Struts基础学习-文件上传与下载

文件上传

简单文件上传

jsp页面

<s:form action="uploadPro" enctype="multipart/form-data">
<s:textfield name="title" label="文件标题" /><br/>
<s:file name="upload" label="选择文件" /><br />
<s:submit value="上传" />
</s:form>

action文件

public class UploadAction extends ActionSupport{
private String title;
private File upload;
//上传文件类型
private String uploadContentType;
//上传文件名
private String uploadFileName;
//配置文件保存属性
private String savePath;
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
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;
}
public String getSavePath() {
return ServletActionContext.getServletContext().getRealPath("/WEB-INF/"+savePath);
}
public void setSavePath(String savePath) {
this.savePath = savePath;
}

public String execute() throws Exception{
FileOutputStream fos=new FileOutputStream(getSavePath()+"\\"+getUploadFileName());
FileInputStream fis=new FileInputStream(getUpload());
byte[] buffer=new byte[1024];
int len=0;
while((len=fis.read(buffer))>0){
fos.write(buffer,0,len);
}
return SUCCESS;
}

}

配置文件

<action name="uploadPro" class="app.action.UploadAction">
<param name="savePath">/upload</param>
<result name="success">/welcome.jsp</result>
</action>

Struts上传文件还是比较简单，只需要在action中申明File属性与其关联，即可。

文件过滤

手动过滤

JAVA文件中

public void validate(){
String filterResult=filterTypes(getAllowTypes().split(","));
if(filterResult!=null){
addFieldError("upload", "上传文件类型不正确");
}
}

public String filterTypes(String[] types){
String fileType=getUploadContentType();
for(String type:types){
if(type.equals(fileType)){
return null;
}
}
return ERROR;
}

并在配置文件中配置类型

<action name="uploadPro" class="app.action.UploadAction">
<param name="savePath">/upload</param>
<param name="allowTypes">image/png,image/gif,img/jpeg</param>
<result name="success">/welcome.jsp</result>
<result name="error">/error.jsp</result>
<result name="input">/input.jsp</result>
</action>

如果没通过校验，则在input.jsp页面中通过<s:fielderror />输出异常信息。

拦截器过滤

<action name="uploadPro" class="app.action.UploadAction">
<!-- 配置fileUpload的拦截器 -->
<interceptor-ref name="fileUpload">
<param name="allowedTypes">image/png,image/gif,img/jpeg,img/jpg</param>
<!-- 单位为字节 -->
<param name="maximumSize">200</param>
</interceptor-ref>
<!-- 配置系统默认的拦截器 -->
<interceptor-ref name="defaultStack" />
<param name="savePath">/upload</param>
<result name="success">/welcome.jsp</result>
<result name="error">/error.jsp</result>
<result name="input">/input.jsp</result>
</action>

在配置文件配置即可。

在过滤文件时，必须显示配置默认的拦截器 defaultStack 并且fileUplaod拦截器必须在defaultStack之前。

文件下载

简单下载实例

public class FileDownAction extends ActionSupport{
private String inputPath;

public String getInputPath() {
return inputPath;
}

public void setInputPath(String inputPath) {
this.inputPath = inputPath;
}

public InputStream getTargetFile(){
return ServletActionContext.getServletContext().getResourceAsStream(inputPath);
}
}

<action name="download" class="app.action.FileDownAction">
<!-- 指定文件下载地址 -->
<param name="inputPath">\images\权限管理功能说明.doc</param>
<result name="success" type="stream">
<!-- 指定文件下载类型 -->
<param name="contentType">doc</param>
<!-- 返回下载文件的信息 -->
<param name="inputName">targetFile</param>
<param name="contentDisposition">filename="sfsfsfs.doc"</param>
<!-- 指定文件缓冲大小 -->
<param name="bufferSize">4096</param>
</result>
</action>