将展示使用Flex和java servlet上传文件。
事前准备就是到http://commons.apache.org下载common-fileupload-1.1.1.jar以及common-io-1.2.jar两个包。
前台Flex代码：

Java代码
1.<?xml version="1.0" encoding="utf-8"?>  
2.<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" xmlns="*" creationComplete="init();">  
3.<mx:Script>  
4.<![CDATA[  
5.import flash.net.FileReference;  
6.import mx.controls.Alert;  
7.import mx.events.CloseEvent;  
8.import flash.events.*;  
9. 
10.private var file: FileReference;  
11. 
12.private function init(): void{  
13.Security.allowDomain("*");  
14.file = new FileReference();  
15.file.addEventListener(ProgressEvent.PROGRESS, onProgress);  
16.file.addEventListener(Event.SELECT, onSelect);  
17.file.addEventListener(Event.COMPLETE, completeHandle);  
18.}  
19. 
20.private function completeHandle(event:Event):void{  
21.    Alert.show("恭喜你，上传成功");  
22.}  
23. 
24.private function upload(): void{  
25.var imageTypes:FileFilter = new FileFilter("Images (*.jpg, *.jpeg, *.png)", "*.jpg;*.jpeg;*.png");  
26.var allTypes:Array = new Array(imageTypes);  
27.file.browse(allTypes);  
28.file.browse();  
29.}  
30.private function onSelect(e: Event): void{  
31.Alert.show("上传 " + file.name + " (共 "+Math.round(file.size)+" 字节)?",  
32."确认上传",  
33.Alert.YES|Alert.NO,  
34.null,  
35.proceedWithUpload);  
36.}  
37. 
38.private function onProgress(e: ProgressEvent): void{  
39.lbProgress.text = " 已上传 " + e.bytesLoaded  
40.+ " 字节，共 " + e.bytesTotal + " 字节";  
41.var proc: uint = e.bytesLoaded / e.bytesTotal * 100;  
42.bar.setProgress(proc, 100);  
43.bar.label= "当前进度: " + " " + proc + "%";  
44.}  
45. 
46.private function proceedWithUpload(e: CloseEvent): void{  
47.if (e.detail == Alert.YES){  
48.var request: URLRequest = new URLRequest("http://localhost:8080/FileUploaded/FileUploaded");  
49.try {  
50.file.upload(request);  
51.} catch (error:Error) {  
52.trace("上传失败");  
53.}  
54. 
55.}  
56.}  
57.]]>  
58.</mx:Script>  
59. 
60.<mx:Canvas width="100%" height="100%" x="10" y="170" fontSize="15">  
61.<mx:VBox width="100%" horizontalAlign="center">  
62.<mx:Label id="lbProgress" text="上传"/>  
63.<mx:ProgressBar id="bar" labelPlacement="bottom" themeColor="#F20D7A" 
64.minimum="0" visible="true" maximum="100" label="当前进度: 0%" 
65.direction="right" mode="manual" width="200"/>  
66. 
67.<mx:Button label="上传文件" click="upload();"/>  
68.</mx:VBox>  
69.</mx:Canvas>  
70.</mx:Application> 
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" xmlns="*" creationComplete="init();">
<mx:Script>
<![CDATA[
import flash.net.FileReference;
import mx.controls.Alert;
import mx.events.CloseEvent;
import flash.events.*;

private var file: FileReference;

private function init(): void{
Security.allowDomain("*");
file = new FileReference();
file.addEventListener(ProgressEvent.PROGRESS, onProgress);
file.addEventListener(Event.SELECT, onSelect);
file.addEventListener(Event.COMPLETE, completeHandle);
}

private function completeHandle(event:Event):void{
    Alert.show("恭喜你，上传成功");
}

private function upload(): void{
var imageTypes:FileFilter = new FileFilter("Images (*.jpg, *.jpeg, *.png)", "*.jpg;*.jpeg;*.png");
var allTypes:Array = new Array(imageTypes);
file.browse(allTypes);
file.browse();
}
private function onSelect(e: Event): void{
Alert.show("上传 " + file.name + " (共 "+Math.round(file.size)+" 字节)?",
"确认上传",
Alert.YES|Alert.NO,
null,
proceedWithUpload);
}

private function onProgress(e: ProgressEvent): void{
lbProgress.text = " 已上传 " + e.bytesLoaded
+ " 字节，共 " + e.bytesTotal + " 字节";
var proc: uint = e.bytesLoaded / e.bytesTotal * 100;
bar.setProgress(proc, 100);
bar.label= "当前进度: " + " " + proc + "%";
}

private function proceedWithUpload(e: CloseEvent): void{
if (e.detail == Alert.YES){
var request: URLRequest = new URLRequest("http://localhost:8080/FileUploaded/FileUploaded");
try {
file.upload(request);
} catch (error:Error) {
trace("上传失败");
}

}
}
]]>
</mx:Script>

<mx:Canvas width="100%" height="100%" x="10" y="170" fontSize="15">
<mx:VBox width="100%" horizontalAlign="center">
<mx:Label id="lbProgress" text="上传"/>
<mx:ProgressBar id="bar" labelPlacement="bottom" themeColor="#F20D7A"
minimum="0" visible="true" maximum="100" label="当前进度: 0%"
direction="right" mode="manual" width="200"/>

<mx:Button label="上传文件" click="upload();"/>
</mx:VBox>
</mx:Canvas>
</mx:Application>

http://localhost:8080/FileUploaded/FileUploaded就是你自己写的servlet的路径了。

接下来写的是Java Servlet:

Java代码
1.package upload;  
2.import java.io.File;  
3.import java.io.IOException;  
4.import java.io.PrintWriter;  
5.import java.util.Iterator;  
6.import java.util.List;  
7. 
8.import javax.servlet.ServletException;  
9.import javax.servlet.http.HttpServlet;  
10.import javax.servlet.http.HttpServletRequest;  
11.import javax.servlet.http.HttpServletResponse;  
12. 
13.import org.apache.commons.fileupload.FileItem;  
14.import org.apache.commons.fileupload.FileUploadException;  
15.import org.apache.commons.fileupload.disk.DiskFileItemFactory;  
16.import org.apache.commons.fileupload.servlet.ServletFileUpload;  
17. 
18./** 
19. * 
20. * @author crystal 
21. */ 
22.public class FileUploaded extends HttpServlet {  
23. 
24.    /** 
25.     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods. 
26.     * @param request servlet request 
27.     * @param response servlet response 
28.     */ 
29.    // 定义文件的上传路径  
30. 
31.    private String uploadPath = "d:\\a\\";  
32. 
33.// 限制文件的上传大小  
34. 
35.    private int maxPostSize = 100 * 1024 * 1024;  
36. 
37.    public FileUploaded() {  
38.        super();  
39.    }  
40. 
41.    public void destroy() {  
42.        super.destroy();  
43.    }  
44. 
45.    protected void processRequest(HttpServletRequest request, HttpServletResponse response)  
46.            throws ServletException, IOException {  
47.        System.out.println("Access !");  
48.        response.setContentType("text/html;charset=UTF-8");  
49.        PrintWriter out = response.getWriter();  
50. 
51.//保存文件到服务器中  
52. 
53.        DiskFileItemFactory factory = new DiskFileItemFactory();  
54.        factory.setSizeThreshold(4096);  
55.        ServletFileUpload upload = new ServletFileUpload(factory);  
56.        upload.setSizeMax(maxPostSize);  
57.        try {  
58.            List fileItems = upload.parseRequest(request);  
59.            Iterator iter = fileItems.iterator();  
60.            while (iter.hasNext()) {  
61.                FileItem item = (FileItem) iter.next();  
62.                if (!item.isFormField()) {  
63.                    String name = item.getName();  
64.                    System.out.println(name);  
65.                    try {  
66.                        item.write(new File(uploadPath + name));  
67.                       // SaveFile s = new SaveFile();  
68. 
69.                       // s.saveFile(name);  
70. 
71.                    } catch (Exception e) {  
72.                        e.printStackTrace();  
73.                    }  
74.                }  
75.            }  
76.        } catch (FileUploadException e) {  
77.            e.printStackTrace();  
78.            System.out.println(e.getMessage() + "结束");  
79.        }  
80.    }  
81. 
82.    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">  
83. 
84.    /** 
85.     * Handles the HTTP <code>GET</code> method. 
86.     * @param request servlet request 
87.     * @param response servlet response 
88.     */ 
89.    protected void doGet(HttpServletRequest request, HttpServletResponse response)  
90.            throws ServletException, IOException {  
91.        processRequest(request, response);  
92.    }  
93. 
94.    /** 
95.     * Handles the HTTP <code>POST</code> method. 
96.     * @param request servlet request 
97.     * @param response servlet response 
98.     */ 
99.    protected void doPost(HttpServletRequest request, HttpServletResponse response)  
100.            throws ServletException, IOException {  
101.        processRequest(request, response);  
102.    }  
103. 
104.    /** 
105.     * Returns a short description of the servlet. 
106.     */ 
107.    public String getServletInfo() {  
108.        return "Short description";  
109.    }  
110.    // </editor-fold>  
111. 
112.} 
package upload;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
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;

/**
*
* @author crystal
*/
public class FileUploaded extends HttpServlet {

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     */
    // 定义文件的上传路径

    private String uploadPath = "d:\\a\\";

// 限制文件的上传大小

    private int maxPostSize = 100 * 1024 * 1024;

    public FileUploaded() {
        super();
    }

    public void destroy() {
        super.destroy();
    }

    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        System.out.println("Access !");
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();

//保存文件到服务器中

        DiskFileItemFactory factory = new DiskFileItemFactory();
        factory.setSizeThreshold(4096);
        ServletFileUpload upload = new ServletFileUpload(factory);
        upload.setSizeMax(maxPostSize);
        try {
            List fileItems = upload.parseRequest(request);
            Iterator iter = fileItems.iterator();
            while (iter.hasNext()) {
                FileItem item = (FileItem) iter.next();
                if (!item.isFormField()) {
                    String name = item.getName();
                    System.out.println(name);
                    try {
                        item.write(new File(uploadPath + name));
                       // SaveFile s = new SaveFile();

                       // s.saveFile(name);

                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        } catch (FileUploadException e) {
            e.printStackTrace();
            System.out.println(e.getMessage() + "结束");
        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">

    /**
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     */
    public String getServletInfo() {
        return "Short description";
    }
    // </editor-fold>

}
如果使得你的Servlet被访问，你还需要在WEB-INF/web.xml 添加如下的xml语句：[在<web-app>中]
Java代码
1.<!-- For file uploaded -->  
2.   <servlet>  
3.        <servlet-name>FileUploaded</servlet-name>  
4.        <servlet-class>upload.FileUploaded</servlet-class>  
5.    </servlet>  
6. 
7.    <servlet-mapping>  
8.        <servlet-name>FileUploaded</servlet-name>  
9.        <url-pattern>/FileUploaded</url-pattern>  
10.    </servlet-mapping> 
<!-- For file uploaded -->
   <servlet>
        <servlet-name>FileUploaded</servlet-name>
        <servlet-class>upload.FileUploaded</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>FileUploaded</servlet-name>
        <url-pattern>/FileUploaded</url-pattern>
    </servlet-mapping>

效果图：