java上传文件到远程服务器

你好，关于Java上传文件到远程服务器的问题，可以使用FTP协议来实现。以下是一个简单的示例：

import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPReply;

import java.io.*;

public class FileUploader {

    private String server;
    private int port;
    private String username;
    private String password;

    public FileUploader(String server, int port, String username, String password) {
        this.server = server;
        this.port = port;
        this.username = username;
        this.password = password;
    }

    public boolean uploadFile(File file, String remoteDir) {
        FTPClient ftp = new FTPClient();

        try {
            ftp.connect(server, port);
            int reply = ftp.getReplyCode();
            if (!FTPReply.isPositiveCompletion(reply)) {
                ftp.disconnect();
                System.err.println("FTP server refused connection.");
                return false;
            }

            boolean success = ftp.login(username, password);
            if (!success) {
                System.err.println("Could not login to the FTP server");
                return false;
            }

            success = ftp.changeWorkingDirectory(remoteDir);
            if (!success) {
                System.err.println("Remote directory does not exist on the FTP server");
                return false;
            }

            ftp.setFileType(FTP.BINARY_FILE_TYPE);

            FileInputStream in = new FileInputStream(file);
            success = ftp.storeFile(file.getName(), in);
            in.close();
            if (!success) {
                System.err.println("Could not upload file to the FTP server");
                return false;
            }

            ftp.logout();
            ftp.disconnect();

            return true;
        } catch (IOException ex) {
            System.err.println("IOException: " + ex.getMessage());
            return false;
        }
    }
}

以上代码中的 `FileUploader` 类可以用于上传本地文件到FTP服务器。在使用时，可以通过以下代码来上传文件：

File file = new File("path/to/local/file");
String remoteDir = "/path/on/ftp/server";
FileUploader uploader = new FileUploader("ftp.server.com", 21, "username", "password");
boolean success = uploader.uploadFile(file, remoteDir);

其中 `server`、`port`、`username`、`password` 表示FTP服务器的地址、端口、登录账号和密码，`file` 和 `remoteDir` 分别表示要上传的本地文件和远程目录。

希望能帮到你。