Java读取传输FTP文件实现示例

<!-- FTP相关操作的依赖 -->
<dependency>
    <groupId>commons-net</groupId>
    <artifactId>commons-net</artifactId>
    <version>3.9.0</version>
</dependency>
<!-- IO工具类的依赖 -->
<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.11.0</version>
</dependency>
<!-- lombok依赖 -->
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.26</version>
    <scope>provided</scope>
</dependency>

ftp:
  config:
    host: ${env.ftp.config.host:10.1.1.1}
    port: ${env.ftp.config.port:12345}
    username: ${env.ftp.config.username:ftpUsername}
    passWord: ${env.ftp.config.password:ftpPwd}
    remote-dir-path: ${env.ftp.config.remote-dir-path:/}

@Data
@Component
@ConfigurationProperties("ftp.config")
public class FtpConfig {
    private String host;
    private int port;
    private String username;
    private String password;
    
    private String remoteDirPath;
}

public FTPClient getFtpClient(){
    try {
        FTPClient ftpClient = new FTPClient();
        ftpClient.connect(ftpConfig.getHost() ,ftpConfig.getPort());
        // 10分钟连接时间
        ftpClient.setConnectTimeout(600000);
        ftpClient.setDefaultTimeout(600000);
        ftpClient.login(ftpConfig.getUsername() ,ftpConfig.getPassword());
        // login后设置传输的模式
        ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
        // login后设置被动模式
        ftpClient.enterLocalPassiveMode();
        // login后设置编码
        String LOCAL_CHARSET = "GBK";
        // 开启服务器对UTF-8的支持，如果服务器支持就用UTF-8编码，否则就使用本地编码（GBK）.
        if (FTPReply.isPositiveCompletion(ftpClient.sendCommand("OPTS UTF8", "ON"))) {
            LOCAL_CHARSET = "UTF-8";
        }
        ftpClient.setControlEncoding(LOCAL_CHARSET);
        if (!FTPReply.isPositiveCompletion(ftpClient.getReplyCode())) {
            log.error("未连接到FTP，用户名或密码错误！");
            ftpClient.disconnect();
        } else {
            log.info("FTP连接成功！");
        }
        // 切换从某个根目录下开始扫描
        ftpClient.changeWorkingDirectory(ftpConfig.getRemoteDirPath());
        return ftpClient;
    }catch (IOException e) {
        log.error("ftp建立连接异常->{}", e);
    }
    return null;
}

public void getFtpFirstDirectoryFiles(FTPClient ftpClient) throws IOException {
    log.info("ftpclient当前工作目录->{}", ftpClient.printWorkingDirectory());
    if (ftpClient != null) {
        FTPFile[] files = ftpClient.listFiles();
        for (FTPFile file : files) {
            String fileName = file.getName();
            if (file.isDirectory()){
                // 每次从根目录下查找第一级目录
                String firstDirectory = ftpConfig.getRemoteDirPath() + "/" + fileName;
                ftpClient.changeWorkingDirectory(firstDirectory);
                log.info("当前目录->{}, 开始扫描录音文件", firstDirectory);
                // 切换目录后直接遍历第一级的文件，不递归第二级目录
                dealFile(ftpClient);
                log.info("{}->目录扫描结束", firstDirectory);
            }
        }
    }
}

public void dealFile(FTPClient ftpClient) throws IOException {
    FTPFile[] files = ftpClient.listFiles();
        for (FTPFile file : files) {
            String fileName = file.getName();
            if (file.isDirectory()) {
                log.info("{}->为目录，跳过", fileName);
                continue;
            }
            String rootWorkingDirectory = ftpClient.printWorkingDirectory();
            log.info("获取到文件->{}, 开始获取ftp文件流, ftpclient工作目录->{}", fileName, ftpClient.printWorkingDirectory());
            // 开始获取ftp文件流
            InputStream inputStream = ftpClient.retrieveFileStream(new String(fileName.getBytes("UTF-8"), FTP.DEFAULT_CONTROL_ENCODING));
            if (inputStream == null){
                log.error("文件不存在->{}", fileName);
                return;
            }
            byte[] data = IOUtils.toByteArray(inputStream);
            inputStream.close();
            // 关键代码，如果不执行该代码，后续的ftpClient操作将会不生效
            ftpClient.completePendinGCommand();
            // 省略...获取到了inputStream 文件流进行后续处理
           }
}

public void disConnection(FTPClient ftpClient) {
    try{
        if(ftpClient.isConnected()){
            ftpClient.disconnect();
        }
    }catch(IOException e) {
        log.error("ftpClient.disconnect失败->{}", e);
    }
}