对于struts2一直都是看过，很少去动手写里面的功能，今天花了一点时间算整理整理。
整体的项目大致如下：
1：文件上传
uploadAction.java
package action;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import org.apache.commons.io.FileUtils;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionSupport;
public class UploadAction extends ActionSupport {
private static final long serialVersionUID = -8920466592471253212L;
private String title;
private File file; // 上传的文件
private String fileFileName; // 文件名称
private String fileContentType; // 文件类型
private String savePath;
private String contents = "";
public String execute() throws Exception {
// String url = getSavePath() + File.separator + getFileFileName();
String url = getSavePath();
System.out.println("url==" + url + ",,," + getFileContentType());
FileOutputStream fos = null;
FileInputStream fis = null;
try {
// fos = new FileOutputStream(url);
File uploadFile = new File(url, this.getFileFileName());
fos = new FileOutputStream(uploadFile);
fis = new FileInputStream(getFile());
byte[] buffer = new byte[1024 * 1024];
int len = 0;
while ((len = fis.read(buffer)) > 0) {
fos.write(buffer, 0, len);
setContents(getContents() + new String(buffer));
}
fos.flush();
} catch (Exception e) {
e.printStackTrace();
return INPUT;
} finally {
close(fos, fis);
}
return SUCCESS;
}
public File getFile() {
return file;
}
public void setFile(File file) {
this.file = file;
}
public String getFileFileName() {
return fileFileName;
}
public void setFileFileName(String fileFileName) {
this.fileFileName = fileFileName;
}
public String getFileContentType() {
return fileContentType;
}
public void setFileContentType(String fileContentType) {
this.fileContentType = fileContentType;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getSavePath() {
String result = ServletActionContext.getServletContext().getRealPath(
savePath);
return result;
}
public void setSavePath(String savePath) {
this.savePath = savePath;
}
public String getContents() {
return contents;
}
public void setContents(String contents) {
this.contents = contents;
}
private void close(FileOutputStream fos, FileInputStream fis) {
if (fis != null) {
try {
fis.close();
} catch (IOException e) {
System.out.println("FileInputStream关闭失败");
e.printStackTrace();
}
}
if (fos != null) {
try {
fos.close();
} catch (IOException e) {
System.out.println("FileOutputStream关闭失败");
e.printStackTrace();
}
}
}
}
上传页面upload.jsp：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib prefix="s" uri="/struts-tags" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>上传文件</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
</head>
<body>
<s:form action="uploads" method="post" enctype="multipart/form-data">
<s:textfield id="title" name="title" label="文件标题"/>
<s:file name="file" label="上传文件"/>
<s:submit value="提交"/>
</s:form>
</body>
</html>
上传成功uploadSuccess.jsp：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib prefix="s" uri="/struts-tags" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
</head>
<body>
上传文件：<s:property value="title" /><br/>
文件内容：
<s:if test="%{fileContentType.indexOf('image')>=0}">
<img src="<s:property value="'upload/'+fileFileName"/>"/>
</s:if>
<s:else>
<s:property value="contents"/>
</s:else>
</body>
</html>
主要的struts.xml：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN" "http://struts.apache.org/dtds/struts-2.3.dtd">
<struts>
<constant name="struts.devMode" value="true" />
<constant name="struts.i18n.encoding" value="UTF-8" />
<package name="myDemo" extends="struts-default" namespace="/">
<action name="uploads" class="action.UploadAction" >
<param name="savePath">/upload</param>
<result name="input">/upload.jsp</result>
<result name="success">/uploadSuccess.jsp</result>
</action>
<action name="downloads" class="action.DownloadAction">
<param name="inputPath">upload</param>
<result name="input">/downloadSuccess.jsp</result>
<result name="success" type="stream">
<param name="contentType">application/octet-stream;charset=ISO8859-1 </param>
<param name="inputName">downloadFile</param>
<param name="contentDisposition">attachment;filename="${downloadFileName}"</param>
<param name="bufferSize">4096</param>
</result>
</action>
<action name="download" class="action.DownloadAction" method="download">
<param name="inputPath">upload</param>
<result name="success" >/download.jsp
</result>
</action>
<!-- <action name="*">
<result>/{1}.jsp</result>
</action> -->
</package>
</struts>
对于上传主要在action哩，主要有3个属性：***、***FileName、***ContentTyp。我的例子**为file。
成功后，页面若是图片形式，我把它显示出来，如果不是就显示里面的内容。
2：文件下载
文件下载主要配置在struts.xml里。
一般使用result=“stream” 在struts中进行文件下载
有4个参数：contentType（主要）、contentDisposition（主要）、inputName、bufferSize，相对于这2个主要些。
详细的可以参考这个页面：强烈碰击
常常也会在下载的时候碰到一个异常：Can not find a java.io.InputStream with the name [downloadFile] in the invocation stack. Check the <param name="inputName"> tag specified for this action.
主要为2中情况：
第一：文件路径不对，没有取到文件，只需要在return之前，把流放在system.out.println()中输出一下，是null的话，就是路径不对。
第二：action中需要配置"<param name="inputName">"后面属性的那个get方法。
下载action：downloadAction.java
package action;
import java.io.File;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionSupport;
public class DownloadAction extends ActionSupport {
private static final long serialVersionUID = -5772950074616179246L;
// the download file
private String fileName;
// the download folder
private String inputPath;
// all files of the download folder
private List<String> fileNames;
public String getFileName() {
return fileName;
}
public void setFileName(String fileName) {
//System.out.println("----"+fileName);
try {
fileName = new String(fileName.getBytes("ISO-8859-1"),"UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
//System.out.println("----"+fileName);
this.fileName = fileName;
}
public String getInputPath() {
return inputPath;
}
public void setInputPath(String inputPath) {
this.inputPath = inputPath;
}
public InputStream getDownloadFile() {
String urll = File.separator + inputPath + File.separator + fileName;
InputStream is = ServletActionContext.getServletContext()
.getResourceAsStream(urll);
//System.out.println(urll+"-----"+fileName+"---"+is);
return is;
}
public String getDownloadFileName() {
String downFileName = fileName;
//System.out.println("----"+downFileName);
try {
downFileName = new String(downFileName.getBytes(), "ISO8859-1");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
//System.out.println("----"+downFileName);
return downFileName;
}
public String download() throws Exception {
String downloadDir = ServletActionContext.getServletContext()
.getRealPath(File.separator + inputPath);
File rootFile = new File(downloadDir);
File[] files = rootFile.listFiles();
fileNames = new ArrayList<String>();
for (File f : files) {
if (!f.isDirectory()) {
String name = f.getName();
//System.out.println(name);
fileNames.add(name);
}
}
return SUCCESS;
}
public List<String> getFileNames() {
return fileNames;
}
public void setFileNames(List<String> fileNames) {
this.fileNames = fileNames;
}
}
下载页面download.jsp：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
</head>
<body>
<font color="blue">--------------------------</font>
<br>
<s:iterator value="fileNames" var="file">
<s:set value="file" id="files" name="files" scope="Request"/>
<%
String fname = (String)request.getAttribute("files");
fname = java.net.URLEncoder.encode(fname, "UTF-8");
%>
<a href="downloads.action?fileName=<%=fname %>">
<s:property value="file" />下载
</a>
<br />
</s:iterator>
</body>
</html>
3个乱码的地方：
a：前台中文，后台获取：
public void setFileName(String fileName) {
//System.out.println("----"+fileName);
try {
fileName = new String(fileName.getBytes("ISO-8859-1"),"UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
//System.out.println("----"+fileName);
this.fileName = fileName;
}
在未URLEncoder之前：
b:下载时显示中文名字：
public String getDownloadFileName() {
String downFileName = fileName;
//System.out.println("----"+downFileName);
try {
downFileName = new String(downFileName.getBytes(), "ISO8859-1");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
//System.out.println("----"+downFileName);
return downFileName;
}
<action name="downloads" class="action.DownloadAction">
<param name="inputPath">upload</param>
<result name="input">/downloadSuccess.jsp</result>
<result name="success" type="stream">
<param name="contentType">application/octet-stream;charset=ISO8859-1 </param>
<param name="inputName">downloadFile</param>
<param name="contentDisposition">attachment;filename="${downloadFileName}"</param>
<param name="bufferSize">4096</param>
</result>
</action>
主要为action配置时配置contentDisposition参数，attachment;filename="${downloadFileName}"，
取的就为getDownloadFileName()的值。
c:链接中的中文编码
<s:iterator value="fileNames" var="file">
<s:set value="file" id="files" name="files" scope="Request"/>
<%
String fname = (String)request.getAttribute("files");
fname = java.net.URLEncoder.encode(fname, "UTF-8");
%>
<a href="downloads.action?fileName=<%=fname %>">
<s:property value="file" />下载
</a>
<br />
</s:iterator>
本Demo可以自这里下载到： 惨不忍睹的点击
