- 技术人生
- JAVA实现FTP断点上传
import java.io.File;
002 import java.io.FileInputStream;
003 import java.io.FileOutputStream;
004 import java.io.IOException;
005 import java.io.InputStream;
006 import java.io.OutputStream;
007 import java.io.PrintWriter;
008 import org.apache.commons.net.PrintCommandListener;
009 import org.apache.commons.net.ftp.FTP;
010 import org.apache.commons.net.ftp.FTPClient;
011 import org.apache.commons.net.ftp.FTPFile;
012 import org.apache.commons.net.ftp.FTPReply;
013
014 public class ContinueFTP {
015 private FTPClient ftpClient = new FTPClient();
016
017 public ContinueFTP(){
018 //设置将过程中使用到的命令输出到控制台
019 this.ftpClient.addProtocolCommandListener(new PrintCommandListener(new PrintWriter(System.out)));
020 }
021
022 /**
023 * java编程中用于连接到FTP服务器
024 * @param hostname 主机名
025 * @param port 端口
026 * @param username 用户名
027 * @param password 密码
028 * @return 是否连接成功
029 * @throws IOException
030 */
031 public boolean connect(String hostname,int port,String username,String password) throws IOException{
032 ftpClient.connect(hostname, port);
033 if(FTPReply.isPositiveCompletion(ftpClient.getReplyCode())){
034 if(ftpClient.login(username, password)){
035 return true;
036 }
037 }
038 disconnect();
039 return false;
040 }
041
042 /**
043 * 从FTP服务器上下载文件
044 * @param remote 远程文件路径
045 * @param local 本地文件路径
046 * @return 是否成功
047 * @throws IOException
048 */
049 public boolean download(String remote,String local) throws IOException{
050 ftpClient.enterLocalPassiveMode();
051 ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
052 boolean result;
053 File f = new File(local);
054 FTPFile[] files = ftpClient.listFiles(remote);
055 if(files.length != 1){
056 System.out.println("远程文件不唯一");
057 return false;
058 }
059 long lRemoteSize = files[0].getSize();
060 if(f.exists()){
061 OutputStream out = new FileOutputStream(f,true);
062 System.out.println("本地文件大小为:"+f.length());
063 if(f.length() >= lRemoteSize){
064 System.out.println("本地文件大小大于远程文件大小，下载中止");
065 return false;
066 }
067 ftpClient.setRestartOffset(f.length());
068 result = ftpClient.retrieveFile(remote, out);
069 out.close();
070 }else {
071 OutputStream out = new FileOutputStream(f);
072 result = ftpClient.retrieveFile(remote, out);
073 out.close();
074 }
075 return result;
076 }
077
078 /**
079 * 上传文件到FTP服务器，支持断点续传
080 * @param local 本地文件名称，绝对路径
081 * @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
082 * @return 上传结果
083 * @throws IOException
084 */
085 public UploadStatus upload(String local,String remote) throws IOException{
086 //设置PassiveMode传输
087 ftpClient.enterLocalPassiveMode();
088 //设置以二进制流的方式传输
089 ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
090 UploadStatus result;
091 //对远程目录的处理
092 String remoteFileName = remote;
093 if(remote.contains("/")){
094 remoteFileName = remote.substring(remote.lastIndexOf("/")+1);
095 String directory = remote.substring(0,remote.lastIndexOf("/")+1);
096 if(!directory.equalsIgnoreCase("/")&&!ftpClient.changeWorkingDirectory(directory)){
097 //如果远程目录不存在，则递归创建远程服务器目录
098 int start=0;
099 int end = 0;
100 if(directory.startsWith("/")){
101 start = 1;
102 }else{
103 start = 0;
104 }
105 end = directory.indexOf("/",start);
106 while(true){
107 String subDirectory = remote.substring(start,end);
108 if(!ftpClient.changeWorkingDirectory(subDirectory)){
109 if(ftpClient.makeDirectory(subDirectory)){
110 ftpClient.changeWorkingDirectory(subDirectory);
111 }else {
112 System.out.println("创建目录失败");
113 return UploadStatus.Create_Directory_Fail;
114 }
115 }
116
117 start = end + 1;
118 end = directory.indexOf("/",start);
119
120 //检查所有目录是否创建完毕
121 if(end <= start){
122 break;
123 }
124 }
125 }
126 }
127
128 //检查远程是否存在文件
129 FTPFile[] files = ftpClient.listFiles(remoteFileName);
130 if(files.length == 1){
131 long remoteSize = files[0].getSize();
132 File f = new File(local);
133 long localSize = f.length();
134 if(remoteSize==localSize){
135 return UploadStatus.File_Exits;
136 }else if(remoteSize > localSize){
137 return UploadStatus.Remote_Bigger_Local;
138 }
139
140 //尝试移动文件内读取指针,实现断点续传
141 InputStream is = new FileInputStream(f);
142 if(is.skip(remoteSize)==remoteSize){
143 ftpClient.setRestartOffset(remoteSize);
144 if(ftpClient.storeFile(remote, is)){
145 return UploadStatus.Upload_From_Break_Success;
146 }
147 }
148
149 //如果断点续传没有成功，则删除服务器上文件，重新上传
150 if(!ftpClient.deleteFile(remoteFileName)){
151 return UploadStatus.Delete_Remote_Faild;
152 }
153 is = new FileInputStream(f);
154 if(ftpClient.storeFile(remote, is)){
155 result = UploadStatus.Upload_New_File_Success;
156 }else{
157 result = UploadStatus.Upload_New_File_Failed;
158 }
159 is.close();
160 }else {
161 InputStream is = new FileInputStream(local);
162 if(ftpClient.storeFile(remoteFileName, is)){
163 result = UploadStatus.Upload_New_File_Success;
164 }else{
165 result = UploadStatus.Upload_New_File_Failed;
166 }
167 is.close();
168 }
169 return result;
170 }
171 /**
172 * 断开与远程服务器的连接
173 * @throws IOException
174 */
175 public void disconnect() throws IOException{
176 if(ftpClient.isConnected()){
177 ftpClient.disconnect();
178 }
179 }
180
181 public static void main(String[] args) {
182 ContinueFTP myFtp = new ContinueFTP();
183 try {
184 myFtp.connect("192.168.21.171", 21, "test", "test");
185 System.out.println(myFtp.upload("E://VP6.flv", "/MIS/video/VP6.flv"));
186 myFtp.disconnect();
187 } catch (IOException e) {
188 System.out.println("连接FTP出错："+e.getMessage());
189 }
190 }
191 }
