亚洲国产一区二区三区在线播放,国产精品亚洲综合,久热精品在线视频

Struts2文件上傳以及空指針異常解決

Posted on 2009-09-27 08:54 saobaolu 閱讀(4340) 評論(2) 編輯收藏所屬分類: java基礎與算法

uploadFile.java

package action;
2

import java.io.File;
4

import java.text.DateFormat;
5

import java.text.SimpleDateFormat;
6

import java.util.Date;
7

import java.util.Random;
8

import javax.servlet.ServletContext;
10

import org.apache.commons.io.FileUtils;
12

import org.apache.struts2.util.ServletContextAware;
13

import com.opensymphony.xwork2.ActionSupport;
15

public class uploadFile extends ActionSupport implements ServletContextAware {
17

private static final long serialVersionUID = -5016873153441103539L;
19

private File doc;
21

private String fileName;
22

private String contentType;
23

private ServletContext context;
25

public void setDoc(File file) {
27

this.doc = file;
28

}
29

public void setDocFileName(String fileName) {
31

this.fileName = fileName;
32

}
33

public void setDocContentType(String contentType) {
35

this.contentType = contentType;
36

}
37

public void setServletContext(ServletContext context) {
39

this.context = context;
40

}
41

public String execute() throws Exception {
43

String targetDirectory = context.getRealPath("/upload");
44

String targetFileName = generateFileName(fileName);
45

File target = new File(targetDirectory, targetFileName);
46

FileUtils.copyFile(doc, target);
48

return SUCCESS;
50

}
51

private String generateFileName(String fileName) {
53

DateFormat format = new SimpleDateFormat("yyMMddHHmmss");
54

String formatDate = format.format(new Date());
55

int random = new Random().nextInt(10000);
57

int position = fileName.lastIndexOf(".");
59

String extension = fileName.substring(position);
60

return formatDate + random + extension;
62

}
63

}
64

struts.xml

<?xml version="1.0" encoding="UTF-8" ?>
2

<!DOCTYPE struts PUBLIC
3

"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
4

"http://struts.apache.org/dtds/struts-2.0.dtd">
5

<struts>
6

<package name="uploadFile" extends="struts-default">
7

<action name="uploadFile" class="action.uploadFile">
8

<result>/jsp/up.jsp</result>
9

</action>
10

</package>
11

</struts>

web.xml(Struts2的xml，非上傳的xml)

<?xml version="1.0" encoding="UTF-8"?>
2

<web-app version="2.4"
3

xmlns="http://java.sun.com/xml/ns/j2ee"
4

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
5

xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
6

http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
7

<filter>
8

<filter-name>struts2</filter-name>
9

<filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
10

</filter>
11

<filter-mapping>
12

<filter-name>struts2</filter-name>
13

<url-pattern>/*</url-pattern>
14

</filter-mapping>
15

</web-app>

up.jsp（上傳成功頁面）

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
2

<%@ taglib prefix="s" uri = "/struts-tags" %>
3

<%
4

String path = request.getContextPath();
5

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
6

%>
7

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
9

<html>
10

<head>
11

<base href="<%=basePath%>">
12

<title>My JSP 'up.jsp' starting page</title>
14

<!--
21

-->
23

</head>
25

<body>
27

<s:property value="contentType"/><br />
28

<s:property value="dir" /><br />
29

</body>
30

</html>
31

上傳頁面：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
2

<%@ taglib prefix="s" uri="/struts-tags" %>
3

<%
4

String path = request.getContextPath();
5

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
6

%>
7

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
9

<html>
10

<head>
11

<base href="<%=basePath%>">
12

<title>最新產品發布頁</title>
14

<!--
21

-->
23

</head>
25

<body>
27

<s:form action="uploadFile" method="post" enctype="multipart/form-data">
28

<s:file name = "doc" label="上傳視頻" />
29

<s:submit value="上傳" />
30

</s:form>
31

</body>
32

</html>
33

很容易就會報錯，空指針異常。
原因在于上傳頁面<s:file name="這里面的值與action的值不匹配" />
可是我上傳成功之后，up.jsp頁面沒有傳入任何值，郁悶了～
新手，多指點指點，謝謝～

沒有所謂的命運，只有不同的選擇！

騷包路技術菜

Struts2文件上傳以及空指針異常解決

公告

留言簿

我參與的團隊

隨筆分類

隨筆檔案

java

搜索

積分與排名

最新評論