java基于Apache FTP点断续传的文件上传和下载

java基于Apache FTP点断续传的文件上传和下载

基于Apache FTP实现文件上传下载工具 ，上传文件时需要考虑以下问题（实例是续传功能）：

（1）、 FTP服务器是否存在改目录，cmyDw如果不存在目录则需要创建目录。

（2）、判断上传文件是否已经存在，如果存在是需要删除后再上传还是续传。

1、上传或下载状态的枚举类：

package com.scengine.wtms.utils.ftp;

public enum UploadStatus

{

File_Exits(0), Create_Directory_Success(1), Create_Directory_Fail(2), Upload_From_Break_Success(3), Upload_From_Break_Faild(4), Download_From_Break_Success(5), Download_From_Break_Faild(6), Upload_New_File_Success(7), Upload_New_File_Failed(8), Delete_Remote_Success(9), Delete_Remote_Faild(10),Remote_Bigger_Local(11),Remote_smaller_locall(12);

private int status;

public int getStatus()

{

return status;

}

public void setStatus(int status)

{

this.status = status;

}

UploadStatus(int status)

{

this.status = status;

}

}

2、工具类代码：

package com.scengine.wtms.utils.ftp;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.PrintWriter;

import org.apache.commons.net.PrintCommandListener;

import org.apache.commons.net.ftp.FTP;

import org.apache.commons.net.ftp.FTPClient;

import org.apache.commons.net.ftp.FTPFile;

import org.apache.commons.net.ftp.FTPReply;

public class ContinueFTP

{

private FTPClient ftpClient = new FTPClient();

/**

* 对象构造 设置将过程中使用到的命令输出到控制台

*/

public ContinueFTP()

{

this.ftpClient.addProtocolCommandListener(new PrintCommandListener(new PrintWriter(System.out)));

}

/**

*

* java编程中用于连接到FTP服务器

*

* @param hostname

* 主机名

*

* @param port

* 端口

*

* @param username

* 用户名

*

* @param password

* 密码

*

* @return 是否连接成功

*

* @throws IOException

*/

public boolean connect(String hostname, int port, String username, String password) throws IOException

{

ftpClient.connect(hostname, port);

if (FTPReply.isPositiveCompletion(ftpClient.getReplyCode()))

{

if (ftpClient.login(username, password))

{

return true;

}

}

disconnect();

return false;

}

/**

*

* 从FTP服务器上下载文件

*

* @param remote

* 远程文件路径

*

* @param local

* 本地文件路径

*

* @return 是否成功

*

* @throws IOException

*/

@SuppressWarnings("resource")

public boolean download(String remote, String local) throws IOException

{

ftpClient.enterLocalPassiveMode();

ftpClient.setFileType(FTP.BINARY_FILE_TYPE);

boolean result;

File f = new File(local);

FTPFile[] files = ftpClient.listFiles(remote);

if (files.length != 1)

{

System.out.println("远程文件不唯一");

return false;

}

long lRemoteSize = files[0].getSize();

if (f.exists())

{

OutputStream out = new FileOutputStream(f, true);

System.out.println("本地文件大小为:" + f.length());

if (f.length() >= lRemoteSize)

{

System.out.println("本地文件大小大于远程文件大小，下载中止");

return false;

}

ftpClient.setRestartOffset(f.length());

result = ftpClient.retrieveFile(remote, out);

out.close();

} else

{

OutputStream out = new FileOutputStream(f);

result = ftpClient.retrieveFile(remote, out);

out.close();

}

return result;

}

/**

*

* 上传文件到FTP服务器，支持断点续传

*

* @param local

* 本地文件名称，绝对路径

*

* @param remote

* 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

*

* @throws IOException

*/

@SuppressWarnings("resource")

public UploadStatus upload(String local, String remote) throws IOException

{

// 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);

UploadStatus result;

// 对远程目录的处理

String remoteFileName = remote;

if (remote.contains("/"))

{

remoteFileName = remote.substring(remote.lastIndexOf("/") + 1);

String directory = remote.substring(0, remote.lastIndexOf("/") + 1);

if (!directory.equalsIgnoreCase("/") && !ftpClient.changeWorkingDirectory(directory))

{

// 如果远程目录不存在，则递归创建远程服务器目录

int start = 0;

int end = 0;

if (directory.startsWith("/"))

{

start = 1;

} else

{

start = 0;

}

end = directory.indexOf("/", start);

while (true)

{

String subDirectory = remote.substring(start, end);

if (!ftpClient.changeWorkingDirectory(subDirectory))

{

if (ftpClient.makeDirectory(subDirectory))

{

ftpClient.changeWorkingDirectory(subDirectory);

} else

{

System.out.println("创建目录失败");

return UploadStatus.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;

}

}

}

}

// 检查远程是否存在文cmyDw件

FTPFile[] files = ftpClient.listFiles(remoteFileName);

if (files.length == 1)

{

long remoteSize = files[0].getSize();

File f = new File(local);

long localSize = f.length();

if (remoteSize == localSize)

{

return UploadStatus.File_Exits;

} else if (remoteSize > localSize)

{

return UploadStatus.Remote_Bigger_Local;

}

// 尝试移动文件内读取指针,实现断点续传

InputStream is = new FileInputStream(f);

if (is.skip(remoteSize) == remoteSize)

{

ftpClient.setRestartOffset(remoteSize);

if (ftpClient.storeFile(remote, is))

{

return UploadStatus.Upload_From_Break_Success;

}

}

// 如果断点续传没有成功，则删除服务器上文件，重新上传

if (!ftpClient.deleteFile(remoteFileName))

{

return UploadStatus.Delete_Remote_Faild;

}

is = new FileInputStream(f);

if (ftpClient.storeFile(remote, is))

{

result = UploadStatus.Upload_New_File_Success;

} else

{

result = UploadStatus.Upload_New_File_Failed;

}

is.close();

} else

{

InputStream is = new FileInputStream(local);

if (ftpClient.storeFile(remoteFileName, is))

{

result = UploadStatus.Upload_New_File_Success;

} else

{

result = UploadStatus.Upload_New_File_Failed;

}

is.close();

}

return result;

}

/**

*

* 断开与远程服务器的连接

*

* @throws IOException

*/

public void disconnect() throws IOException

{

if (ftpClient.isConnected())

{

ftpClient.disconnect();

}

}

public static void main(String[] args)

{

ContinueFTP myFtp = new ContinueFTP();

try

{

myFtp.connect("192.168.1.200", 21, "duser", "HTPDuserXP32");

System.out.println(myFtp.upload("C:\\Users\\Administrator\\Desktop\\swing.drawer.jar", "/jars/swing.drawer.jar"));

myFtp.disconnect();

} catch (IOException e)

{

System.out.println("连接FTP出错：" + e.getMessage());

}

}

}

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