java下载文件的路径

‘壹’ java 怎么从ftp获取文件路径

拿去用吧。

packagecom.weixin.util;

importjava.io.File;
importjava.io.FileOutputStream;
importjava.io.IOException;
importjava.io.InputStream;
importjava.io.OutputStream;
importjava.io.PrintWriter;
importjava.io.RandomAccessFile;

importorg.apache.commons.net.PrintCommandListener;
importorg.apache.commons.net.ftp.FTP;
importorg.apache.commons.net.ftp.FTPClient;
importorg.apache.commons.net.ftp.FTPFile;
importorg.apache.commons.net.ftp.FTPReply;

importcom.weixin.constant.DownloadStatus;
importcom.weixin.constant.UploadStatus;

/**
*支持断点续传的FTP实用类
*@version0.1实现基本断点上传下载
*@version0.2实现上传下载进度汇报
*@version0.3实现中文目录创建及中文文件创建，添加对于中文的支持
*/
publicclassContinueFTP{
	publicFTPClientftpClient=newFTPClient();
	
	publicContinueFTP(){
		//设置将过程中使用到的命令输出到控制台
		this.ftpClient.addProtocolCommandListener(newPrintCommandListener(newPrintWriter(System.out)));
	}
	
	/**
	*连接到FTP服务器
	*@paramhostname主机名
	*@paramport端口
	*@paramusername用户名
	*@parampassword密码
	*@return是否连接成功
	*@throwsIOException
	*/
	publicbooleanconnect(Stringhostname,intport,Stringusername,Stringpassword)throwsIOException{
		ftpClient.connect(hostname,port);
		ftpClient.setControlEncoding("GBK");
		if(FTPReply.isPositiveCompletion(ftpClient.getReplyCode())){
			if(ftpClient.login(username,password)){
				returntrue;
			}
		}
		disconnect();
		returnfalse;
	}
	
	/**
	*从FTP服务器上下载文件,支持断点续传，上传百分比汇报
	*@paramremote远程文件路径
	*@paramlocal本地文件路径
	*@return上传的状态
	*@throwsIOException
	*/
	publicDownloadStatusdownload(Stringremote,Stringlocal)throwsIOException{
		//设置被动模式
		ftpClient.enterLocalPassiveMode();
		//设置以二进制方式传输
		ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
		DownloadStatusresult;
		
		//检查远程文件是否存在
		FTPFile[]files=ftpClient.listFiles(newString(remote.getBytes("GBK"),"iso-8859-1"));
		if(files.length!=1){
			System.out.println("远程文件不存在");
			returnDownloadStatus.Remote_File_Noexist;
		}
		
		longlRemoteSize=files[0].getSize();
		Filef=newFile(local);
		//本地存在文件，进行断点下载
		if(f.exists()){
			longlocalSize=f.length();
			//判断本地文件大小是否大于远程文件大小
			if(localSize>=lRemoteSize){
				System.out.println("本地文件大于远程文件，下载中止");
				returnDownloadStatus.Local_Bigger_Remote;
			}
			
			//进行断点续传，并记录状态
			FileOutputStreamout=newFileOutputStream(f,true);
			ftpClient.setRestartOffset(localSize);
			InputStreamin=ftpClient.retrieveFileStream(newString(remote.getBytes("GBK"),"iso-8859-1"));
			byte[]bytes=newbyte[1024];
			longstep=lRemoteSize/100;
			longprocess=localSize/step;
			intc;
			while((c=in.read(bytes))!=-1){
				out.write(bytes,0,c);
				localSize+=c;
				longnowProcess=localSize/step;
				if(nowProcess>process){
					process=nowProcess;
					if(process%10==0)
						System.out.println("下载进度："+process);
					//TODO更新文件下载进度,值存放在process变量中
				}
			}
			in.close();
			out.close();
			booleanisDo=ftpClient.completePendingCommand();
			if(isDo){
				result=DownloadStatus.Download_From_Break_Success;
			}else{
				result=DownloadStatus.Download_From_Break_Failed;
			}
		}else{
			OutputStreamout=newFileOutputStream(f);
			InputStreamin=ftpClient.retrieveFileStream(newString(remote.getBytes("GBK"),"iso-8859-1"));
			byte[]bytes=newbyte[1024];
			longstep=lRemoteSize/100;
			longprocess=0;
			longlocalSize=0L;
			intc;
			while((c=in.read(bytes))!=-1){
				out.write(bytes,0,c);
				localSize+=c;
				longnowProcess=localSize/step;
				if(nowProcess>process){
					process=nowProcess;
					if(process%10==0)
						System.out.println("下载进度："+process);
					//TODO更新文件下载进度,值存放在process变量中
				}
			}
			in.close();
			out.close();
			booleanupNewStatus=ftpClient.completePendingCommand();
			if(upNewStatus){
				result=DownloadStatus.Download_New_Success;
			}else{
				result=DownloadStatus.Download_New_Failed;
			}
		}
		returnresult;
	}
	
	/**
	*上传文件到FTP服务器，支持断点续传
	*@paramlocal本地文件名称，绝对路径
	*@paramremote远程文件路径，使用/home/directory1/subdirectory/file.ext按照Linux上的路径指定方式，支持多级目录嵌套，支持递归创建不存在的目录结构
	*@return上传结果
	*@throwsIOException
	*/
	publicUploadStatusupload(Stringlocal,Stringremote)throwsIOException{
		//设置PassiveMode传输
		ftpClient.enterLocalPassiveMode();
		//设置以二进制流的方式传输
		ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
		ftpClient.setControlEncoding("GBK");
		UploadStatusresult;
		//对远程目录的处理
		StringremoteFileName=remote;
		if(remote.contains("/")){
			remoteFileName=remote.substring(remote.lastIndexOf("/")+1);
			//创建服务器远程目录结构，创建失败直接返回
			if(CreateDirecroty(remote,ftpClient)==UploadStatus.Create_Directory_Fail){
				returnUploadStatus.Create_Directory_Fail;
			}
		}
		
		//检查远程是否存在文件
		FTPFile[]files=ftpClient.listFiles(newString(remoteFileName.getBytes("GBK"),"iso-8859-1"));
		if(files.length==1){
			longremoteSize=files[0].getSize();
			Filef=newFile(local);
			longlocalSize=f.length();
			if(remoteSize==localSize){
				returnUploadStatus.File_Exits;
			}elseif(remoteSize>localSize){
				returnUploadStatus.Remote_Bigger_Local;
			}
			
			//尝试移动文件内读取指针,实现断点续传
			result=uploadFile(remoteFileName,f,ftpClient,remoteSize);
			
			//如果断点续传没有成功，则删除服务器上文件，重新上传
			if(result==UploadStatus.Upload_From_Break_Failed){
				if(!ftpClient.deleteFile(remoteFileName)){
					returnUploadStatus.Delete_Remote_Faild;
				}
				result=uploadFile(remoteFileName,f,ftpClient,0);
			}
		}else{
			result=uploadFile(remoteFileName,newFile(local),ftpClient,0);
		}
		returnresult;
	}
	/**
	*断开与远程服务器的连接
	*@throwsIOException
	*/
	publicvoiddisconnect()throwsIOException{
		if(ftpClient.isConnected()){
			ftpClient.disconnect();
		}
	}
	
	/**
	*递归创建远程服务器目录
	*@paramremote远程服务器文件绝对路径
	*@paramftpClientFTPClient对象
	*@return目录创建是否成功
	*@throwsIOException
	*/
	(Stringremote,FTPClientftpClient)throwsIOException{
		UploadStatusstatus=UploadStatus.Create_Directory_Success;
		Stringdirectory=remote.substring(0,remote.lastIndexOf("/")+1);
		if(!directory.equalsIgnoreCase("/")&&!ftpClient.changeWorkingDirectory(newString(directory.getBytes("GBK"),"iso-8859-1"))){
			//如果远程目录不存在，则递归创建远程服务器目录
			intstart=0;
			intend=0;
			if(directory.startsWith("/")){
				start=1;
			}else{
				start=0;
			}
			end=directory.indexOf("/",start);
			while(true){
				StringsubDirectory=newString(remote.substring(start,end).getBytes("GBK"),"iso-8859-1");
				if(!ftpClient.changeWorkingDirectory(subDirectory)){
					if(ftpClient.makeDirectory(subDirectory)){
						ftpClient.changeWorkingDirectory(subDirectory);
					}else{
						System.out.println("创建目录失败");
						returnUploadStatus.Create_Directory_Fail;
					}
				}
				
				start=end+1;
				end=directory.indexOf("/",start);
				
				//检查所有目录是否创建完毕
				if(end<=start){
					break;
				}
			}
		}
		returnstatus;
	}
	
	/**
	*上传文件到服务器,新上传和断点续传
	*@paramremoteFile远程文件名，在上传之前已经将服务器工作目录做了改变
	*@paramlocalFile本地文件File句柄，绝对路径
	*@paramprocessStep需要显示的处理进度步进值
	*@paramftpClientFTPClient引用
	*@return
	*@throwsIOException
	*/
	publicUploadStatusuploadFile(StringremoteFile,FilelocalFile,FTPClientftpClient,longremoteSize)throwsIOException{
		UploadStatusstatus;
		//显示进度的上传
		longstep=localFile.length()/100;
		longprocess=0;
		longlocalreadbytes=0L;
		RandomAccessFileraf=newRandomAccessFile(localFile,"r");
		OutputStreamout=ftpClient.appendFileStream(newString(remoteFile.getBytes("GBK"),"iso-8859-1"));
		//断点续传
		if(remoteSize>0){
			ftpClient.setRestartOffset(remoteSize);
			process=remoteSize/step;
			raf.seek(remoteSize);
			localreadbytes=remoteSize;
		}
		byte[]bytes=newbyte[1024];
		intc;
		while((c=raf.read(bytes))!=-1){
			out.write(bytes,0,c);
			localreadbytes+=c;
			if(localreadbytes/step!=process){
				process=localreadbytes/step;
				System.out.println("上传进度:"+process);
				//TODO汇报上传状态
			}
		}
		out.flush();
		raf.close();
		out.close();
		booleanresult=ftpClient.completePendingCommand();
		if(remoteSize>0){
			status=result?UploadStatus.Upload_From_Break_Success:UploadStatus.Upload_From_Break_Failed;
		}else{
			status=result?UploadStatus.Upload_New_File_Success:UploadStatus.Upload_New_File_Failed;
		}
		returnstatus;
	}
	
	publicstaticvoidmain(String[]args){
		ContinueFTPmyFtp=newContinueFTP();
		try{
			System.err.println(myFtp.connect("10.10.6.236",21,"5","jieyan"));
//			myFtp.ftpClient.makeDirectory(newString("歌曲".getBytes("GBK"),"iso-8859-1"));
//			myFtp.ftpClient.changeWorkingDirectory(newString("歌曲".getBytes("GBK"),"iso-8859-1"));
//			myFtp.ftpClient.makeDirectory(newString("爱你等于爱自己".getBytes("GBK"),"iso-8859-1"));
//			System.out.println(myFtp.upload("E:\yw.flv","/yw.flv",5));
//			System.out.println(myFtp.upload("E:\爱你等于爱自己.mp4","/爱你等于爱自己.mp4"));
			//System.out.println(myFtp.download("/爱你等于爱自己.mp4","E:\爱你等于爱自己.mp4"));
			myFtp.disconnect();
		}catch(IOExceptione){
			System.out.println("连接FTP出错："+e.getMessage());
		}
	}
}

‘贰’ java做web开发，如何设置一个按钮选择文件下载的本地路径，求大神指导

ie浏览器，工具，internet选项，安全，自定义级别

这个勾上之后，就可以通过file拿到他自己的路径了，getPath（）什么的，你自己试一下。

‘叁’ 用java下载指定路径下的文件夹，下载内容包含指定文件夹及其包含的文件夹子文件！！

这个做不了的, 在计算机,你用命令去复制粘贴都需要指定是否递归复制
也就是说,如果你想下载指定的文件夹,你需要做很多的处理,一个一个文件的下载,然后下载到相对路径中去,还有一种方案就是直接将文件夹打包再下载

‘肆’ Java Web项目实现上传文件以及下载文件功能的关于路径的问题

你这个项目用的maven来管理包和依赖的,但你不用太在意这个maven的目录结构啊.你做上传的时候应该把文件放到个单独的位置而不是放到src目录里面,因为这个src目录部署后是要拷到WEB-INF下面的classes目录的,如果确实需要这样做,那你就在写上传代码的时候把文件拷到target目录中