1. struts系统中的拦截器介绍
过滤器：javaweb中的服务器组件，主要针对的请求和响应进行拦截。
拦截器：主要针对方法的调用，进行拦截器，当使用代理对象调用某个方法时候
对方法的调用进行拦截，对拦截到的方法可以进行扩展，增强
Struts2中的拦截器主要针对Action中方法的调用进行拦截
1 <interceptors> 2 <!—声明n个拦截器--> 3 <interceptor name="fileUpload" 4 class="org.apache.struts2.interceptor.FileUploadInterceptor" /> 5 <interceptor name="i18n" 6 class="com.opensymphony.xwork2.interceptor.I18nInterceptor" /> 7 <interceptor name="logger" 8 class="com.opensymphony.xwork2.interceptor.LoggingInterceptor" /> 9 <interceptor name="modelDriven" 10 class="com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor" /> 11 <interceptor name="params" 12 class="com.opensymphony.xwork2.interceptor.ParametersInterceptor" /> 13 <interceptor name="staticParams" 14 class="com.opensymphony.xwork2.interceptor.StaticParametersInterceptor" /> 15 <interceptor name="token" 16 class="org.apache.struts2.interceptor.TokenInterceptor" /> 17 <interceptor name="tokenSession" 18 class="org.apache.struts2.interceptor.TokenSessionStoreInterceptor" /> 19 20 <!—由已经声明的n个拦截器，组成拦截器栈--> 21 <interceptor-stack name="defaultStack"> 22 <interceptor-ref name="exception" /> 23 <interceptor-ref name="alias" /> 24 <interceptor-ref name="servletConfig" /> 25 <interceptor-ref name="i18n" /> 26 <interceptor-ref name="prepare" /> 27 <interceptor-ref name="chain" /> 28 <interceptor-ref name="scopedModelDriven" /> 29 <interceptor-ref name="modelDriven" /> 30 <interceptor-ref name="fileUpload" /> 31 <interceptor-ref name="checkbox" /> 32 <interceptor-ref name="multiselect" /> 33 <interceptor-ref name="staticParams" /> 34 <interceptor-ref name="actionMappingParams" /> 35 <interceptor-ref name="params"> 36 <param name="excludeParams">^class\..*,^dojo\..*,^struts\..*,^session\..*,^request\..*,^application\..*,^servlet(Request|Response)\..*,^parameters\..*,^action:.*,^method:.* 37 </param> 38 </interceptor-ref> 39 <interceptor-ref name="conversionError" /> 40 <interceptor-ref name="validation"> 41 <param name="excludeMethods">input,back,cancel,browse</param> 42 </interceptor-ref> 43 <interceptor-ref name="workflow"> 44 <param name="excludeMethods">input,back,cancel,browse</param> 45 </interceptor-ref> 46 <interceptor-ref name="debugging" /> 47 <interceptor-ref name="deprecation" /> 48 </interceptor-stack> 49 </interceptors> 50 <default-interceptor-ref name="defaultStack" /> 51 </package> 52
拦截器栈：
a --> b --> c --> execute() --> c --> b --> a
2.文件上传
2.1 Action
1 /*** 处理文件上传的请求 **/
2 public class FileAction
3 {
4 // org.apache.struts2.interceptor.FileUploadInterceptor
5 // 1 定义文件上传需要的特定属性
6 private File img; // 上传的文件对象
7 private String imgContentType;// 删除的文件的内容的类型
8 private String imgFileName;// 上传的文件名称
9 private String path; // 文件保存到服务器上的目录
10
11 public String getPath()
12 {
13 return path;
14 }
15
16 public void setPath(String path)
17 {
18 this.path = path;
19 }
20
21 public File getImg()
22 {
23 return img;
24 }
25
26 public void setImg(File img)
27 {
28 this.img = img;
29 }
30
31 public String getImgContentType()
32 {
33 return imgContentType;
34 }
35
36 public void setImgContentType(String imgContentType)
37 {
38 this.imgContentType = imgContentType;
39 }
40
41 public String getImgFileName()
42 {
43 return imgFileName;
44 }
45
46 public void setImgFileName(String imgFileName)
47 {
48 this.imgFileName = imgFileName;
49 }
50
51 /*** 处理文件上传的请求 ****/
52 public String uploadFile()
53 {
54 System.out.println(img);
55 System.out.println(imgContentType);
56 System.out.println(imgFileName);
57 // 修改文件名
58 String fname = UUID.randomUUID()
59 + imgFileName.substring(imgFileName.lastIndexOf("."));
60 // 将上传的文件对象img保存到服务器的指定目录
61 // 1获得path的绝对路径
62 String pth = ServletActionContext.getServletContext().getRealPath(path);
63 // 2在pth下创建文件
64 File file = new File(pth, fname);
65 // 3将img内容拷贝file中
66 try
67 {
68 FileUtils.copyFile(img, file);
69 }
70 catch (IOException e)
71 {
72 e.printStackTrace();
73 }
74 return Action.SUCCESS;
75 }
76 }
2.2 struts.xml 配置
1 <?xml version="1.0" encoding="UTF-8"?>
2 <!DOCTYPE struts PUBLIC
3 "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
4 "http://struts.apache.org/dtds/struts-2.3.dtd">
5 <struts>
6 <package name="file" namespace="/" extends="struts-default">
7 <interceptors>
8 <!-- 自定义拦截器栈 -->
9 <interceptor-stack name="mystack">
10 <!-- 引用系统文件上传的拦截器 -->
11 <interceptor-ref name="fileUpload">
12 <param name="allowedExtensions">txt,jpg,doc</param>
13 <!-- 其他属性的赋值同理 -->
14 </interceptor-ref>
15 <!-- 引用系统基本拦截器栈 -->
16 <interceptor-ref name="basicStack" />
17 </interceptor-stack>
18 </interceptors>
19 <action name="fileAction_*" class="com.bjsxt.action.FileAction"
20 method="{1}">
21 <!-- 引用自定义的拦截器栈 -->
22 <interceptor-ref name="mystack"></interceptor-ref>
23 <!-- 给path属性赋值 -->
24 <param name="path">filedir</param>
25 <result>/index.jsp</result>
26 </action>
27 </package>
28 </struts>
2.3实现UI页面
1 <form action="fileAction_uploadFile.action" method="post" 2 enctype="multipart/form-data"> 3 <input type="file" name="img" /> 4 <input type="submit" /> 5 </form>
3.文件下载
3.1 Action
1 //org.apache.struts2.dispatcher.StreamResult
2 public class DownloadAction
3 {
4 private InputStream inputStream;
5 private String fname;// 需要下载的文件的名字
6
7 public InputStream getInputStream()
8 {
9 System.out.println("----------getInputStream");
10 return inputStream;
11 }
12
13 public String getFname()
14 {
15 return fname;
16 }
17
18 public void setFname(String fname)
19 {
20 this.fname = fname;
21 }
22
23 /*** 实现文件下载 ***/
24 public String download()
25 {
26 System.out.println("----------download");
27 // 获得附件的保存目录
28 String path = ServletActionContext.getServletContext().getRealPath(
29 "filedir");
30 // 将下载的文件封装为InputStream的对象
31 try
32 {
33 inputStream = new FileInputStream(path + "/" + fname);
34 }
35 catch (FileNotFoundException e)
36 {
37 // TODO Auto-generated catch block
38 e.printStackTrace();
39 }
40 return Action.SUCCESS;
41 }
42 }
3.2 struts.xml 配置：
1 <package name="down" namespace="/down" extends="struts-default">
2 <action name="downloadAction_*" class="com.bjsxt.action.DownloadAction"
3 method="{1}">
4 <result type="stream">
5 <param name="inputName">inputStream</param>
6 <!-- 指定下载的附件的类型 -->
7 <param name="contentType">application/octet-stream</param>
8 <!-- 指定下载的附件的名称 -->
9 <param name="contentDisposition">attachment;filename=${fname}</param>
10 </result>
11 </action>
12 </package>
时间： 2024-10-13 09:47:07