JAVA 파일 업로드, 다운로드 예제

Java 파일 업로드와 다운로드 코드 예제입니다. 

• io file copy
• FTP
• httpClient, multiparts

---

 

copy

io file 패키지의 copy 방식으로 파일 업로드, 다운로드 하는 코드 예제

 

Upload

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class FileUploadExample {
    public static void main(String[] args) {
    	// 업로드 할 파일 위치
        String sourceFilePath = "C:\\local\\directory\\file.txt";
        // 업로드 위치
        String destinationFilePath = "C:\\remote\\directory\\file.txt";
        
        Path sourcePath = Paths.get(sourceFilePath);
        try (InputStream inputStream = new FileInputStream(sourcePath.toFile())) {
            Files.copy(inputStream, Paths.get(destinationFilePath));
        } catch (IOException ex) {
            System.out.println("Error: " + ex.getMessage());
            ex.printStackTrace();
        }
    }
}

 

Download

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class FileDownloadExample {
    public static void main(String[] args) {
    	// 다운로드 할 파일 위치
        String sourceFilePath = "C:\\remote\\directory\\file.txt";
        // 다운로드 받을 위치
        String destinationFilePath = "C:\\local\\directory\\file.txt";
        
        Path destinationPath = Paths.get(destinationFilePath);
        try (OutputStream outputStream = new FileOutputStream(destinationPath.toFile())) {
            Files.copy(Paths.get(sourceFilePath), outputStream);
        } catch (IOException ex) {
            System.out.println("Error: " + ex.getMessage());
            ex.printStackTrace();
        }
    }
}

 

sourceFilePath 및 destinationFilePath 값을 업로드/다운로드할 파일에 적합한 값으로 바꿔서 사용하면 됩니다.

 

 

반응형

FTP

FTP패키지를 이용하여 FTP 서버로 파일 업로드, 다운로드 하는 코드 예제

 

Upload

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;

public class FTPUploadExample {
    public static void main(String[] args) {
    	//FTP 서버
        String server = "ftp.example.com";
        int port = 21;
        
        String user = "username";
        String password = "password";
        
        //원격 파일 위치
        String remoteFilePath = "/remote/directory/file.txt";
        
        //로컬 파일 위치
        String localFilePath = "C:\\local\\directory\\file.txt";
        
        FTPClient ftpClient = new FTPClient();
        
        try {
        
            ftpClient.connect(server, port);
            ftpClient.login(user, password);
            ftpClient.enterLocalPassiveMode();
            ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
            
            File localFile = new File(localFilePath);
            FileInputStream inputStream = new FileInputStream(localFile);
            ftpClient.storeFile(remoteFilePath, inputStream);
            inputStream.close();
            
            ftpClient.logout();
            
        } catch (IOException ex) {
            System.out.println("Error: " + ex.getMessage());
            ex.printStackTrace();
        } finally {
            try {
                if (ftpClient.isConnected()) {
                    ftpClient.disconnect();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    }
}

 

Download

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;

public class FTPDownloadExample {
    public static void main(String[] args) {
    	//FTP 서버
        String server = "ftp.example.com";
        int port = 21;
        
        String user = "username";
        String password = "password";
        
        //원격 파일 위치
        String remoteFilePath = "/remote/directory/file.txt";
        
        //로컬 파일 위치
        String localFilePath = "C:\\local\\directory\\file.txt";
        
        FTPClient ftpClient = new FTPClient();
        
        try {
        
            ftpClient.connect(server, port);
            ftpClient.login(user, password);
            ftpClient.enterLocalPassiveMode();
            ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
            
            File localFile = new File(localFilePath);
            FileOutputStream outputStream = new FileOutputStream(localFile);
            ftpClient.retrieveFile(remoteFilePath, outputStream);
            outputStream.close();
            
            ftpClient.logout();
            
        } catch (IOException ex) {
            System.out.println("Error: " + ex.getMessage());
            ex.printStackTrace();
        } finally {
            try {
                if (ftpClient.isConnected()) {
                    ftpClient.disconnect();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    }
}

 

서버, 포트, 사용자, 암호, remoteFilePath 및 localFilePath 값을 FTP 서버 및 업로드/다운로드할 파일에 적합한 값으로 바꿉니다.

 

 

Apache HttpClient

HttpClient 패키지를 이용하여 서버로 파일 업로드, 다운로드 하는 코드 예제

Upload

import java.io.File;
import java.io.IOException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;

public class FileUploadExample {
    public static void main(String[] args) throws IOException {
    	
        //파일 위치
        String filePath = "C:\\local\\directory\\file.txt";
        //업로드 URL
        String uploadUrl = "http://example.com/upload";
        
        File file = new File(filePath);
        HttpEntity entity = MultipartEntityBuilder.create()
            .addBinaryBody("file", file, ContentType.APPLICATION_OCTET_STREAM, file.getName())
            .build();

        HttpPost request = new HttpPost(uploadUrl);
        request.setEntity(entity);

        HttpClient httpClient = HttpClientBuilder.create().build();
        HttpResponse response = httpClient.execute(request);

        String responseBody = EntityUtils.toString(response.getEntity());
        System.out.println(responseBody);
        
    }
}

 

Download

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClientBuilder;

public class FileDownloadExample {
    public static void main(String[] args) throws IOException {
    	//다운로드 파일 URL
        String downloadUrl = "http://example.com/download/file.txt";
        //다운로드 위치
        String savePath = "C:\\local\\directory\\file.txt";
        
        HttpGet request = new HttpGet(downloadUrl);

        HttpClient httpClient = HttpClientBuilder.create().build();
        HttpResponse response = httpClient.execute(request);

        File file = new File(savePath);
        FileOutputStream outputStream = new FileOutputStream(file);
        response.getEntity().writeTo(outputStream);
        outputStream.close();
        
    }
}

filePath 및 uploadUrl의 값을 적합한 값으로 바꿔서 사용합니다.