java实现多线程断点续传,上传下载

Posted 2020-07-11 EliteQing

采用apache 的 commons-net-ftp-ftpclient

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.RandomAccessFile;

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;
import org.junit.Test;
/** *//**
* 支持断点续传的FTP实用类
* @version 0.1 实现基本断点上传下载
* @version 0.2 实现上传下载进度汇报
* @version 0.3 实现中文目录创建及中文文件创建，添加对于中文的支持
*/
public class ContinuedFTP{

//枚举类UploadStatus代码

public enum UploadStatus {
Create_Directory_Fail, //远程服务器相应目录创建失败
Create_Directory_Success, //远程服务器闯将目录成功
Upload_New_File_Success, //上传新文件成功
Upload_New_File_Failed, //上传新文件失败
File_Exits, //文件已经存在
Remote_Bigger_Local, //远程文件大于本地文件
Upload_From_Break_Success, //断点续传成功
Upload_From_Break_Failed, //断点续传失败
Delete_Remote_Faild; //删除远程文件失败
}

//枚举类DownloadStatus代码
public enum DownloadStatus {
Remote_File_Noexist, //远程文件不存在
Local_Bigger_Remote, //本地文件大于远程文件
Download_From_Break_Success, //断点下载文件成功
Download_From_Break_Failed, //断点下载文件失败
Download_New_Success, //全新下载文件成功
Download_New_Failed; //全新下载文件失败
}

public FTPClient ftpClient = new FTPClient();
private String ftpURL,username,pwd,ftpport,file1,file2;
public ContinueFTP2(String _ftpURL,String _username,String _pwd,String _ftpport,String _file1,String _file2 ){
//设置将过程中使用到的命令输出到控制台
ftpURL = _ftpURL;
username = _username;
pwd = _pwd;
ftpport = _ftpport;
file1 = _file1;
file2 = _file2;
this.ftpClient.addProtocolCommandListener(new PrintCommandListener(new PrintWriter(System.out)));
}

/** *//**
* 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);
ftpClient.setControlEncoding("GBK");
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,支持断点续传，上传百分比汇报
* @param remote 远程文件路径
* @param local 本地文件路径
* @return 上传的状态
* @throws IOException
*/
public DownloadStatus download(String remote,String local) throws IOException{
//设置被动模式
ftpClient.enterLocalPassiveMode();
//设置以二进制方式传输
ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
DownloadStatus result;

//检查远程文件是否存在
FTPFile[] files = ftpClient.listFiles(new String(remote.getBytes("GBK"),"iso-8859-1"));
if(files.length != 1){
System.out.println("远程文件不存在");
return DownloadStatus.Remote_File_Noexist;
}

long lRemoteSize = files[0].getSize();
File f = new File(local);
//本地存在文件，进行断点下载
if(f.exists()){
long localSize = 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");
return DownloadStatus.Local_Bigger_Remote;
}

//进行断点续传，并记录状态
FileOutputStream out = new FileOutputStream(f,true);
ftpClient.setRestartOffset(localSize);
InputStream in = ftpClient.retrieveFileStream(new String(remote.getBytes("GBK"),"iso-8859-1"));
byte[] bytes = new byte[1024];
long step = lRemoteSize /100;
long process=localSize /step;
int c;
while((c = in.read(bytes))!= -1){
out.write(bytes,0,c);
localSize+=c;
long nowProcess = 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();
boolean isDo = ftpClient.completePendingCommand();
if(isDo){
result = DownloadStatus.Download_From_Break_Success;
}else {
result = DownloadStatus.Download_From_Break_Failed;
}
}else {
OutputStream out = new FileOutputStream(f);
InputStream in= ftpClient.retrieveFileStream(new String(remote.getBytes("GBK"),"iso-8859-1"));
byte[] bytes = new byte[1024];
long step = lRemoteSize /100;
long process=0;
long localSize = 0L;
int c;
while((c = in.read(bytes))!= -1){
out.write(bytes, 0, c);
localSize+=c;
long nowProcess = 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();
boolean upNewStatus = ftpClient.completePendingCommand();
if(upNewStatus){
result = DownloadStatus.Download_New_Success;
}else {
result = DownloadStatus.Download_New_Failed;
}
}
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或是 http://www.guihua.org /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
*/
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);
ftpClient.setControlEncoding("GBK");
UploadStatus result;
//对远程目录的处理
String remoteFileName = 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){
return UploadStatus.Create_Directory_Fail;
}
}

//检查远程是否存在文件
FTPFile[] files = ftpClient.listFiles(new String(remoteFileName.getBytes("GBK"),"iso-8859-1"));
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
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)){
return UploadStatus.Delete_Remote_Faild;
}
result = uploadFile(remoteFileName, f, ftpClient, 0);
}
}else {
result = uploadFile(remoteFileName, new File(local), ftpClient, 0);
}
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();
}
}

/** *//**
* 递归创建远程服务器目录
* @param remote 远程服务器文件绝对路径
* @param ftpClient FTPClient 对象
* @return 目录创建是否成功
* @throws IOException
*/
public UploadStatus CreateDirecroty(String remote,FTPClient ftpClient) throws IOException{
UploadStatus status = UploadStatus.Create_Directory_Success;
String directory = remote.substring(0,remote.lastIndexOf("/")+1);
if(!directory.equalsIgnoreCase("/")&&!ftpClient.changeWorkingDirectory(new String(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
int start=0;
int end = 0;
if(directory.startsWith("/")){
start = 1;
}else{
start = 0;
}
end = directory.indexOf("/",start);
while(true){
String subDirectory = new String(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");
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;
}
}
}
return status;
}

/** *//**
* 上传文件到服务器,新上传和断点续传
* @param remoteFile 远程文件名，在上传之前已经将服务器工作目录做了改变
* @param localFile 本地文件 File句柄，绝对路径
* @param processStep 需要显示的处理进度步进值
* @param ftpClient FTPClient 引用
* @return
* @throws IOException
*/
public UploadStatus uploadFile(String remoteFile,File localFile,FTPClient ftpClient,long remoteSize) throws IOException{
UploadStatus status;
//显示进度的上传
long step = localFile.length() / 100;
long process = 0;
long localreadbytes = 0L;
RandomAccessFile raf = new RandomAccessFile(localFile,"r");
OutputStream out = ftpClient.appendFileStream(new String(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 = new byte[1024];
int c;
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();
boolean result =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;
}
return status;
}
}

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