FTP文件读取

目前项目内部需求是将FTP文件服务器上的各类office和pdf文件读取出来返回给前端进行预览展示

1.配置ftp访问信息，并读取配置

/**
 * ftp配置信息
 */
@Component
@ConfigurationProperties(prefix = "ftp.server")
@Data
public class FtpPropertiesConfig {

    /**
     * IP地址
     */
    private String host;

    /**
     * 端口
     */
    private String port;

    /**
     * 登陆用户名
     */
    private String userName;

    /**
     * 密码
     */
    private String password;
}

2.ftp工具类实现

import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPReply;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import java.io.IOException;
import java.io.InputStream;

/**
 * FTP文件操作工具类
 */
@Component
public class FtpUtils {
    private static final Logger log = LoggerFactory.getLogger(FtpUtils.class);

    public static final String FTP_FILE_PATH = "/home/ftptest/";

    private static FtpPropertiesConfig ftpPropertiesConfig;

    //注入ftp配置
    @Autowired
    private FtpPropertiesConfig ftpConfig;

    @PostConstruct
    public void init(){
        FtpUtils.ftpPropertiesConfig = ftpConfig;
    }

    /**
     * 登陆FTP服务器
     *
     * @param host     FTPServer IP地址
     * @param port     FTPServer 端口
     * @param userName FTPServer 登陆用户名
     * @param password FTPServer 登陆密码
     * @return FTPClient
     * @throws IOException
     */
    public static FTPClient login(String host, String port, String userName, String password) throws IOException{
        FTPClient ftpClient = new FTPClient();
        // 防止中文目录乱码
        ftpClient.setAutodetectUTF8(true);
        ftpClient.setConnectTimeout(60000);
        // 连接FTP服务器
        ftpClient.connect(host, Integer.valueOf(port));

        if (FTPReply.isPositiveCompletion(ftpClient.getReplyCode())) {
            // 登陆FTP服务器
            if (ftpClient.login(userName, password)) {
                // 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"))) {
                    ftpClient.setControlEncoding("UTF-8");
                }else {
                    ftpClient.setControlEncoding("GBK");
                }

                // 设置传输的模式，以二进制流的方式读取
                ftpClient.setFileType(FTPClient.BINARY_FILE_TYPE);
                log.info("FTP服务连接成功！");
            }else {
                log.error("FTP服务用户名或密码错误！");
                disConnection(ftpClient);
            }
        }else {
            log.error("连接到FTP服务失败！");
            disConnection(ftpClient);
        }
        return ftpClient;
    }

    /**
     * 关闭FTP服务链接
     * @throws IOException
     */
    private static void disConnection(FTPClient ftpClient) throws IOException {
        if(null != ftpClient && ftpClient.isConnected()){
            ftpClient.disconnect();
        }
    }

    /**
     * 获取文件夹下的所有文件信息
     * @param path 文件路径
     */
    public static FTPFile[] getFTPDirectoryFiles(String path) throws IOException {
        FTPFile[] files = null;
        FTPClient ftpClient = null;
        try {
            ftpClient = login(ftpPropertiesConfig.getHost(), ftpPropertiesConfig.getPort(),
                ftpPropertiesConfig.getUserName(), ftpPropertiesConfig.getPassword());
            // 判断是否存在该目录
            if (!ftpClient.changeWorkingDirectory(path)) {
                log.error("该目录不存在,filePath="+path);
            }
            //调用FTPClient.enterLocalPassiveMode();这个方法的意思就是每次数据连接之前，
            // ftpclient告诉ftp server开通一个端口来传输数据
            ftpClient.enterLocalPassiveMode();
            files = ftpClient.listFiles();
        }catch (Exception e){
            //关闭连接
            disConnection(ftpClient);
            log.error("FTP读取数据异常！", e);
        }finally {
            disConnection(ftpClient);
        }
        return files;
    }

    public static InputStream getFTPFileStream(String filePath,String fileName) throws IOException {
        FTPClient ftpClient = null;
        try {
            ftpClient = login(ftpPropertiesConfig.getHost(), ftpPropertiesConfig.getPort(),
                ftpPropertiesConfig.getUserName(), ftpPropertiesConfig.getPassword());
            // 判断是否存在该目录
            if (!ftpClient.changeWorkingDirectory(filePath)) {
                log.error("该目录不存在,filePath="+filePath);
            }
            // 设置被动模式，开通一个端口来传输数据
            ftpClient.enterLocalPassiveMode();
            InputStream inputStream = ftpClient.retrieveFileStream(fileName);
            return inputStream;
        }catch (Exception e){
            //关闭连接
            disConnection(ftpClient);
            log.error("FTP读取文件流异常！", e);
        }finally {
            disConnection(ftpClient);
        }
        return null;
    }

}

/**
     * 递归遍历出目录下面所有文件
     * @param pathName
     * @throws IOException
     */
    private void listFilesByKey(String pathName) throws IOException {
        if(pathName.startsWith("/")&&pathName.endsWith("/")){
            FTPFile[] files = FtpUtils.getFTPDirectoryFiles(pathName);
            if (null == files){
                return;
            }

            for (int i = 0; i < files.length; i++) {

                if(files[i].isFile()){
                    // 如果是文件则进行处理
                    String fileName = files[i].getName();
                    // do something

                }else if (files[i].isDirectory()){
                    if (!".".equals(files[i].getName()) && !"..".equals(files[i].getName())) {
                        log.info("listFilesByKey：directoryName="+files[i].getName());
                        // 递归调用获取子目录下的文件
                        listFilesByKey(pathName + files[i].getName() + "/");
                    }
                }
            }
        }
    }

 

/**
     * 删除本地目录和文件
     * @param filePath
     * @return
     */
    private boolean deleteDirectory(String filePath) {
        File dirFile = new File(filePath);
        if (dirFile.isDirectory()) {
            File[] children = dirFile.listFiles();
            log.info("deleteDirectory: files count = "+children.length);

            //递归删除目录中的子目录下
            for (int i=0; i< children.length; i++) {
                if (children[i].isFile()) {
                    children[i].delete();
                    log.info("deleteDirectory: remove fileName = "+ children[i].getAbsolutePath());
                }else {
                    deleteDirectory(children[i].getAbsolutePath());
                }
            }
        }
        // 删除为空目录
        log.info("deleteDirectory: remove directory = "+ dirFile.getAbsolutePath());
        return dirFile.delete();
    }

 以上就是涉及ftp文件的读取的操作方法，项目使用场景中暂无上传和更新的操作，如有纰漏欢迎吐槽。