java中ftp斷點上傳功能的實作

主要使用apache中的net包來實作。網址http://commons.apache.org/net/。具體包的下載下傳和API文檔請看官網。

    斷點上傳就是在上傳的過程中設定傳輸的起始位置。并設定二進制傳輸。

Java代碼

1. package apache.net.test;   
2. import java.io.File;   
3. import java.io.FileInputStream;   
4. import java.io.FileOutputStream;   
5. import java.io.IOException;   
6. import java.io.InputStream;   
7. import java.io.OutputStream;   
8. import java.io.PrintWriter;   
9. import org.apache.commons.net.PrintCommandListener;   
10. import org.apache.commons.net.ftp.FTP;   
11. import org.apache.commons.net.ftp.FTPClient;   
12. import org.apache.commons.net.ftp.FTPFile;   
13. import org.apache.commons.net.ftp.FTPReply;   
14. public class ContinueFTP {   
15.     private FTPClient ftpClient = new FTPClient();   
16.     public ContinueFTP(){   
17.         //設定将過程中使用到的指令輸出到控制台   
18.         this.ftpClient.addProtocolCommandListener(new PrintCommandListener(new PrintWriter(System.out)));   
19.     }   
20.     public boolean connect(String hostname,int port,String username,String password) throws IOException{   
21.         ftpClient.connect(hostname, port);   
22.         if(FTPReply.isPositiveCompletion(ftpClient.getReplyCode())){   
23.             if(ftpClient.login(username, password)){   
24.                 return true;   
25.             }   
26.         }   
27.         disconnect();   
28.         return false;   
29.     }   
30.     public boolean download(String remote,String local) throws IOException{   
31.         ftpClient.enterLocalPassiveMode();   
32.         ftpClient.setFileType(FTP.BINARY_FILE_TYPE);   
33.         boolean result;   
34.         File f = new File(local);   
35.         FTPFile[] files = ftpClient.listFiles(remote);   
36.         if(files.length != 1){   
37.             System.out.println("遠端檔案不唯一");   
38.             return false;   
39.         }   
40.         long lRemoteSize = files[0].getSize();   
41.         if(f.exists()){   
42.             OutputStream out = new FileOutputStream(f,true);   
43.             System.out.println("本地檔案大小為:"+f.length());   
44.             if(f.length() >= lRemoteSize){   
45.                 System.out.println("本地檔案大小大于遠端檔案大小，下載下傳中止");   
46.                 return false;   
47.             }   
48.             ftpClient.setRestartOffset(f.length());   
49.             result = ftpClient.retrieveFile(remote, out);   
50.             out.close();   
51.         }else {   
52.             OutputStream out = new FileOutputStream(f);   
53.             result = ftpClient.retrieveFile(remote, out);   
54.             out.close();   
55.         }   
56.         return result;   
57.     }   
58.     public UploadStatus upload(String local,String remote) throws IOException{   
59.         //設定PassiveMode傳輸   
60.         ftpClient.enterLocalPassiveMode();   
61.         //設定以二進制流的方式傳輸   
62.         ftpClient.setFileType(FTP.BINARY_FILE_TYPE);   
63.         UploadStatus result;   
64.         //對遠端目錄的處理   
65.         String remoteFileName = remote;   
66.         if(remote.contains("/")){   
67.             remoteFileName = remote.substring(remote.lastIndexOf("/")+1);   
68.             String directory = remote.substring(0,remote.lastIndexOf("/")+1);   
69.             if(!directory.equalsIgnoreCase("/")&&!ftpClient.changeWorkingDirectory(directory)){   
70.                 //如果遠端目錄不存在，則遞歸建立遠端伺服器目錄   
71.                 int start=0;   
72.                 int end = 0;   
73.                 if(directory.startsWith("/")){   
74.                     start = 1;   
75.                 }else{   
76.                     start = 0;   
77.                 }   
78.                 end = directory.indexOf("/",start);   
79.                 while(true){   
80.                     String subDirectory = remote.substring(start,end);   
81.                     if(!ftpClient.changeWorkingDirectory(subDirectory)){   
82.                         if(ftpClient.makeDirectory(subDirectory)){   
83.                             ftpClient.changeWorkingDirectory(subDirectory);   
84.                         }else {   
85.                             System.out.println("建立目錄失敗");   
86.                             return UploadStatus.Create_Directory_Fail;   
87.                         }   
88.                     }   
89.                     start = end + 1;   
90.                     end = directory.indexOf("/",start);   
91.                     //檢查所有目錄是否建立完畢   
92.                     if(end <= start){   
93.                         break;   
94.                     }   
95.                 }   
96.             }   
97.         }   
98.         //檢查遠端是否存在檔案   
99.         FTPFile[] files = ftpClient.listFiles(remoteFileName);   
100.         if(files.length == 1){   
101.             long remoteSize = files[0].getSize();   
102.             File f = new File(local);   
103.             long localSize = f.length();   
104.             if(remoteSize==localSize){   
105.                 return UploadStatus.File_Exits;   
106.             }else if(remoteSize > localSize){   
107.                 return UploadStatus.Remote_Bigger_Local;   
108.             }   
109.             //嘗試移動檔案内讀取指針,實作斷點續傳   
110.             InputStream is = new FileInputStream(f);   
111.             if(is.skip(remoteSize)==remoteSize){   
112.                 ftpClient.setRestartOffset(remoteSize);   
113.                 if(ftpClient.storeFile(remote, is)){   
114.                     return UploadStatus.Upload_From_Break_Success;   
115.                 }   
116.             }   
117.             //如果斷點續傳沒有成功，則删除伺服器上檔案，重新上傳   
118.             if(!ftpClient.deleteFile(remoteFileName)){   
119.                 return UploadStatus.Delete_Remote_Faild;   
120.             }   
121.             is = new FileInputStream(f);   
122.             if(ftpClient.storeFile(remote, is)){       
123.                 result = UploadStatus.Upload_New_File_Success;   
124.             }else{   
125.                 result = UploadStatus.Upload_New_File_Failed;   
126.             }   
127.             is.close();   
128.         }else {   
129.             InputStream is = new FileInputStream(local);   
130.             if(ftpClient.storeFile(remoteFileName, is)){   
131.                 result = UploadStatus.Upload_New_File_Success;   
132.             }else{   
133.                 result = UploadStatus.Upload_New_File_Failed;   
134.             }   
135.             is.close();   
136.         }   
137.         return result;   
138.     }   
139.     public void disconnect() throws IOException{   
140.         if(ftpClient.isConnected()){   
141.             ftpClient.disconnect();   
142.         }   
143.     }   
144.     public static void main(String[] args) {   
145.         ContinueFTP myFtp = new ContinueFTP();   
146.         try {   
147.             myFtp.connect("192.168.21.171", 21, "test", "test");   
148.             System.out.println(myFtp.upload("E:\\VP6.flv", "/MIS/video/VP6.flv"));   
149.             myFtp.disconnect();   
150.         } catch (IOException e) {   
151.             System.out.println("連接配接FTP出錯："+e.getMessage());   
152.         }   
153.     }   
154. }