java怎么ftp jar包 java ftp下载文件

1、添加对应的maven依赖

<dependency>
    <groupId>com.jcraft</groupId>
    <artifactId>jsch</artifactId>
    <version>0.1.51</version>
</dependency>
<!--  jsch 所依赖的jar包 -->
<dependency>
    <groupId>com.jcraft</groupId>
    <artifactId>jzlib</artifactId>
    <version>1.0.7</version>
</dependency>

2、在.properties进行配置ftp的对应信息

#服务器IP地址 ftp.host= 127.0.0.1 #ftp端口号 ftp.port=22 #ftp用户名 ftp.name=test #ftp密码 ftp.password=test #ftp上传文件目录 ftp.directory=/app/img #文件下载保存目录 ftp.saveFile=

3、通过@Value进行获取对应的ftp服务信息

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

/**
 * @author zhouzenghui
 * @title: Ftp
 * @description: ftp信息；类
 * @date 2019/7/10 17:58
 */
@Component
public class Ftp {

    public static String host;

    public static int port;

    public static String user;

    public static String password;

    public static String directory;

    public static String saveFile;

    @Value("${ftp.host}")
    public  void setHost(String host) {
        Ftp.host = host;
    }

    @Value("${ftp.port}")
    public  void setPort(int port) {
        Ftp.port = port;
    }

    @Value("${ftp.name}")
    public  void setUser(String user) {
        Ftp.user = user;
    }

    @Value("${ftp.password}")
    public  void setPassword(String password) {
        Ftp.password = password;
    }

    @Value("${ftp.directory}")
    public  void setDirectory(String directory) {
        Ftp.directory = directory;
    }

    @Value("${ftp.saveFile}")
    public  void setSaveFile(String saveFile) {
        Ftp.saveFile = saveFile;
    }
}

4、进行对应的实现

import com.jcraft.jsch.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.Properties;
import java.util.Vector;

/**
 * @author zhouzenghui
 * @title: FtpJSch
 * @description: TODO
 * @date 2019/7/10 15:11
 */
public class FtpJSch {

    private final static Logger logger = LoggerFactory.getLogger(FtpJSch.class);

    private static ChannelSftp sftp = null;

    private static Session sshSession = null;

    /**
     * 建立连接
     *
     * @return
     */
    public static FtpJSch getConnect() {
        FtpJSch ftp = new FtpJSch();
        try {
            JSch jsch = new JSch();

            //获取sshSession  账号-ip-端口
            sshSession = jsch.getSession(Ftp.user, Ftp.host, Ftp.port);
            //添加密码
            sshSession.setPassword(Ftp.password);
            Properties sshConfig = new Properties();
            //严格主机密钥检查
            sshConfig.put("StrictHostKeyChecking", "no");

            sshSession.setConfig(sshConfig);
            //开启sshSession链接
            sshSession.connect();
            //获取sftp通道
            Channel channel = sshSession.openChannel("sftp");
            //开启
            channel.connect();
            sftp = (ChannelSftp) channel;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return ftp;
    }

    /**
     * 断开连接
     */
    public static void disconnect() {
        //断开sftp连接
        if (sftp != null) {
            sftp.disconnect();
            logger.debug("SSH Channel disconnected.channel={}", sftp);
        }
        //断开sftp连接之后，再断开session连接
        if (sshSession != null) {
            sshSession.disconnect();
            logger.debug("SSH session disconnected.session={}", sshSession);
        }

    }

    /**
     * 上传文件
     *
     * @param uploadFile 上传文件的路径
     * @return 服务器上文件名
     */
    public static String upload(String uploadFile) {
        File file = null;
        String fileName = null;
        try {
            sftp.cd(Ftp.directory);
            file = new File(uploadFile);
            //获取原文件名
            fileName = file.getName();
            //调用ftp进行上传
            sftp.put(new FileInputStream(file), fileName);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return file == null ? null : fileName;
    }

    /**
     * 下载文件
     *
     * @param downloadFileName 下载文件名
     */
    public void download(String downloadFileName) {
        try {
            sftp.cd(Ftp.directory);

            File file = new File(Ftp.saveFile);

            sftp.get(downloadFileName, new FileOutputStream(file));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 删除文件
     *
     * @param deleteFile 要删除的文件名字
     */
    public void delete(String deleteFile) {
        try {
            sftp.cd(Ftp.directory);
            sftp.rm(deleteFile);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 列出目录下的文件
     *
     * @param directory 要列出的目录
     * @return
     * @throws SftpException
     */
    public Vector listFiles(String directory)
            throws SftpException {
        return sftp.ls(directory);
    }


//    public static void main(String[] args) {
//        FtpJSch.getConnect();
//        String filename = FtpJSch.upload("D:\\22.pdf");
//        disconnect();
//        System.out.println(filename);
//    }
}

5、测试

@Test
public void contextLoads() {
    System.out.println(this.host);
    FtpJSch.getConnect();
    String filename = FtpJSch.upload("D:\\22.pdf");
    FtpJSch.disconnect();
}

测试结果