最近專案中需要實現將檔案先存放到ftp上，需要的時候再從ftp上下載，做的過程中碰到了問題，發現中文檔名的無法上傳到ftp上，ftp上的中文檔名的檔案下載不下來，幾番折騰，終於搞定了，記錄一下備忘。

首先給工程新增maven依賴，pom.xml檔案中新增：

<dependency>
    <groupId>commons-net</groupId>
    <artifactId>commons-net</artifactId>
    <version>1.4.1</version>
</dependency>
 

以下是Ftp工具類:

package com.test.util;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.SocketException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPReply;

public class FtpUtil {
    private final static Log logger = LogFactory.getLog(FtpUtil.class);  
	  
    /** 
     * 獲取FTPClient物件 
     * @param ftpHost       FTP主機伺服器 
     * @param ftpPassword   FTP 登入密碼 
     * @param ftpUserName   FTP登入使用者名稱 
     * @param ftpPort       FTP埠 預設為21 
     * @return 
     */  
    public static FTPClient getFTPClient(String ftpHost, String ftpUserName, String ftpPassword, int ftpPort) {  
        FTPClient ftpClient = new FTPClient();  
        try {  
            ftpClient = new FTPClient();  
            ftpClient.connect(ftpHost, ftpPort);              // 連線FTP伺服器  
            ftpClient.login(ftpUserName, ftpPassword);        // 登陸FTP伺服器 
            ftpClient.setControlEncoding("UTF-8"); 
 
            // 中文支援  
            ftpClient.setFileType(FTPClient.BINARY_FILE_TYPE);  
            ftpClient.enterLocalPassiveMode();  
            if (!FTPReply.isPositiveCompletion(ftpClient.getReplyCode())) {  
                logger.info("未連線到FTP，使用者名稱或密碼錯誤。");  
                ftpClient.disconnect();  
            } else {  
                logger.info("FTP連線成功。");  
            }  
        } catch (SocketException e) {  
            e.printStackTrace();  
            logger.info("FTP的IP地址可能錯誤，請正確配置。");  
        } catch (IOException e) {  
            e.printStackTrace();  
            logger.info("FTP的埠錯誤,請正確配置。");  
        }  
        return ftpClient;  
    }  
  
    /* 
     * 從FTP伺服器下載檔案 
     * @param ftpHost             FTP IP地址 
     * @param ftpUserName         FTP 使用者名稱 
     * @param ftpPassword         FTP使用者名稱密碼 
     * @param ftpPort             FTP埠 
     * @param ftpPath             FTP伺服器中檔案所在路徑 格式： ftptest/aa 
     * @param localPath           下載到本地的位置 格式：H:/download 
     * @param fileName            FTP伺服器上要下載的檔名稱
     * @param targetFileName      FTP伺服器上要下載的檔名稱 
     */  
    public static void downloadFtpFile(String ftpHost, String ftpUserName, String ftpPassword, int ftpPort, String ftpPath, String localPath, String fileName, String targetFileName) {  
  
        FTPClient ftpClient = null;  
        try {  
            ftpClient = getFTPClient(ftpHost, ftpUserName, ftpPassword, ftpPort);  
            ftpClient.changeWorkingDirectory(ftpPath);
            
            String f_ame = new String(fileName.getBytes("GBK"), FTP.DEFAULT_CONTROL_ENCODING);	//編碼檔案格式,解決中文檔名
 

            
            File localFile = new File(localPath + File.separatorChar + targetFileName);  
            OutputStream os = new FileOutputStream(localFile);  
            ftpClient.retrieveFile(f_ame, os);  
            os.close();  
            ftpClient.logout();  
  
        } catch (FileNotFoundException e) {  
            logger.error("沒有找到" + ftpPath + "檔案");  
            e.printStackTrace();  
        } catch (SocketException e) {  
            logger.error("連線FTP失敗.");  
            e.printStackTrace();  
        } catch (IOException e) {  
            e.printStackTrace();  
            logger.error("檔案讀取錯誤。");  
            e.printStackTrace();  
        }  
    }
    
    /**  
     * Description:             向FTP伺服器上傳檔案  
     * @param host              FTP伺服器hostname  
     * @param port              FTP伺服器埠  
     * @param username          FTP登入賬號  
     * @param password          FTP登入密碼  
     * @param basePath          FTP伺服器基礎目錄 
     * @param filePath          FTP伺服器檔案存放路徑。例如分日期存放：/2015/01/01。檔案的路徑為basePath+filePath 
     * @param filename          上傳到FTP伺服器上的檔名  
     * @param input             輸入流  
     * @return                  成功返回true，否則返回false  
     */    
    public static boolean uploadFile(String ftpHost, String ftpUserName, String ftpPassword, int ftpPort, String ftpPath, String filename, InputStream input) {  
        boolean result = false;  
        FTPClient ftpClient = new FTPClient();  
        try {  
            int reply;  
            ftpClient = getFTPClient(ftpHost, ftpUserName, ftpPassword, ftpPort);  
            ftpClient.changeWorkingDirectory(ftpPath);
            
            reply = ftpClient.getReplyCode();
            if (!FTPReply.isPositiveCompletion(reply)) {
                ftpClient.disconnect();
                return result;
            }
            
            filename = new String(filename.getBytes("GBK"), FTP.DEFAULT_CONTROL_ENCODING);    //編碼檔名，支援中文檔名
            //上傳檔案  
            if (!ftpClient.storeFile(filename, input)) {  
                return result;  
            }  
            input.close();  
            ftpClient.logout();  
            result = true;  
        } catch (IOException e) {  
            e.printStackTrace();  
        } finally {  
            if (ftpClient.isConnected()) {  
                try {  
                	ftpClient.disconnect();  
                } catch (IOException ioe) {  
                }  
            }  
        }  
        return result;  
    }
    
    public static void main(String[] args) {
        String ftpHost = "192.168.20.40";
        String ftpUserName = "test";
        String ftpPassword = "12345";
        int ftpPort = 21;
        String ftpPath = "test/";
        String fileName = "test_通知_4724.docx";

        //上傳一個檔案
        try{
            String tmpPath = System.getProperty("java.io.tmpdir");
            FileInputStream in=new FileInputStream(new File("D:\\" + fileName));
            FtpUtil.uploadFile(ftpHost, ftpUserName,  ftpPassword, ftpPort, ftpPath, fileName, in);
            
            System.out.println(tmpPath);
            FtpUtil.downloadFtpFile(ftpHost, ftpUserName, ftpPassword, ftpPort, ftpPath, "E:\\", "test_通知_4724.docx", "測試下載檔案.docx"); 
        } catch (Exception e){
            e.printStackTrace();
            System.out.println(e);
        }
    }
}