關於Java中上傳文件與下載文件問題-----同樣適用於服務器

一、文件上傳

在進行文件上傳的時候我們需要注意這麼幾個點

1、文件上傳的時候，表單提交的時候。

<s:form action="UpLoadAction" enctype="multipart/form-data" method="post">
		<s:textfield name="title" label="類型"></s:textfield>
		<s:file name="upload" label="文件"></s:file>
		<s:submit value="提交"></s:submit>
</s:form>

2、文件上傳之後，要使用來接受。

private String title;
	private File upload;                //文件
	private String uploadFileName;        //文件名
	private String uploadContentType;    //文件類型
	private String savePath;            //文件路徑
	public String getSavePath() {
		return savePath;
	}
	public void setSavePath(String savePath) {
		this.savePath = 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 getUploadFileName() {
		return uploadFileName;
	}
	public void setUploadFileName(String uploadFileName) {
		this.uploadFileName = uploadFileName;
	}
	public String getUploadContentType() {
		return uploadContentType;
	}
	public void setUploadContentType(String uploadContentType) {
		this.uploadContentType = uploadContentType;
	}
	
	public String execute() throws Exception{
		
		String newName = UUID.randomUUID()+uploadFileName;
		FileOutputStream fos = new FileOutputStream(savePath+"/"+newName);
		FileInputStream fis = new FileInputStream(upload);
		
		byte[] buffer = new byte[1024];
		int len = 0;
		while((len = fis.read(buffer)) > 0) {
			fos.write(buffer,0,len);
		}
		return "success";
	}

3、筆者使用的是Struts2，所以Action配置的時候應該是這樣的

<action name="UpLoadAction" class="Nuc.Test.Action.UpLoadAction">
             <!-- 配置fileUpload攔截器 -->
        	<interceptor-ref name="defaultStack"/>
        	<param name="savePath">e:/Study/Struts</param>
        	<result name="success">/Success.jsp</result>
</action>

二、文件下載的時候

1、文件跳轉（這裏上傳了文件的路徑，名字，類型）

<s:iterator value="list" var="file">
		<a href="DownLoadAction?inputPath=${file.inputPath}&contentType=${file.contentType}&downFileName=${file.downFileName}">${file.downFileName}</a>
		<br>
</s:iterator>

2、後臺處理（其中有很多轉碼問題）

private String inputPath;
	private String contentType;
	private String downFileName;
	public String getInputPath() {
		return inputPath;
	}
	public void setInputPath(String inputPath) throws UnsupportedEncodingException {
		this.inputPath = new String(inputPath.getBytes("iso-8859-1"),"utf-8");
		//this.inputPath = inputPath;
	}
	public String getContentType() {
		return contentType;
	}
	public void setContentType(String contentType) {
		this.contentType = contentType;
	}
	public String getDownFileName() throws UnsupportedEncodingException {
		// ת»»¸ñʽ
		downFileName = URLEncoder.encode(downFileName,"UTF-8");
		return downFileName;
	}
	public void setDownFileName(String downFileName) throws UnsupportedEncodingException {
		this.downFileName = new String(downFileName.getBytes("iso-8859-1"),"utf-8");
		//this.downFileName = downFileName;
	}
	public InputStream getTargetFile() throws FileNotFoundException
	{
		System.out.println(contentType+"###"+downFileName);
		System.out.println(inputPath+"ssssssssssssss");
		InputStream is = new FileInputStream(inputPath);   
		   
		return is;  
	}

3、後臺Aciton書寫

<result name="success" type="stream">
        		<param name="contentType">${contentType}</param>
        		<param name="inputName">targetFile</param>
        		<param name="contentDisposition">attachment;filename="${downFileName}"</param>
</result>