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java struts2入门学习实例－－使用struts2快速实现多个文件上传
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一、错误提示信息配置
昨天说到更改默认错误配置信息，我测试很多遍，一直都不对。下面贴出来，待以后有好方法了再补充吧。
首先新建一个properties文件，这里命名为testupload.properties,内容为：
struts.messages.error.file.too.large=\u6587\u4EF6\u592A\u5927{0} "{1}" "{2}" {3}
struts.messages.error.content.type.not.allowed=\u6587\u4EF6\u7C7B\u578B\u4E0D\u5141\u8BB8! {0} "{1}" "{2}" {3}
struts.messages.error.file.extension.not.allowed=\u4E0D\u5141\u8BB8\u7684\u6269\u5C55\u540D! {0} "{1}" "{2}" {3}
这里将默认提示信息改为中文的。upload.xml中内容如下：
<?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>
<!-- 对上传文件总大小进行设置 -->
<constant name="struts.multipart.maxSize" value="20971520"></constant>
<!-- 错误信息提示 -->
<constant name="struts.custom.i18n.resources" value="testupload"/> <package name="upload" extends="struts-default">
<action name="UploadAction" class="action.UploadAction" method="uploadMethod">
<result name="success" type="dispatcher">
/WEB-INF/upload_success.jsp
</result>
<result name="input" type="dispatcher">
upload.jsp
</result>
<!-- 对系统的拦截器进行设置 -->
<interceptor-ref name="fileUpload">
<!-- 对单个上传文件的大小进行设置,5M -->
<param name="maximumSize">5242880</param>
<!-- 对允许的文件扩展名进行设置,这里以英文逗号隔开 -->
<param name="allowedExtensions">.txt,.xml</param>
<!-- 对允许的文件类型进行设置，这里以英文逗号进行隔开 -->
<param name="allowedTypes">text/plain,text/xml</param>
</interceptor-ref>
<!-- 显示引用默认的拦截器 -->
<interceptor-ref name="defaultStack"></interceptor-ref>
</action>
</package> </struts>
二、多个文件上传
只需要更改upload.jsp中的部分内容即可：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<s:form action="UploadAction" enctype="multipart/form-data" method="POST">
<s:textfield label="上传用户" name="username"/>
<s:file label="上传文件" name="upload" />
<s:file label="上传文件" name="upload" />
<s:file label="上传文件" name="upload" /> <s:submit value="提交"/>
</s:form>
</body>
</html>
结果如下所示：
也可以将UploadAction.java中的file改为数组类型的，如下所示：
package action; import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream; import javax.servlet.ServletContext; import org.apache.struts2.ServletActionContext; import com.opensymphony.xwork2.ActionSupport; /**
* @ClassName: UploadAction
* @Description: 文件上传
* @author: amosli
* @email:amosli@infomorrow.com
* @date Jan 14, 2014 1:50:28 AM
*/
public class UploadAction extends ActionSupport {
private static final long serialVersionUID = -8920466592471253212L;
private String username;// 用户名
private String[] uploadContentType;// 上传文件的类型,(Fileupload拦截器传入的参数)
private File[] upload;// 上传的文件,(Fileupload拦截器传入的参数)
private String[] uploadFileName;// 上传文件的真实文件名，(Fileupload拦截器传入的参数) public void setUsername(String username) {
this.username = username;
} public String[] getUploadContentType() {
return uploadContentType;
} public void setUploadContentType(String[] uploadContentType) {
this.uploadContentType = uploadContentType;
} public File[] getUpload() {
return upload;
} public void setUpload(File[] upload) {
this.upload = upload;
} public String[] getUploadFileName() {
return uploadFileName;
} public void setUploadFileName(String[] uploadFileName) {
this.uploadFileName = uploadFileName;
} public String getUsername() {
return username;
} public String uploadMethod() throws Exception {
ServletContext context = ServletActionContext.getServletContext();
String real_path = context.getRealPath("/WEB-INF/upload/");
for (int i = 0; i < upload.length; i++) {
InputStream inputStream = new FileInputStream(upload[i]);
OutputStream outputStream = new FileOutputStream(real_path + "/" + uploadFileName);
byte[] b = new byte[1024];
int len = 0;
while ((len = inputStream.read(b)) > 0) {
outputStream.write(b, 0, len);
}
// 关闭流
inputStream.close();
outputStream.close();
// 删除tmp文件,最好是用tyrcatch finally进行删除
// upload[i].delete();
} return SUCCESS;
} }
这里没有立马删除是想做个 演示 ，查看一下缓存文件空间生成了几个。
首先，将项目打包，生成war包，这里我用的是mvn package打的包。
其次，将tomcat启动，将成生的war包拷到webapp目录下。
最后，在浏览器演示多个文件上传。
演示结果如下图所示：
1、打开浏览器，上传a.txt,b.txt,c.txt三个文件
2、点击提交后，跳转到成功提示页面
3.查看相对应的文件目录，这里没有删除缓存，所以可以看到三个缓存文件
三、指定文件上传的路径
如何通过配置文件，手动指定文件的上传目录？
首先，在upload.xml中action标签中指定参数名为uploadPath,赋值为/home/amosli/develop/struts2_learn/
<action name="UploadAction" class="action.UploadAction" method="uploadMethod">
<param name="uploadPath">/home/amosli/develop/struts2_learn/</param>
.................
全部的upload.xml文件为：
<?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>
<!-- 对上传文件总大小进行设置 -->
<constant name="struts.multipart.maxSize" value="20971520"></constant>
<!-- 错误信息提示 -->
<constant name="struts.custom.i18n.resources" value="testupload" /> <package name="upload" extends="struts-default">
<action name="UploadAction" class="action.UploadAction" method="uploadMethod">
<param name="uploadPath">/home/amosli/develop/struts2_learn/</param>
<result name="success" type="dispatcher">
/WEB-INF/upload_success.jsp
</result>
<result name="input" type="dispatcher">
upload.jsp
</result>
<!-- 对系统的拦截器进行设置 -->
<interceptor-ref name="fileUpload">
<!-- 对单个上传文件的大小进行设置,5M -->
<param name="maximumSize">5242880</param>
<!-- 对允许的文件扩展名进行设置,这里以英文逗号隔开 -->
<param name="allowedExtensions">.txt,.xml</param>
<!-- 对允许的文件类型进行设置，这里以英文逗号进行隔开 -->
<param name="allowedTypes">text/plain,text/xml</param>
</interceptor-ref>
<!-- 显示引用默认的拦截器 -->
<interceptor-ref name="defaultStack"></interceptor-ref>
</action>
</package>
</struts>
其次，在UploadAction.java中新建一个变量uploadPath,为其设置set方法。同时在uploadMethod方法中将目标文件夹改为uploadPath.
即,UploadAction.java为：
package action; import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream; import com.opensymphony.xwork2.ActionSupport; /**
* @ClassName: UploadAction
* @Description: 文件上传
* @author: amosli
* @email:amosli@infomorrow.com
* @date Jan 14, 2014 1:50:28 AM
*/
public class UploadAction extends ActionSupport {
private static final long serialVersionUID = -8920466592471253212L;
private String username;// 用户名
private String[] uploadContentType;// 上传文件的类型,(Fileupload拦截器传入的参数)
private File[] upload;// 上传的文件,(Fileupload拦截器传入的参数)
private String[] uploadFileName;// 上传文件的真实文件名，(Fileupload拦截器传入的参数)
private String uploadPath; public void setUploadPath(String uploadPath) {
this.uploadPath = uploadPath;
} public void setUsername(String username) {
this.username = username;
} public String[] getUploadContentType() {
return uploadContentType;
} public void setUploadContentType(String[] uploadContentType) {
this.uploadContentType = uploadContentType;
} public File[] getUpload() {
return upload;
} public void setUpload(File[] upload) {
this.upload = upload;
} public String[] getUploadFileName() {
return uploadFileName;
} public void setUploadFileName(String[] uploadFileName) {
this.uploadFileName = uploadFileName;
} public String getUsername() {
return username;
} public String uploadMethod() throws Exception {
// ServletContext context = ServletActionContext.getServletContext();
// String real_path = context.getRealPath("/WEB-INF/upload/");
for (int i = 0; i < upload.length; i++) {
InputStream inputStream = new FileInputStream(upload[i]);
OutputStream outputStream = new FileOutputStream(uploadPath + "/" + uploadFileName[i]);
byte[] b = new byte[1024];
int len = 0;
while ((len = inputStream.read(b)) > 0) {
outputStream.write(b, 0, len);
}
// 关闭流
inputStream.close();
outputStream.close();
// 删除tmp文件,最好是用tyrcatch finally进行删除
// upload[i].delete();
} return SUCCESS;
} }
最后，运行效果如下：
本文源码 :https://github.com/amosli/strut2_learn
