Java对文本文件MD5加密并ftp传送到远程主机目录的实现方法

这里提供一种Java对文本文件MD5加密并ftp传送到远程主机目录的实现方法，共分为以下几个步骤：

步骤一：导入必要的依赖库

Java的MD5加密算法和FTP传输需要用到两个依赖库：commons-codec和commons-net。所以，需要在Java项目中导入相应的依赖库，示例代码如下：

<dependency>
     <groupId>commons-codec</groupId>
     <artifactId>commons-codec</artifactId>
     <version>1.14</version>
</dependency>
<dependency>
     <groupId>commons-net</groupId>
     <artifactId>commons-net</artifactId>
     <version>3.6</version>
</dependency>

步骤二：获取文件MD5值

Java的MD5算法需要使用MessageDigest类。以下是获取文本文件MD5值的示例代码：

import java.io.*;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;

public class FileMd5Util {
    public static String fileMd5(String fileName) throws Exception {
        FileInputStream in = new FileInputStream(fileName);
        MessageDigest md5 = MessageDigest.getInstance("MD5");
        byte[] buffer = new byte[1024];
        int length;
        while ((length = in.read(buffer)) != -1) {
            md5.update(buffer, 0, length);
        }
        in.close();
        return new String(org.apache.commons.codec.binary.Hex.encodeHex(md5.digest()));
    }
}

步骤三：FTP传输文件

Java的FTP传输需要使用FTPClient类。以下是FTP传输文件的示例代码：

import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import java.io.*;

public class FtpUtil {
    public static void ftpUpload(String localFilePath, String remoteFilePath, String remoteHost, String username, String password) throws Exception {
        FTPClient ftpClient = new FTPClient();
        FileInputStream fis = new FileInputStream(localFilePath);
        ftpClient.connect(remoteHost);
        ftpClient.login(username, password);
        ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
        ftpClient.changeWorkingDirectory(remoteFilePath);
        ftpClient.storeFile(new File(localFilePath).getName(), fis);
        fis.close();
        ftpClient.logout();
        ftpClient.disconnect();
    }
}

步骤四：整合实现

将上述两种操作整合起来，即可实现Java对文本文件MD5加密并ftp传送到远程主机目录。示例代码如下：

import org.apache.commons.codec.binary.Hex;
import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import java.io.FileInputStream;
import java.io.File;

public class FileTransferUtil {
    public static void main(String[] args) throws Exception {
        String localFile = "D:\\test.txt";
        String remoteFile = "/data/ftp/test/";
        String remoteHost = "192.168.0.1";
        String username = "ftpuser";
        String password = "ftppassword";

        String md5 = getMD5(localFile);
        String remoteFileName = md5 + ".txt";

        ftpUpload(localFile, remoteFile, remoteFileName, remoteHost, username, password);
    }

    public static String getMD5(String fileName) throws Exception {
        FileInputStream in = new FileInputStream(fileName);
        MessageDigest md5 = MessageDigest.getInstance("MD5");
        byte[] buffer = new byte[1024];
        int length;
        while ((length = in.read(buffer)) != -1) {
            md5.update(buffer, 0, length);
        }
        in.close();
        return new String(Hex.encodeHex(md5.digest()));
    }

    public static void ftpUpload(String localFilePath, String remoteFilePath, String remoteFileName, String remoteHost, String username, String password) throws Exception {
        FTPClient ftpClient = new FTPClient();
        FileInputStream fis = new FileInputStream(localFilePath);
        ftpClient.connect(remoteHost);
        ftpClient.login(username, password);
        ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
        ftpClient.changeWorkingDirectory(remoteFilePath);
        ftpClient.storeFile(remoteFileName, fis);
        fis.close();
        ftpClient.logout();
        ftpClient.disconnect();
    }
}

其中，String localFile设置为需要传送的文件本地地址，String remoteFile设置为远程主机目录地址，String remoteHost设置为远程主机IP地址，String username和String password分别为远程主机FTP登录用户名和密码。

另外，为了避免生成的MD5值在不同操作系统中的不一致，此处使用new String(Hex.encodeHex(md5.digest()))将byte数组转换成字符串。