java從ftp服務器上拉取文件，並做相應的處理

項目採用的是springboot，依賴管理工具用的是gradle，配置文件是yml文件
1.導入相關ftp需要的jar包
dependencies {
compile group: ‘commons-net’, name: ‘commons-net’, version: “3.6”｝
2.創建ftp相關的配置類
@ConfigurationProperties(prefix = “ftp”)
@Data
public class FTPConfigProperties {
private String address;
private int port;
private String username;
private String password;
private String localFilePath;
}
3.創建ftp相關的utils
@Slf4j
public class FTPFileManager {

private String address;
private int port;
private String username;
private String password;
private String localFilePath;

//different company's files save different foladers
public FTPFileManager(String companyName, FTPConfigProperties ftpConfigProperties) {
    this.ftpRoot = "/" + companyName + "/";
    address = ftpConfigProperties.getAddress();
    port = ftpConfigProperties.getPort();
    username = ftpConfigProperties.getUsername();
    password = ftpConfigProperties.getPassword();
    localFilePath = ftpConfigProperties.getLocalFilePath();
}

// TODO pass as constructor parameter
private String ftpRoot;

private FTPClient readFTP;

private List<File> files = new ArrayList<>();
private List<File> doneFiles = new ArrayList<>();
private List<File> errorFiles = new ArrayList<>();

public List<File> fetch() throws IOException {
    this.readFTP = this.connect();

    readFTP.changeWorkingDirectory(ftpRoot);
    FTPFile[] files = readFTP.listFiles();
    for (FTPFile file : files) {
        if (file.getName().contains(".csv")) {
            File localFile = new File(localFilePath + file.getName());
            FileOutputStream os = new FileOutputStream(localFile);
            try {
                readFTP.retrieveFile(file.getName(), os);
                this.files.add(localFile);
            } catch (IOException e) {
                log.error("error", e);
            } finally {
                os.close();
            }
        }
    }

    return this.files;
}

public void fileDone(File file) {
    doneFiles.add(file);
}

public void fileError(File file) {
    errorFiles.add(file);
}

public void clean() throws IOException {
    try {
        for(File file :this.doneFiles) {
        readFTP.changeWorkingDirectory(ftpRoot + Folder.DONE);
        boolean moved = readFTP.rename(ftpRoot + file.getName(), file.getName());
        log.info("{} moved to done:{}", file.getName(), moved);
    }
    for (File file : this.errorFiles) {
        readFTP.changeWorkingDirectory(ftpRoot + Folder.ERROR);
        boolean moved = readFTP.rename(ftpRoot + file.getName(), file.getName());
        log.info("{} moved to error:{}", file.getName(), moved);
    }
    for (File file : this.files) {
        boolean deleted = file.delete();
        if (!deleted) {
            log.warn("{} temp file was not deleted", file.getAbsolutePath() + file.getName());
        }
    }
}catch(IOException io) {
        log.error("====moved file error =====");
}finally {
    readFTP.disconnect();
}

}

private FTPClient connect() throws IOException {
    FTPClient ftpClient = new FTPClient();
    try {
        ftpClient.setControlEncoding("UTF-8");
        ftpClient.connect(address, port);
        ftpClient.login(username, password);
        int replyCode = ftpClient.getReplyCode();
        ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
        if (!FTPReply.isPositiveCompletion(replyCode)) {
            ftpClient.disconnect();
            log.info("=====連不上ftp，慘了====,返回的code信息爲:[{}]", replyCode);
            throw new IOException();
        }
        return ftpClient;
    } catch (IOException e) {
        log.info("======連接ftp異常，異常信息爲:[{}],causer爲:[{}]======", e.getMessage(), e.getCause());
        throw e;
    }
}

//定義枚舉類型，來區分文件的狀態
enum Folder {
NEW,
DONE,
ERROR
}

}