Struts2之上传与下载
Struts2之上传与下载
- 1、文件上传
-
- 1.1、commons-fileupload组件
- 1.2、单文件上传
- 1.3、多文件上传
- 1.4、文件下载
-
- 1.4.1、Stream结果类型
- 1.4.2、下载实例
1、文件上传
1.1、commons-fileupload组件
Commons是Apache开放源代码组织的一个Java子项目，其中的FileUpload是用来处理HTTP文件上传的子项目。
组件特点：
- 使用简单：可以方便地嵌入到JSP文件中，编写少量的代码即可完成文件的上传功能。
- 能够全程控制上传的内容。
- 能够对上传文件的大小、类型进行控制。
注意：在Struts2中，struts-core依赖已经包含commons-fileupload组件的相关依赖，所以在struts2的项目中无需额外再导入commons-fileupload组件的相关依赖。
1.2、单文件上传
（1）页面
创建上传页面upload.jsp：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>文件上传页面title>
head>
<body>
<form action="upload.action" method="post" enctype="multipart/form-data">
<div>
<label>选择文件：label>
<input type="file" name="upload"/>
div><br>
<div>
<input type="submit" value="点击上传" />
div>
form>
body>
html>
注意：form表单必须设置enctype="multipart/form-data"属性且提交方式为post。
创建success.jsp页面，为上传成功后的跳转页面。
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>success!title>
head>
<body>
<h1>文件上传成功！h1>
body>
html>
（2）Action控制器
创建上传控制器UploadAction，在Action控制器中需要提供3个成员变量：文件、文件类型、文件名称。如下：
public class UploadAction extends ActionSupport {
private static final long serialVersionUID = 1L;
// 文件对象，与name值保持一致
private File upload;
// 文件类型，为name属性值 + ContentType
private String uploadContentType;
// 文件名称，为name属性值 + FileName
private String uploadFileName;
public File getUpload() {
return upload;
}
public void setUpload(File upload) {
this.upload = upload;
}
public String getUploadContentType() {
return uploadContentType;
}
public void setUploadContentType(String uploadContentType) {
this.uploadContentType = uploadContentType;
}
public String getUploadFileName() {
return uploadFileName;
}
public void setUploadFileName(String uploadFileName) {
this.uploadFileName = uploadFileName;
}
/**
*
* @Title: uploadByIO
* @Description: IO流上传
* @Author: yanchengzhi
* @param: @return
* @return: String
* @throws
*/
public String uploadByIO() {
showFileInfo();
String path = "E:/upload";
InputStream in = null;
OutputStream on = null;
try {
in = new FileInputStream(upload);
on = new FileOutputStream(path + "/" + uploadFileName);
IOUtils.copy(in, on);
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
in.close();
on.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return SUCCESS;
}
/**
* 简单方式上传
* @Title: uploadSimple
* @Description: TODO(描述这个方法的作用)
* @Author: yanchengzhi
* @param: @return
* @return: String
* @throws
*/
public String uploadSimple() {
showFileInfo();
String path = "E:/upload";
String realPath = path + File.separator +uploadFileName;
try {
FileUtils.copyFile(upload, new File(realPath));
} catch (Exception e) {
e.printStackTrace();
}
return SUCCESS;
}
private void showFileInfo() {
System.out.println("文件大小：" + upload.length() / 1024 + "KB");
System.out.println("文件名称：" + uploadFileName);
System.out.println("文件类型：" + uploadContentType);
}
}
（3）struts.xml配置
<package name="upload" extends="default">
<action name="upload" class="com.ycz.struts01.action.UploadAction" method="uploadSimple">
<result>/success.jspresult>
action>
package>
注意：如果要上传的文件大小超过2M，需要配置最大文件限制，否则上传会出错。
（4）测试
启动项目，访问http://localhost:8081/struts01/upload.jsp：
选择文件上传，点击上传按钮，页面跳转：
控制台打印：
查看E盘下的upload目录：
文件上传成功。
1.3、多文件上传
多文件上传和单文件上传本质上是一样的，只不过Action里单文件是用对象接收，而多文件是用数组来接收的，直接在上面的基础上进行修改。
（1）修改upload.jsp页面
<form action="upload.action" method="post" enctype="multipart/form-data">
<div>
<label>选择文件一：label>
<input type="file" name="upload"/>
div><br>
<div>
<label>选择文件二：label>
<input type="file" name="upload"/>
div><br>
<div>
<label>选择文件三：label>
<input type="file" name="upload"/>
div><br>
<div>
<input type="submit" value="点击上传" />
div>
form>
（2）修改UploadAction控制器
public class UploadAction extends ActionSupport {
private static final long serialVersionUID = 1L;
// 文件
private File[] upload;
// 文件类型
private String[] uploadContentType;
// 文件名称
private String[] uploadFileName;
public File[] getUpload() {
return upload;
}
public void setUpload(File[] upload) {
this.upload = upload;
}
public String[] getUploadContentType() {
return uploadContentType;
}
public void setUploadContentType(String[] uploadContentType) {
this.uploadContentType = uploadContentType;
}
public String[] getUploadFileName() {
return uploadFileName;
}
public void setUploadFileName(String[] uploadFileName) {
this.uploadFileName = uploadFileName;
}
/**
*
* @Title: uploadByIO
* @Description: IO流上传
* @Author: yanchengzhi
* @param: @return
* @return: String
* @throws
*/
public String uploadByIO() {
String path = "E:/upload";
InputStream in = null;
OutputStream on = null;
for(int i=0;i<upload.length;i++) {
try {
in = new FileInputStream(upload[i]);
on = new FileOutputStream(path + "/" + uploadFileName);
IOUtils.copy(in, on);
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
in.close();
on.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return SUCCESS;
}
/**
* 简单方式上传
* @Title: uploadSimple
* @Description: TODO(描述这个方法的作用)
* @Author: yanchengzhi
* @param: @return
* @return: String
* @throws
*/
public String uploadSimple() {
String path = "E:/upload";
for(int i=0;i<upload.length;i++) {
String realPath = path + File.separator +uploadFileName[i];
try {
FileUtils.copyFile(upload[i], new File(realPath));
} catch (Exception e) {
e.printStackTrace();
}
}
return SUCCESS;
}
}
（3）测试
启动项目，访问http://localhost:8081/struts01/upload.jsp：
选择多个文件点击上传，页面跳转：
查看E盘upload目录：
多文件上传成功。
1.4、文件下载
1.4.1、Stream结果类型
1.4.2、下载实例
下载上面上传成功的文件。
（1）down.jsp页面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>下载页面title>
head>
<body>
<a href="download.action?fileName=人间美食客.xmind">人间美食客.xmind下载a><br>
<a href="download.action?fileName=设计文档.docx">设计文档.docx下载a><br>
body>
html>
（2）DownAction控制器
public class DownloadAction extends ActionSupport {
private static final long serialVersionUID = 1L;
// 输入流，读取文件
private InputStream inputStream;
// 文件名称
private String fileName;
public InputStream getInputStream() {
return inputStream;
}
public void setInputStream(InputStream inputStream) {
this.inputStream = inputStream;
}
public String getFileName() {
return fileName;
}
public void setFileName(String fileName) {
this.fileName = fileName;
}
public String download() {
try {
String path = "E:/upload/" + fileName;
// 设置中文编码
fileName = URLEncoder.encode(fileName, "UTF-8");
// 初始化流
inputStream = new BufferedInputStream(new FileInputStream(path));
} catch (Exception e) {
e.printStackTrace();
}
return SUCCESS;
}
}
（3）struts.xml配置
<package name="download" extends="default">
<action name="download" class="com.ycz.struts01.action.DownloadAction" method="download">
<result name="success" type="stream">
<param name="contentType">application/octet-streamparam>
<param name="inputName">inputStreamparam>
<param name="contentDisposition">attachment;filename="${fileName}"param>
<param name="bufferSize">4096param>
result>
action>
package>
注意：在result里需要配置下载类型，指定流对象，设置下载形式，设置缓冲区大小等。
（4）测试
启动项目，访问http://localhost:8081/struts01/down.jsp页面：
分别点击两个下载链接：
