JAVA操作FTP（FTP工具类）

大家好，又见面了，我是你们的朋友全栈君。

Java 操作 FTP、FTP工具类、Java实现FTP代码示例

导入commons-net

<dependency>
    <groupId>commons-net</groupId>
    <artifactId>commons-net</artifactId>
    <version>3.6</version>
</dependency>

package com.my.ftp.test;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.StringTokenizer;
import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPClientConfig;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPReply;
public class Ftp { 

private String Control_Encoding = "UTF-8";
private FTPClient client = null;
private String host = "";
private int port = 21;
private String user = "";
private String password = "";
private String ftpPath = "/";
@SuppressWarnings("unused")
private Ftp() { 

}
public Ftp(String host, int port, String user, String pwd) { 

this.host = host;
this.port = port;
this.user = user;
this.password = pwd;
}
/** * 获取当前FTP所在目录位置 * * @return */
public String getHome() { 

return this.ftpPath;
}
/** * 连接FTP Server * * @throws IOException */
public static final String ANONYMOUS_USER = "anonymous";
public void connect() throws Exception { 

if (client == null) { 

client = new FTPClient();
}
// 已经连接
if (client.isConnected()) { 

return;
}
// 编码
client.setControlEncoding(Control_Encoding);
try { 

// 连接FTP Server
client.connect(this.host, this.port);
// 登陆
if (this.user == null || "".equals(this.user)) { 

// 使用匿名登陆
client.login(ANONYMOUS_USER, ANONYMOUS_USER);
} else { 

client.login(this.user, this.password);
}
// 设置文件格式
client.setFileType(FTPClient.BINARY_FILE_TYPE);
// 获取FTP Server 应答
int reply = client.getReplyCode();
if (!FTPReply.isPositiveCompletion(reply)) { 

client.disconnect();
throw new Exception("connection FTP fail!");
}
FTPClientConfig config = new FTPClientConfig(client.getSystemType().split(" ")[0]);
config.setServerLanguageCode("zh");
client.configure(config);
// 使用被动模式设为默认
client.enterLocalPassiveMode();
// 二进制文件支持
client.setFileType(FTP.BINARY_FILE_TYPE);
// 设置模式
client.setFileTransferMode(FTP.STREAM_TRANSFER_MODE);
} catch (IOException e) { 

throw new Exception("connection FTP fail! " + e);
}
}
/** * 断开FTP连接 * * @param ftpClient * @throws IOException */
public void close() { 

if (client != null && client.isConnected()) { 

try { 

client.logout();
client.disconnect();
} catch (IOException e) { 

e.printStackTrace();
}
}
}
/** * 获取文件列表 * * @return */
public List<FTPFile> list() { 

List<FTPFile> list = null;
try { 

FTPFile ff[] = client.listFiles(ftpPath);
if (ff != null && ff.length > 0) { 

list = new ArrayList<FTPFile>(ff.length);
Collections.addAll(list, ff);
} else { 

list = new ArrayList<FTPFile>(0);
}
} catch (IOException e) { 

e.printStackTrace();
}
return list;
}
/** * 切换目录 * * @param path * 需要切换的目录 * @param forcedIncrease * 如果目录不存在，是否增加 */
public void switchDirectory(String path, boolean forcedIncrease) { 

try { 

if (path != null && !"".equals(path)) { 

boolean ok = client.changeWorkingDirectory(path);
if (ok) { 

this.ftpPath = path;
} else if (forcedIncrease) { 

// ftpPath 不存在，手动创建目录
StringTokenizer token = new StringTokenizer(path, "\\//");
while (token.hasMoreTokens()) { 

String npath = token.nextToken();
client.makeDirectory(npath);
client.changeWorkingDirectory(npath);
if (ok) { 

this.ftpPath = path;
}
}
}
}
} catch (Exception e) { 

e.printStackTrace();
}
}
/** * 创建目录 * * @param path */
public void createDirectory(String path) { 

try { 

if (path != null && !"".equals(path)) { 

boolean ok = client.changeWorkingDirectory(path);
if (!ok) { 

// ftpPath 不存在，手动创建目录
StringTokenizer token = new StringTokenizer(path, "\\//");
while (token.hasMoreTokens()) { 

String npath = token.nextToken();
client.makeDirectory(npath);
client.changeWorkingDirectory(npath);
}
}
}
client.changeWorkingDirectory(this.ftpPath);
} catch (Exception e) { 

e.printStackTrace();
}
}
/** * 删除目录，如果目录中存在文件或者文件夹则删除失败 * * @param path * @return */
public boolean deleteDirectory(String path) { 

boolean flag = false;
try { 

flag = client.removeDirectory(path);
} catch (IOException e) { 

e.printStackTrace();
}
return flag;
}
/** * 删除文件 * * @param path * @return */
public boolean deleteFile(String path) { 

boolean flag = false;
try { 

flag = client.deleteFile(path);
} catch (IOException e) { 

e.printStackTrace();
}
return flag;
}
/** * 上传文件，上传文件只会传到当前所在目录 * * @param localFile * 本地文件 * @return */
public boolean upload(File localFile) { 

return this.upload(localFile, "");
}
/** * 上传文件，会覆盖FTP上原有文件 * * @param localFile * 本地文件 * @param reName * 重名 * @return */
public boolean upload(File localFile, String reName) { 

boolean flag = false;
String targetName = reName;
// 设置上传后文件名
if (reName == null || "".equals(reName)) { 

targetName = localFile.getName();
}
FileInputStream fis = null;
try { 

// 开始上传文件
fis = new FileInputStream(localFile);
client.setControlEncoding(Control_Encoding);
client.setFileType(FTPClient.BINARY_FILE_TYPE);
boolean ok = client.storeFile(targetName, fis);
if (ok) { 

flag = true;
}
} catch (IOException e) { 

e.printStackTrace();
}
return flag;
}
/** * 下载文件，如果存在会覆盖原文件 * * @param ftpFileName * 文件名称，FTP上的文件名称 * @param savePath * 保存目录，本地保存目录 * @return */
public boolean download(String ftpFileName, String savePath) { 

boolean flag = false;
File dir = new File(savePath);
if (!dir.exists()) { 

dir.mkdirs();
}
FileOutputStream fos = null;
try { 

String saveFile = dir.getAbsolutePath() + File.separator + ftpFileName;
fos = new FileOutputStream(new File(saveFile));
boolean ok = client.retrieveFile(ftpFileName, fos);
if (ok) { 

flag = true;
}
} catch (IOException e) { 

e.printStackTrace();
}
return flag;
}
public static void main(String args[]) { 

// 创建FTP对象
Ftp ftp = new Ftp("127.0.0.1", 21, "myftp", "myftp@2020");
try { 

// 连接FTP
ftp.connect();
// 移动工作空间、切换目录
System.out.println("当前位置：" + ftp.getHome());
ftp.switchDirectory("/test", true);
System.out.println("当前位置：" + ftp.getHome());
// 查询目录下的所有文件夹以及文件
List<FTPFile> list = ftp.list();
System.out.println("|-- " + ftp.getHome());
for (FTPFile f : list) { 

System.out.println(" |-- [" + (f.getType() == 0 ? "文件" : "文件夹") + "]" + f.getName());
}
// 上传文件
boolean r1 = ftp.upload(new File("C:\\Users\\joymt\\Documents\\ftp\\测试文件1.txt"), "测试文件2.txt");
System.out.println("上传文件：" + r1);
// 下载文件
boolean r2 = ftp.download("测试文件2.txt", "C:\\Users\\joymt\\Documents\\ftp");
System.out.println("下载文件：" + r2);
// 删除文件
boolean r3 = ftp.deleteFile("/test/测试文件2.txt");
System.out.println("删除文件：" + r3);
// 删除目录
boolean r4 = ftp.deleteDirectory("/test");
System.out.println("删除目录：" + r4);
} catch (Exception e) { 

e.printStackTrace();
}
ftp.close();
}
}