这个就看代码，哈哈哈哈哈 需要用到的jar包是：
<dependency>
<groupId>commons-net</groupId>
<artifactId>commons-net</artifactId>
<version>3.3</version>
</dependency>
一：定义我们可能会返回的状态值。两个枚举类 一个异常类
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
}
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
}
//用于记录创建时候的异常
public class CreateException extends Exception{
private static Logger log = LoggerFactory.getLogger(CreateException.class);
private static final long serialVersionUID = 1L;
private Integer errCode;
private String errMessage;
public CreateException(Throwable cause, Integer errCode, String errMessage) {
super(cause);
this.errCode = errCode;
this.errMessage = errMessage;
}
public CreateException(Integer errCode, String errMessage) {
this.errCode = errCode;
this.errMessage = errMessage;
}
public CreateException(Integer errCode, UploadStatus uploadStatus) {
this.errCode = errCode;
this.errMessage = uploadStatus.toString();
}
public Integer getErrCode() {
return errCode;
}
public String getErrMessage() {
return errMessage;
}
}
二：创建连接ftp服务器的类
package com.utils.study.ftpCenter; import com.coocaa.core.generation.service.CreateBeanService;
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.FTPReply;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory; import java.io.IOException;
import java.io.PrintWriter; /**
* Created by yugaofeng on 2017/9/5.
*/
public class ContinueFTP {
private static Logger logger = LoggerFactory.getLogger(CreateBeanService.class); //定义一个客户端
private static FTPClient ftpClient ; //单例模式
public FTPClient getFtpClient(){
if(ftpClient == null){
ftpClient = new FTPClient();
}
return ftpClient;
} public ContinueFTP(){
getFtpClient().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 {
getFtpClient().connect(hostname, port);
if (FTPReply.isPositiveCompletion(getFtpClient().getReplyCode())) {
if (getFtpClient().login(username, password)) {
getFtpClient().enterLocalPassiveMode();
getFtpClient().setFileType(FTP.BINARY_FILE_TYPE);
return true;
}
}
disconnect();
return false;
} /**
* 断开与服务器的连接
* @throws IOException
*/
public void disconnect() throws IOException {
if (getFtpClient().isConnected()) {
getFtpClient().disconnect();
System.out.println("ftp is disconnect!");
}
}
}
这个时候 先测试一下 你能不能连接到服务器
public static void main(String[] args) throws IOException {
ContinueFTP ftp = new ContinueFTP();
System.out.println("<<<<<<<<<<<<<<<<<1"+ftp.getFtpClient().isConnected());
ftp.connect("172.20.139.217", 21, "ftp01", "ftp111");
System.out.println("<<<<<<<<<<<<<<<<<3"+ftp.getFtpClient().isConnected());
ftp.getFtpClient().disconnect();
}
表示连接成功
三：实现文件上传 和断点续传
由于设置了观察者 在观察当前上传的进度变化 ，本次代码中 没有添加观察者模式的代码，所以这个地方 可能需要先注释掉观察者
package com.utils.study.ftpCenter; import com.utils.study.CreateException;
import com.utils.study.enums.UploadStatus;
import com.utils.study.observerModel.FileObserverAble;
import com.utils.study.observerModel.FilePercentObserver;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile; import java.io.*; /**
* Created by yugaofeng on 2017/9/5.
*/
public class FileOperateByFtp { private FTPClient ftpClient; FileObserverAble fileObserverAble; public FileOperateByFtp(FTPClient ftpClient) {
//添加观察者对象
fileObserverAble = new FileObserverAble();
FilePercentObserver filePercentObserver = new FilePercentObserver(fileObserverAble);
this.ftpClient = ftpClient;
} /**
* 上传文件到FTP服务器，支持断点续传 并返回上传文件进度
* @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
*/
public UploadStatus upload(String local, String remote) throws Exception{
try {
if (!ftpClient.isConnected()) {
throw new CreateException(-1, "远程服务器相应目录创建失败");
}
UploadStatus result;
// 对远程目录的处理 并返回文件的名称
String remoteFileName = createDirectory(remote, ftpClient);
// 检查远程是否存在文件
FTPFile[] files = ftpClient.listFiles(remoteFileName);
File localFile = new File(local);
if(localFile.length() <=0){
throw new CreateException(-1,"本地文件不存在");
}
if (files.length == 1) {
//判断文件是否存在
long remoteSize = files[0].getSize();
long localSize = localFile.length();
if(remoteSize==localSize){
return UploadStatus.File_Exits;
}else if(remoteSize > localSize){
return UploadStatus.Remote_Bigger_Local;
}
result = this.writeByUnit(remoteFileName,localFile,ftpClient,remoteSize,localFile.length());
} else {
result = this.writeByUnit(remoteFileName,localFile,ftpClient,0,localFile.length());
}
return result;
}catch (CreateException e){
throw e;
}finally {
//上传完成之后 切回到根目录
ftpClient.changeWorkingDirectory("/");
}
} /**
* 判断目录
* @param remoteFilePath 远程服务器上面的 文件目录
* @param ftpClient ftp客户端
* @return
* @throws Exception
*/
private String createDirectory(String remoteFilePath,FTPClient ftpClient) throws Exception {
if(ftpClient == null){
throw new CreateException(-1,"FTP客户端为空,请先连接到客户端");
}
String fileName = remoteFilePath;
if(remoteFilePath.contains("/")){
fileName = remoteFilePath.substring(remoteFilePath.lastIndexOf("/") + 1);
String directory = remoteFilePath.substring(0, remoteFilePath.lastIndexOf("/") + 1);
if(directory.startsWith("/")){
directory = directory.substring(1);
}
while (true){
if(!directory.contains("/")){
break;
}
String subDirectory = directory.substring(0, directory.indexOf("/"));
directory = directory.substring(directory.indexOf("/")+1);
if (!ftpClient.changeWorkingDirectory(subDirectory)) {
if (ftpClient.makeDirectory(subDirectory)) {
ftpClient.changeWorkingDirectory(subDirectory);
} else {
throw new CreateException(-1,"创建目录失败");
}
}
}
}
return fileName;
} /**
* 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 ftpClient FTPClient引用 beginSize是指文件长传开始指针位置 endSize是结束的位置 为多线程上传下载提供接口 不过该方法还需要修改
* @return
* @throws IOException
*/ private UploadStatus writeByUnit(String remoteFile,File localFile,FTPClient ftpClient,long beginSize,long endSize) throws Exception {
long localSize = localFile.length();
if(endSize > localSize){
endSize = localSize;
}
if(beginSize < 0){
beginSize = 0;
}
//等待写入的文件大小
long writeSize = endSize - beginSize;
if(writeSize <= 0){
throw new CreateException(1,"文件指针参数出错");
}
//获取百分单位是 1-100
RandomAccessFile raf = new RandomAccessFile(localFile,"r");
OutputStream out = ftpClient.appendFileStream(new String(remoteFile.getBytes("GBK"),"iso-8859-1"));
//把文件指针移动到 开始位置
ftpClient.setRestartOffset(beginSize);
raf.seek(beginSize);
//定义最小移动单位是 1024字节 也就是1kb
byte[] bytes = new byte[1024];
int c;
double finishSize = 0;
double finishPercent = 0;
//存在一个bug 当分布移动的时候 可能会出现下载重复的问题 后期需要修改
while ((c = raf.read(bytes)) != -1) {
out.write(bytes, 0, c);
finishSize += c;
if(finishSize > writeSize){
finishPercent = 1;
//System.out.println(">>>>>完成进度:" + finishPercent);
fileObserverAble.setKeyValue(localFile.getName(),finishPercent,"upload");
break;
}
if ((finishSize / writeSize) - finishPercent > 0.01) {
finishPercent = finishSize / writeSize;
//System.out.println(">>>>>完成进度:" + finishPercent);
fileObserverAble.setKeyValue(localFile.getName(),finishPercent,"upload");
}
}
out.flush();
raf.close();
out.close();
boolean result =ftpClient.completePendingCommand();
return result?UploadStatus.Upload_From_Break_Success:UploadStatus.Upload_From_Break_Failed;
} /**
* 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
*/
public boolean download(String remote,String local) throws Exception{
FTPFile[] files = ftpClient.listFiles(remote);
if(files == null || files.length < 0){
throw new CreateException(-1,"远程文件不存在");
}
if(files.length != 1){
throw new CreateException(-1,"远程文件不唯一");
}
File localFile = new File(local);
if(localFile.exists()){
long localBeginSize = localFile.length();
if(localBeginSize == files[0].getSize()){
throw new CreateException(-1,"文件已经存在");
}else if(localBeginSize > files[0].getSize()){
throw new CreateException(-1,"下载文件出错");
}
return downloadByUnit(remote,local,localBeginSize,files[0].getSize());
}else {
return downloadByUnit(remote,local,0,files[0].getSize());
}
}
private Boolean downloadByUnit(String remote,String local,long beginSize,long endSize) throws Exception {
File localFile = new File(local);
long waitSize = endSize - beginSize;
//进行断点续传，并记录状态
FileOutputStream out = new FileOutputStream(localFile,true);
//把文件指针移动到 开始位置
ftpClient.setRestartOffset(beginSize);
InputStream in = ftpClient.retrieveFileStream(new String(remote.getBytes("GBK"),"iso-8859-1"));
byte[] bytes = new byte[1024];
int c;
double finishSize =0;
double finishPercent = 0;
while((c = in.read(bytes))!= -1){
out.write(bytes,0,c);
finishSize += c;
if(finishSize > waitSize){
//System.out.println(">>>>>完成进度:" + 1);
fileObserverAble.setKeyValue(localFile.getName(),1,"download"); }
if ((finishSize / waitSize) - finishPercent > 0.01) {
finishPercent = finishSize / waitSize;
//System.out.println(">>>>>完成进度:" + finishPercent);
fileObserverAble.setKeyValue(localFile.getName(),finishPercent,"download");
}
}
in.close();
out.close();
return ftpClient.completePendingCommand();
} }
测试上传 并在控制台打印出 上传百分百
public static void main(String[] args) {
ContinueFTP ftp = new ContinueFTP();
try {
ftp.connect("172.20.139.217", 21, "ftp01", "ftp111");
FileOperateByFtp fileOperateByFtp = new FileOperateByFtp(ftp.getFtpClient());
fileOperateByFtp.upload("F:\\upload7.temp","/upload2/f3/upload7.temp");
fileOperateByFtp.upload("F:\\upload6.temp","/upload2/f3/upload6.temp");
/* fileOperateByFtp.download("/upload2/f3/upload7.temp","F:\\upload6.temp");
fileOperateByFtp.download("//upload2/f3/upload6.temp","F:\\upload7.temp");*/
if(ftp.getFtpClient() != null){
ftp.getFtpClient().disconnect();
}
} catch (Exception e) {
if(e instanceof CreateException){
System.out.println(((CreateException) e).getErrMessage());
}
}
}
上传结果：
下载就不做演示
四：总结
ftp文件长传其实很简单，，实现断点续传也不能
ftp里面提供了一个 ftpClient.setRestartOffset(beginSize); 方法 实现了文件指针移动的开始位置 为后面的 分布式断点 多点上传 提供了 基础 .
另外关于文件显示进度比例，在这里实现也不能，但要是与前端进度条进行实时数据交互式不现实的。。。后来通过查阅资料发现有些还很有道理的。
比如我们服务器一般也会限制文件上传的大小，所以一般显示进度条是在前端做的，通过比较浏览器发送出去的数据量 和带上传的文件大小 进行比较来显示 进度条，但这种方法还没有测试成功，后面会进行验证。